THE
USEFUL ARTS
EMPLOYED IN
THE CONSTRUCTION OF
DWELLING HOUSES.

THE SECOND EDITION.

LONDON:

JOHN W. PARKER, WEST STRAND.

MDCCCLI.

LONDON:
SAVILL AND EDWARDS, PRINTERS,
CHANDOS STREET.

PREFACE.

The dwellings of mankind, at first rude and simple in the extreme, increase in complexity as their inhabitants advance in civilization. Primitive dwellings are scarcely distinguished by signs of superior skill or sagacity above the holes and nests of the lower animals. The hut of the Hottentot may be considered as an inverted nest, and it is certainly not more ingenious than the nests of many birds; but where man constructs such a habitation for himself, he is invariably in a low state of civilization. The wants of the bird are few and simple, and the nest is a temporary abode annually constructed and annually deserted: the wants of man, in a state of nature, are almost as limited, and thus the Hottentot’s hut affords him as good a nest as he desires. But when he steps forth into the rank which the Creator has destined him to fill; when he feels that he is a responsible being, the creation of an Almighty Power to whom worship is due; when he finds that the productions of the earth are capable of being rendered useful to him by the exercise of his ingenuity, and that his own mental powers are capable of being developed by communion with, and by the assistance of his fellow-men;—then the hut—the inverted nest—is no longer equal to his necessities. He makes implements, and he must have a place to shelter them; he cultivates grain, and he requires a store-house for it; he collects and records the thoughts and the wisdom of his predecessors, and he must have a roof to cover these precious mementos: unlike other animals, he requires fire for the preparation of the greater portion of his food; and his fire, as well as his utensils, must be well defended from without:—in short, his wants are so multiplied by the cultivation of his reason, that a house has become necessary to him. The beasts of the field and the birds of the air have certain natural instincts given to them which guide them through life, and are perpetuated in their offspring; the same routine goes on race after race without the operation of what we term improvement. Not so with man: he is a progressive being: he steps forth beyond the limits of mere animal life, and has a mental existence, with wants created by it, and depending on it; wants which are not known to him when considered as a mere animal.

The building of houses has in all ages formed part of the employment of man as he advanced from a state of mere barbarism to one of comparative civilization. In devoting this little volume, therefore, to the subject of the Application of the Useful Arts to the construction of Dwellings, it is necessary to set a limit to so large a subject. A wigwam is a house,—so is a palace, and examples of every possible gradation between the two might be given. In order, then, to avoid the seeming ambition of grasping the whole of this extensive subject we shall not travel out of our own country; nor shall we ascend to the very highest, or descend to the very lowest class of dwellings; but shall describe the principal arts concerned in building a modern English house of moderate rank. In so doing, we shall treat the subject under a few simple heads, classified mainly according to the materials employed.

CONTENTS.

The Useful Arts Employed in the Construction of Dwelling-Houses.

Chapter I.
THE WALLS. STONE AND STONE-WORK.

The material mainly employed in the construction of buildings depends partly on the purpose for which the buildings are intended, and still more, perhaps, on the prevailing geological character of the surrounding country. In such a place as London, where there is an immense mass of tenacious clay beneath the vegetable soil, and where solid stone is not to be had, except by bringing it, at a great expense, from a distance of many miles, clay seems to be the natural material for dwellings; and thus we find that almost all the London houses are built of brick formed of clay. In other parts of Great Britain, such as Glasgow or Edinburgh, the case is very different; for, in those places, clay is scarce, and stone is plentiful. There are quarries not far from Edinburgh, and others within the very precincts of Glasgow, where an abundant supply of good building-stone is obtained at a very low rate. Hence it follows as a natural consequence, that the houses in those two cities exhibit a large proportion of stone structures; so much so, indeed, that an inhabitant of London, who is accustomed to see stone appropriated only to large important public buildings, is apt to imagine that the houses in the two northern cities must necessarily be very costly. This is by no means certain, however, for the builders in each city make use of those materials which may be most available.

Whether stone form the main portion of the walls of a house, as in the cases just named, or whether it is only used in smaller degree, as in London houses, the operations by which it is worked and fitted are pretty much the same; and we will therefore devote this chapter to a brief description of the principal kinds of building-stone, followed by an outline of the Mason’s operations.

Principal Varieties of Building-stone.

Granites are rocks which have been formed by the union of three different minerals in a state of fusion; these, on cooling, have crystallized and become distinct from each other in the mass. It is on the varied proportions in which these three constituents are combined, that the colour, hardness, durability, and beauty of the various granites depend. The light-red and rose-coloured granites contain the felspar in greatest abundance and in the largest crystals; but this mineral varies in hue from the purest white to nearly black; it is the ingredient most acted on by the atmosphere; the rock, therefore, which abounds in it, though it may be more beautiful to the eye, and more easily worked at first, is not so durable as that which contains it in smaller crystals, and with a larger proportion of quartz. It is to this last-named mineral that granite owes the sparkling appearance which it presents when the sun shines on it; quartz is the hardest and most imperishable of the three minerals which form the granite-rock. The third, mica, is distinguishable from the other two by its satiny, shining, dark hue, and is very apparent in the coarse-grained, handsome stone of our own country, brought from Cornwall.

When the felspar is replaced by another mineral called hornblende, the stone is of a dark-greenish hue, and the component parts are in a finer form and less distinguishable from each other. The Aberdeen granite is an example of this kind, which is more durable than the former, though not so pleasing to the eye.

Granite occurs in all the larger mountain-ranges, and in isolated masses in every country; not being a stratified rock, and being excessively hard, it is difficult to quarry and get out in manageable masses. Blasting with gunpowder is the mode usually employed in this country; the pieces detached by this means are hewn roughly into form on the spot by a small pickaxe. Aberdeen granite is quarried by cutting a deep line some yards long, and placing strong iron wedges at equal distances in this line; these wedges are struck in succession by heavy hammers till the mass splits down. This, or analogous modes, may always be employed when the rock approaches a slaty or stratified structure, as is the case with some nearly related to granite. Another method of detaching masses of rock, is by driving wooden wedges into a deep fissure, either natural or artificial; the wedges are then wetted, and the consequent expansion of the wood bursts the rock asunder.

As granite has always to be brought from a great distance to the spot where it is wanted, because its natural localities are far from the places where edifices are usually constructed, and also on account of its hardness, this rock is only used for important buildings, such as bridges, markets, churches, &c., and not commonly even for these. London and Waterloo bridges, Covent Garden and Hungerford markets, and the York column in Pall Mall, are instances of its use in London.

The principal kinds of stone used in building are the LIMESTONES, or calcareous rocks of the geologist; of these it would be useless to describe or enumerate more than a few. In our own country, the Portland stone, so called from its principal quarries being in Portland Island, in Dorsetshire, holds the first rank, and is that almost exclusively used in London for building, and for the ornamental parts of edifices. It unites the qualities of being easily sawn and worked, when lately quarried, and of subsequently hardening by exposure to the air; it is close and even in its texture, admitting of being wrought into delicate work, and receiving a very smooth surface, which it will retain for a considerable period, though it is surpassed in durability by many other rocks. It is said that the Banquetting-house, Whitehall, was the first building in London in which this stone was employed. St. Paul’s, Westminster and Blackfriars’ bridges, Newgate, and, indeed, most of the public buildings of the metropolis, are examples of its use.

Bath-stone, so called from its being entirely used in the neighbourhood of that city, is softer and far less durable than the preceding. When recently quarried, it may be sawn with a toothed saw, like timber, and can be carved with the greatest facility into the richest ornaments; hence it is often employed, and, if sheltered from the weather, is well adapted for such purposes, from its rich, even cream colour; but though it hardens considerably by exposure, it is acted upon, after a time, by the air, so as to render it very perishable. The restoration of Henry the Seventh’s Chapel, Westminster, is, unfortunately, made with this stone.

The two preceding, and many others, distinguished by names according to the principal localities, as Oxford-stone, Ketton-stone, &c., belong to what geologists term the Oolitic formation, from the resemblance of some kinds of the rock to fishes’ roe, which is observable in that we have last mentioned. They all agree in their principal qualities.

Purbeck-stone, also from Dorsetshire, is used for steps, paving, door-sills, and copings; it is coarser, harder, and less uniform in texture than the foregoing, and not, therefore, calculated for fine buildings, except for the purposes we have specified.

Yorkshire-stone resembles the last; it is used for the same purposes, but especially for paving. The greatest part of the foot-paths in the streets of London are laid with this or the preceding.

Rag-stone is obtained from quarries on the banks of the Thames, Medway, &c. It was the stone chiefly used for building in ancient London, and a great deal is still used for paving.

The lower chalk, which is of a grey colour, and contains masses of flint, was formerly much employed for building in the south-western counties of England; its good qualities are proved by the perfect state of many old churches in that part of the kingdom, which are known to be from seven to nine hundred years old. It is now only sparingly used in farm-building and cottages, but it is consumed in vast quantities to burn into lime for mortar and other purposes, and as a manure.

Belonging to the same family of calcareous rocks, and next in utility to those we have just enumerated, though far surpassing them in beauty and value, stand the endless varieties of Marbles, essentially characterized by their crystalline texture, superior hardness, and by the absence of shells or organic remains found so abundantly in all other limestones. The name of marble is, however, popularly given to many stones not possessing these characters, but which are hard enough to be susceptible of a high polish, and are ornamental when so treated. In this country the finer kinds of real marble are only sparingly employed in the decorative departments of architecture, such as, for chimney-pieces, slabs, hearths, capitals of columns in halls, saloons, monuments, &c. The secondary kinds are also employed for similar purposes, but more abundantly. The cold white statuary marble is not adapted for out-of-door use in our foggy and cloudy climate, under the influence of which it would soon become dingy and disagreeable, as is proved by the total failure in the effect of the little triumphal arch erected before Buckingham Palace. In Italy many ancient and modern edifices are faced with white marble, and in that clear and pure atmosphere they retain the beauty of the material for ages. The use to which the finest marbles of Greece and Italy are applied in sculpture, is familiar to every one.

The last class of rocks employed in building, in those localities where they occur, are the Sandstones, silex, or flint, in finely-comminuted particles agglutinated together, being their principal ingredient; they constitute excellent building-stone, and are abundantly used as such in the West of England.

On Quarrying Stone.

A quarry is an excavation made in the ground, or among rocks, for the purpose of extracting stone for building, or for sculpture. The name appears to have originated in the circumstance that the stones, before they are removed to a distance, are first quadrated, or formed into rectangular blocks.

The following may be taken as an example of the general operations of quarrying building-stones. If the stone be vertically below the surface of the ground, the quarrymen first remove the earth and surface soil, and then dig a perpendicular shaft, or pit, to afford access to the stone; but if, as frequently happens, the stone be within the flank of a hill, or mountain, the quarrymen excavate horizontal galleries into the hill, leaving pillars here and there to support the superincumbent mass. Supposing a large quarry about to be opened beneath the soil, the earth is first removed, and then a sort of inferior stone called “rag,” which generally lies between the soil and the good stone beneath. Large masses of available stone generally consist of distinct strata lying close together in a kind of cemented bulk, and the contiguous surfaces forming cleavages, greatly assist the quarrymen in detaching blocks from the mass. The block is always more easily separated in a direction parallel to these planes of cleavage than in any other direction, and the operations are, therefore, guided by this circumstance. The workmen drive a series of iron wedges into the mass of stone parallel to the cleavage-planes; and, after a few blows, a portion of the mass becomes separated in that direction. They then measure off a portion equal to the intended length and breadth of the stone, and drive their iron wedges similarly in these directions, by which the piece is entirely severed from the rocky mass. The cleavage-planes vary interminably in direction, so that the quarrymen have to work in various positions, according to the direction of stratification. The operations are more easily conducted when the cleavage-planes are vertical, than in any other direction. After the blocks have been severed, they are brought to an irregularly square shape, by means of a tool called a kevel; and are finally hoisted by cranes on to low trucks, and conveyed on tram-ways out of the quarry; or else are hoisted to the surface of the quarry at once, if the depth render that plan necessary.

In quarrying sandstone, and those rocks which consist of regular layers, the pick, the wedge, the hammer, and the pinch, or lever, are the chief tools. But for many kinds of limestone, and for greenstone and basalt, recourse is had to the more violent and irregular effects of gunpowder. Indeed, some of the primitive rocks, such as granite, gneiss, and sienite, could scarcely be torn asunder by any other means. The great objection to blasting by gunpowder is, that the blocks are broken irregularly, and much of the stone is wasted; but it has the advantage of being simple in its application, and powerful in its effects. The grains of powder are suddenly converted into a permanently elastic air, occupying about four hundred and seventy-two times more space than their own bulk. The elastic fluid expands with a velocity calculated at the rate of about ten thousand feet per second; and its pressure or force, when thus expanding, has been estimated as equal to one thousand atmospheres, that is, one thousand times greater than the atmospheric pressure upon a base of the same extent. By applying this product to a square inch, upon which the atmosphere exerts a pressure of about fifteen pounds, the elastic fluid of the gunpowder will be found, at the moment of the explosion, to exert a force equivalent to six tons and a half upon the square inch of surface exposed to it; and that with a velocity which the imagination can hardly follow.

In boring a rock preparatory to blasting, it is necessary to consider the nature of the stone, and the inclination or dip of the strata, in order to decide upon the diameter, the depth, and direction of the hole for the gunpowder. The diameter of the hole may vary according to the nature of the rock, from half an inch to two and a half inches; and the depth from a few inches to as many feet; the direction may vary to all the angles from the perpendicular to the horizontal. The tools used in this operation are very simple. The chisel, or jumper, as it is called, varies in size according to the work to be performed, and its edge is more or less pointed to suit the hardness of the rock to be bored. If the hole is to be small and not deep, it may be bored by a single person; with one hand he manages the chisel, which he turns at every blow so as to cross the previous cut, and with the other hand he strikes it with a hammer of six or eight pounds’ weight, occasionally clearing out the hole by means of a scraper. But when the hole is large and deep, one man in a sitting posture directs the jumper, pours water into the hole, and occasionally cleans it out, while two or three men, with hammers of ten or twelve pounds’ weight, strike successive blows upon the jumper, until the rock is perforated to the required depth. To prevent annoyance to the workmen, a small rope of straw or hemp is twisted round the jumper, and made to rest in the orifice of the hole. When the holes are to be made to a greater depth than about thirty inches, it is common to use a chisel from six to eight feet in length, pointed at both ends, having a bulbous part in the middle for the convenience of holding it; it thus becomes a kind of double jumper, and is used without a hammer, with either end put into the hole at pleasure. The workmen holding this jumper by the bulbous part, lift it, and allow it to drop into the hole by its own weight, and by this simple operation, a hole to the depth of five feet and upwards is perforated with ease and expedition. When the boring is completed, the fragments are carefully removed, and the hole is made as dry as possible, which is done by filling it partially with stiff clay, and then driving into it a tapering iron rod, called the claying bar, which nearly fills it. This, being forced in with great violence, drives the clay into all the crevices of the rock, and secures the dryness of the hole. Should this plan fail, tin cartridges are used: these are furnished with a stem or tube, as shown in the following figure, through which the powder may be ignited. When the hole is dry, the powder is introduced, mixed sometimes with quicklime, which, it is said, increases the force of the explosion. A long iron or copper rod, called the pricker, is then inserted amongst the powder, and is afterwards withdrawn, when the priming powder is introduced. The hole is filled up with burnt clay, pounded brick, stone, or any other substance not likely to produce a spark during the ramming. This is called the tamping. In filling up the hole, the chief danger is the production of a spark among the materials, a circumstance which has occasioned the most fatal and distressing accidents to quarriers. Prickers and rammers of copper, or of bronze, have been employed, but their greater expense, and liability to twist and break, have prevented their general introduction.

The quarrier is, of course, accustomed to suppose that the more firmly he rams in the powder, the greater will be the resulting effect. It is, however, a curious property of sand, that it fills up all the void spaces in the tube or hole, and for some rocks entirely supersedes the necessity of ramming and pricking.

When the hole is fully charged with the powder and wadding, the pricker is withdrawn, and the small tubular space, or vent-hole, which it leaves, is sometimes filled up with powder; but, for the sake of economy, it is more common to insert straws filled with powder, and joined together, so as to reach the required depth. The lower straw is one terminating in the root part, where a natural obstruction occurs, or it is artificially stopped with clay to prevent the powder from being lost. The lower part of the priming straw is pared quite thin, so as to insure the inflammation of the charge of powder in the hole. Sometimes the fire is conveyed by means of the large and long green rushes, which grow in marshy ground. A slit is made in one side of the rush, along which the sharp end of a bit of stick is drawn, so as to extract the pith, when the skin of the rush closes again by its own elasticity. This tube is filled up with gunpowder; it is then dropped into the vent-hole, and made steady with a bit of clay. This being done, a slow match, called a smift, consisting generally of a bit of soft paper, prepared by dipping it into a solution of saltpetre, is carefully applied to the priming powder. When this match is about to be fired, the quarriers usually blow a horn or ring a bell, to give notice to all around them to retire. The explosion commonly takes place in about a minute; the priming first explodes, attended only with flame; a short interval of suspense commonly ensues; the eyes of the bystanders being anxiously directed towards the spot; the rock is instantly seen to open, when a sharp report or detonating noise takes place, and numerous fragments of stone are observed to spring into the air, and fly about in all directions, from amidst a cloud of smoke. The quarrier then returns with alacrity to the scene of his operations.

The accompanying figure shows the plan of blasting the rock, and a section of the hole ready prepared for firing. The portion of the rock to be dislodged by the explosion is that included between A and B. The charge of powder is represented as filling the bore to C, from which point to the top, the hole is filled up with tamping. The smift is represented at D.

In the year 1831, a patent was taken out by Mr. Bickford, of Tucking Mill, Cornwall, for an invention called “the Miner’s Safety Fuse.” It consists essentially of a minute cylinder of gunpowder, or other suitable explosive mixture, inclosed within a hempen cord, which is first twisted in a peculiar kind of machine, then overlaid to strengthen it; afterwards it is varnished with a mixture of tar and resin to preserve the powder from moisture, and finally is coated with whitening to prevent the varnish from sticking to the fingers, or the fuses to one another. These fuses are said to have been used with good effect, and to have greatly diminished the number of accidents.

The application of Electricity to the Blasting of Rocks.

Perhaps the greatest modern improvement that has been made in blasting rocks has been by the introduction of the galvanic battery. It is well known that by closing the circuit of a voltaic current by means of thin platinum wire, or by fine iron or steel wire, the platinum becomes red-hot, and the iron or steel becomes instantly fused. All, therefore, that is necessary is to connect the two terminal wires of a voltaic battery by means of a fine wire of platinum or iron, and to bury this in gunpowder contained in a tin canister, or a fuse connected with a deposit of gunpowder. This was the method adopted by Colonel Pasley in removing the Royal George, which lay sunk at the bottom of the water at Spithead. Canisters of gunpowder, sometimes to the extent of three thousand pounds’ weight, were employed, and securely deposited in the sunken vessel, by workmen who descended in the diving-bell; the terminal wires of the battery, connected as above stated, having been previously inserted in the canisters, and these wires being extended to a great distance, the explosion took place the instant they were connected with the voltaic battery. After the vessel was thus blown to pieces by repeated explosions, divers descended to clear away the wreck, and to attach guns, &c., to chains let down from a ship above, and which were then hauled up by means of a crane.

Mr. Morgan, in the American Journal of Science, describes a fuse or cartridge which he has used with success in connexion with the voltaic battery. This cartridge is prepared by joining two pieces of clean copper wire to the ends of a fine steel wire, about one quarter of an inch in length, by means of waxed silk; a thin piece of wood is then spliced to both copper wires, to protect the steel wire from accidents, and to enable the maker to introduce it easily into a quill or small paper tube, which is to form the cartridge. This tube is filled with fine gunpowder, and made air and water-tight. Another piece of wood is then attached to this arrangement, and one of the copper wires is bent over so as to form an angle with the straight wire.

When it is required to use this cartridge, the copper wires are rubbed with sand-paper, and twisted round the wires of the voltaic battery. The cartridge is then placed deep in the hole made to receive the gunpowder, and the charge is fired from any distance.

Mr. Morgan found this arrangement very useful in removing stumps of trees; but one of his applications of it was curious and novel: he exploded some powder in a pond at the depth of ten feet, with the battery at the distance of two hundred and ten feet; the explosion, which was instantaneous, had the effect of killing a large eel; and “I have no doubt,” says Mr. Morgan, “that wild-fowl will yet be killed by means of shells placed at low-water on the banks where they feed; and by means of long connecting wires, the shells can be made to explode simultaneously among the birds.”

But the grandest application of gunpowder and the voltaic battery to the blasting of rocks, was made in the month of January, 1843, at Dover. It was determined by these means to attempt the removal of an enormous mass of the cliff facing the sea, which formed an obstruction to the line of railroad. A portion of the cliff which was penetrated by the tunnel made through Shakspeare’s Cliff gave way, about two years previously. About fifty yards of the tunnel were carried away, and a clear space was thus formed for the line of railroad, with the exception of a projecting point, which, prior to the slip alluded to, was the extremity of the part of the cliff pierced by the tunnel, and to remove which was the object of the operation in question.

To clear away this mass by the tedious process of manual labour, would have cost above twelve thousand pounds; and this consideration, as well as the time that would have been lost, induced Mr. Cubitt, the engineer, to try the bold expedient of blowing it away with gunpowder. “It cannot be denied,” remarks Captain Stuart, whose account of this great engineering operation we follow, “that there was apparent danger in the undertaking, for the weight of the mass to be removed was estimated at two million tons, and the quantity of powder used was more than eight tons, or eighteen thousand pounds. The quantity used in blowing up the fortifications of Bhurtpore was twelve thousand pounds, and this is said to have been the greatest explosion that had ever previously taken place for any single specific object.”

The front of the projection was about one hundred yards wide; this front was pierced with a tunnel about six feet in height, and three in breadth; three shafts, equidistant from each other, and from the entrances to the tunnel, were sunk to the depth of seventeen feet, and galleries were run, one from each shaft, parallel with each other, and at right angles with the line of the tunnel. These galleries varied in length, the longest having been twenty-six feet, and the shortest twelve feet, and at their extremities chambers were excavated in a direction parallel with the tunnel. This description will be the better understood by reference to the following figure.

1. The tunnel. 2. The shafts. 3. The galleries. 4. The chambers.

In the chambers, the powder was deposited in three nearly equal quantities; it was done up in fifty-pound bags, and the proportion in each chamber was contained in a wooden case, nearly as large as the chamber itself. Ignition was communicated by means of a voltaic battery; the conducting wires, one thousand feet in length, were passed over the cliff, one to each chamber, and the electricity was communicated in a shed built for the purpose on the top of the cliff, about fifty yards from the edge. The explosion was conducted by Lieutenant Hutchinson, R.E., who was engaged with General Pasley in blowing up the wreck of the Royal George. The time appointed for the explosion to take place, was two o’clock P.M., 26th January, 1843, the tide being then at its lowest ebb. The arrangements, to preserve order and prevent danger, were good. A space was kept clear by a cordon of artillery, and the following programme was issued:—

“Signals, January 26, 1843.

“1st. Fifteen minutes before firing, all the signal flags will be hoisted.

“2nd. Five minutes before firing, one gun will be fired, and all the flags will be hauled down.

“3rd. One minute before firing, two guns will be fired, and all the flags (except that on the point which is to be blasted) will be hoisted up again.”

These signals were given exactly at the specified times, and when the expected moment arrived, a deep subterranean sound was heard, a violent commotion was seen at the base of the cliff, and the whole mass slid majestically down, forming an immense débris at the bottom. Tremendous cheers followed the blast, and a royal salute was fired.

The remarks of different intelligent observers, as to the effects of this explosion, would of course differ according to their position with respect to the scene of explosion. One observer states that “the earth trembled to the distance of half a mile; a stifled report, not loud, but deep, was heard; the base of the cliff, extending on either hand to upwards of five hundred feet, was shot as from a cannon, from under the superincumbent mass of chalk seaward; and in a few seconds not less than a million tons of chalk were dislodged by the shock, and settled gently down into the sea below.”

But the most eminent observer who has described the effects of this explosion is Sir John Herschel, from whose letter to the Athenæum we gather the following particulars. His position was on the summit of the cliff, next adjoining the scene of operations, to the southward, the nearest point to which access was permitted.

Sir John Herschel was particularly struck with “the singular and almost total absence of all those tumultuous and noisy manifestations of power, which might naturally be expected to accompany the explosion of so enormous a quantity (19,000lbs.) of gunpowder.” He describes the noise which accompanied the immediate explosion as “a low murmur, lasting hardly more than half a second, and so faint, that had a companion at my elbow been speaking in an ordinary tone of voice, I doubt not it would have passed unheeded.”

The fall of the cliff, the ruins of which extended over no less than eighteen acres of the beach, to an average depth of fourteen feet, was not accompanied with any considerable noise. “The entire absence of smoke was another and not less remarkable feature of the phenomenon. Much dust, indeed, curled out at the borders of the vast rolling and undulating mass, which spread itself like a semi-fluid body, thinning out in its progress; but this subsided instantly; and of true smoke there was absolutely not a vestige. Every part of the surface was immediately and clearly seen—the prostrate flagstaff (speedily re-erected in the place of its fall)—the broken turf, which a few seconds before had been quietly growing at the summit of the cliff—and every other detail of that extensive field of ruin, were seen immediately in all their distinctness. Full in the midst of what appeared the highest part of the expanding mass, while yet in rapid motion, my attention was attracted by a tumultuous and somewhat upward-swelling motion of the earth, whence I fully expected to see burst forth a volume of pitchy smoke, and from which my present impression is, that gas, purified from carbonaceous matter in passing through innumerable fissures of cold and damp material, was still in progress of escape; but whether so or not, the remark made at the moment is sufficient to prove the absence of any impediment to distinct vision.”

The amount of tremor experienced by Sir John Herschel at the point where he was standing was so slight, that he thinks he has felt it surpassed by a heavy waggon passing along a paved street. “The impression, slight as it was, was single and brief, and must have originated with the first shock of the powder, and not from the subsequent and prolonged rush of the ruins.” We have already noticed the remark of one observer, that “the earth trembled to the distance of half a mile;” but this seems to be a mistake; the writer fancied that it must have been so, and that he should be suspected if he were to state it otherwise. It is to be regretted that people do not endeavour to describe what they see and hear, without the embellishment of the imagination.

This grand experiment was no less grand from the absence of noise, smoke, earthquake, and fragments hurled to vast distances through the air. “I have not heard of a single scattered fragment flying out as a projectile in any direction”—continues Sir John Herschel—“and altogether the whole phenomenon was totally unlike anything which, according to ordinary ideas, could have been supposed to arise from the action of gunpowder. Strange as it may seem, this contrast between the actual and the expected effects, gave to the whole scene a character rather of sublime composure than of headlong violence—of graceful ease than of struggling effort. How quietly, in short, the gigantic power employed performed its work, may be gathered from the fact, that the operators themselves who discharged the batteries were not aware that they had taken effect, but thought the whole affair a failure, until reassured by the shout which hailed its success.”

Sawing the Stones for the Mason.

Whatever may be the purpose to which the stone is to be applied, the larger blocks obtained from the quarry must be cut into smaller and more manageable pieces; this is done by sawing. The saw used is a long blade of steel without teeth, fixed in a heavy wooden frame, similar in principle to that which holds the finer spring-saws employed by cabinet-makers. The stone-saw, from its great size, however, requires a more powerful contrivance for drawing it to the proper degree of tension: this consists of a long screw-bolt fixed to a piece of chain, which hooks over one of the upright arms of the frame; a similar chain from the other carries a swivel-joint with a screw-nut to receive the screw: by turning the swivel by a lever, the nut on the screw draws up or tightens the chains, and that draws the blade tight, which is contained between the other ends of the arms.

These huge saws are worked by one or two men, who, in London stone-yards, sit in watch-boxes, in order to be sheltered from the sun and rain. Barrels filled with water, which is allowed to drop out at a tap, are mounted on the block of stone, so that the water may drip into the cut and facilitate the motion of the saw by removing some of the friction, as well as prevent it becoming hot, and so losing its temper by the same cause.

In some large establishments, the sawing is effected by machinery. The block is fixed in a proper position, and a group of saws brought to act on it. These saws are all arranged parallel, according to the thickness of the pieces into which the stone is to be cut; and a steam-engine being brought to bear on the whole group, the cutting is effected with great rapidity.

The Processes of Stone-Masonry.

When the stone is sawed to the proper size, the surfaces which are exposed to view, have to be made smooth and even. The tools used by the mason for this purpose consist of iron chisels of different widths, and principally of a sharp-pointed one called a pointer; these chisels are struck with a mallet made of a conical-formed lump of hard wood, fixed to a short handle.

Stone-Sawyer.

The pointer is used for chipping off the principal roughnesses on the face and edges, and for working the whole face over to bring it level, the workman trying his work by applying a straight-edge occasionally to it. When the front and edges are made true, the face is sometimes tooled over, so as to leave regular furrows in it, according to certain forms, by which the different kinds of work are distinguished. But this practice is going out of use, now that soft free-stone is so much employed in building. In old edifices, such as St. Paul’s, Whitehall, &c., &c., the stone will be found to be wrought on its face in the manner alluded to.

Stones in buildings are not only fixed with mortar, as bricks are, but are further secured in their places by being clamped together with iron clamps. These are short iron bars, from seven to twelve inches long, one and a half wide, and half an inch thick, according to the size of the stone; the ends of the clamps being turned down a little, to afford a better hold. A channel is cut in the two contiguous stones deep enough for the clamp to lie in, and the ends of the channel are sunk deeper, to receive the turned-down ends of the clamp; when this is put into the channel, molten lead is poured in to fill up the interstices, to keep the clamp in its place, and to prevent it from rusting.

From the expense of carrying and working stone, the walls of buildings at a distance from a quarry, such for example as those in London, are seldom now built of solid stone, but a facing of this material is applied only on the external surface of the wall, which is built of brick. This kind of work is called ashler work, and both the brick and stone-work must be executed with considerable care, to enable a wall composed of two materials to preserve its perpendicularity; it being obvious, that if the brick part yielded to the weight, it must, from its construction, do so more than the stone facing, and, therefore, the wall would bend inwards and become crippled.

The width of the courses of ashlers must, therefore, be made equal exactly to a certain number of courses of bricks with the intervening mortar, and the brick-work must be executed with such care, that this number of courses may be everywhere of the same width in the whole height of the wall. In every course of ashler there must be solid stones laid quite, or nearly quite, across the width of the wall to form a bond to the stone facing, and all the stones of the ashler must be fixed with iron cramps to one another and to these bond-stones. But, however carefully a faced wall may be executed, it is never so firm or durable as one built entirely of either material; indeed, if well executed, of good materials, and of competent thickness in proportion to its height, a brick wall is the most durable, light, and efficient structure that can be erected.

When stone is to be cut into cornices, mouldings, &c., the blocks having been sawed, the ends, top and bottom, are worked very true and parallel, or perpendicular to each other, and one edge or arris cut to a perfectly straight line; a thin wooden mould of the section of the cornice is then applied to each end, and the profile of the mouldings marked out on the stone. The workman being guided by this figure, cuts away the stone down to the general surface of the mouldings, and then proceeds to get the flat fillets of the mouldings perfectly straight and true by the rule; these again guide him in working the curved mouldings, such as ovolos, cavettos, cyma rectas, and ogees; when these are cut nearly to their profile, and perfectly straight on the bed line, they are finished off by being rubbed down smooth by thin long straight-edges of stone.

Foliage and carved work is executed by a better kind of workman, possessing some of the taste of an artist, and he works on the same general principles as a sculptor when executing a statue; it would be foreign to our present object, therefore, to dwell on this branch of the mason’s art.

It often, or even most commonly occurs, that the distance between two columns of a portico, is of greater length than a stone can be obtained, and if the architrave, or that part of the entablature immediately over the capitals of the columns, be looked at attentively, a stone will be perceived between the columns apparently unsupported, for neither end rests on the column, and the joints of those ends are upright, not presenting any character of a voussoir-stone or arch. The contrivance by which such an architrave stone is supported deserves to be described.

The stone in question has a projecting part, wrought at each end, of the form shown in the annexed figure; this projection is received into a corresponding cavity, cut in the end of the stone supported by the column, and the joint is thus really an arched or wedge-shaped one, though the bevel line is concealed, and the two stones, when put together, present only a vertical joint.

The mason uses squares, levels, plumb-lines, and straight-edges to set out his work, and trowels and mortar to set the stones with; but the latter is rather used to make the joints water-tight than to keep the stones together, this being effected by their weight or by iron clamping. Formerly the mason required far more accurate and extensive knowledge of geometry than is possessed by persons of the trade at present; this was when he was called on to construct groined and vaulted roofs, enriched with carved work and pendent corbels, where the nicest workmanship was required, to ensure the stability of the light and graceful columns and vaulting of a Gothic cathedral. It was this possession of superior skill and knowledge that caused the establishment of the Society of Freemasons, which dates its rise from the tenth or eleventh century.

Marble, from its costliness, and the difficulty of working it, is seldom, if ever, used in solid pieces in buildings; thin facings of it are set upon stone backings, much as rare woods are used in veneering by the cabinet-maker. The marble is sawn into thin slabs, like other stone, and the face is polished by rubbing on it the surface of another piece, fine sand, mixed up with water, being used to cause abrasion.

Various contrivances are resorted to for cutting marble, and building-stones generally, into curved forms. In some cases a lever is made to work at one end on a pivot, while at the other end is attached a curved piece of sheet-iron, which passing backwards and forwards over the stone, cuts it in a circular form. In other cases a cylinder of sheet-iron is formed; and this being allowed to fall vertically on the surface of the stone, and rotated rapidly, cuts out a piece of stone of the diameter of the cylinder. Sometimes, when a large circular piece of stone is required, a kind of wheel is employed, furnished on its under surface with four curved cutting-irons, and these cutters, when the wheel revolves, cut the stone. By a modification of the arrangements, an oval instead of a circular curve may be given to the piece of stone.

Chapter II.
ON THE DURABILITY OF STONE BUILDINGS.

“Everything belonging to the earth, whether in its primitive state, or modified by human hands, is submitted to certain and innumerable laws of destruction, as permanent and universal as those which produce the planetary motions. The operations of nature, when slow, are no less sure; however man may for a time usurp dominion over her, she is certain of recovering her empire. He converts her rocks, her stones, her trees, into forms of palaces, houses, and ships; he employs the metals found in the bosom of the earth as instruments of power, and the sands and clays which constitute its surface as ornaments and resources of luxury; he imprisons air by water, and tortures water by fire to change, to modify, or destroy the natural forms of things. But in some lustrums his works begin to change, and in a few centuries they decay and are in ruins; and his mighty temples, framed, as it were, for divine purposes, and his bridges formed of granite, and ribbed with iron, and his walls for defence, and the splendid monuments by which he has endeavoured to give eternity even to its perishable remains, are gradually destroyed; and these structures which have resisted the waves of the ocean, the tempest of the sky, and the stroke of the lightning, shall yield to the operation of the dews of heaven, of frost, rain, vapour, and imperceptible atmospheric influences; and as the worm devours the lineaments of his mortal beauty, so the lichens and the moss, and the most insignificant plants, shall feed upon his columns and his pyramids, and the most humble and insignificant insect shall undermine and sap the foundations of his colossal works, and make their habitations amongst the ruins of his palaces, and the falling seats of his earthly glory.”[1]

Although it is true that all human works must decay, yet it is a point of great importance to ourselves and our successors whether that decay be slow or speedy. The causes enumerated in the above eloquent passage, though sure, are exceedingly slow in their action, and provided the building materials have been selected with reference as well to their durability as to their beauty, the resulting structure may defy the corroding tooth of time for many ages, and we may thus transmit to a long posterity, lasting memorials of our wisdom and science, as well as of our piety. Modern science has, to a very great extent, enabled the architect and builder to determine beforehand what is the durability of any given stone; and it is with great pleasure that we now notice the extensive inquiry made at the suggestion of Mr. Barry, the architect of the new Houses of Parliament, under the Commission issued by Her Majesty’s Government, to investigate the qualities of stone in various parts of the kingdom, in order to select that which should best ensure perpetuity to this grand national monument. This commission, consisting of Mr. Barry, Sir H. T. De la Beche, Dr. W. Smith, and Mr. C. H. Smith, visited one hundred and five quarries, and examined one hundred and seventy-five edifices; and their collected specimens were then submitted to tests, both mechanical and chemical, by Professors Daniell and Wheatstone, of King’s College, London. In order to leave a permanent record of their labours, the Commissioners published a Report, and deposited in the Museum of Economic Geology, a variety of specimens of the stones which they had collected. From this Report, we select such details as are calculated to serve the purposes of popular instruction. The Commissioners did not consider it necessary to extend their inquiries to granites, porphyries, and other stones of similar character, on account of the enormous expense of converting them to building purposes in decorated edifices, and from a conviction that an equally durable, and in other respects more eligible material, could be obtained for the object in view from among the limestones or sandstones of the kingdom.

The Commissioners soon had striking proofs of the necessity and importance of this inquiry in the lamentable effects of decomposition observable in the greater part of the limestone employed at Oxford; in the magnesian limestones of the Minster, churches, and other public edifices at York; and in the sandstones of which the churches and other public buildings at Derby and Newcastle are constructed; and numerous other examples. The unequal state of preservation of many buildings, often produced by the varied quality of the stone employed in them, although it may have been taken from the same quarry, showed the propriety of a minute examination of the quarries themselves, in order to gain a proper knowledge of the particular beds from whence the different varieties have been obtained. An inspection of quarries was also desirable for the purpose of ascertaining their power of supply, and other important matters; for it frequently happens, that the best stone in quarries is often neglected, or only partially worked, in consequence of the cost of laying bare, and removing those beds with which it may be associated; whence it happens, that the inferior material is in such cases supplied.

Stone buildings decay more rapidly in towns than in the open country, where dense smoke, fogs, and vapours, which act injuriously on buildings, do not exist. There is also another curious cause which contributes to the durability of stone buildings situated in the country. In the course of time, the stone becomes covered with minute lichens, which, though in themselves decomposing agents, act with extreme slowness, and when once firmly established over the entire surface of the stone, seem to exercise a protective influence, by defending the surface from the more violent destructive agents; whereas, in populous smoky towns, these lichens are prevented from forming, and thus the stone is exposed to severer trials than stone of the same kind situated in the country.

As a remarkable illustration of the difference in the degree of durability in the same material, subjected to the effects of the air in town and country, the appearance is noticed of several frusta of columns, and other blocks of stone, that were quarried at the time of the erection of St. Paul’s Cathedral, London, and which are now lying in the Isle of Portland, near the quarries from whence they were obtained. These blocks are invariably found to be covered with lichens, and, although they have been exposed to all the vicissitudes of a marine atmosphere for more than one hundred and fifty years, they still exhibit beneath the lichens their original form, even to the marks of the chisel employed upon them; whilst the stone which was taken from the same quarries, (selected no doubt with equal, if not greater care, than the blocks alluded to,) and placed in the Cathedral itself, is, in those parts which are exposed to the south and south-west winds, found, in some instances, to be fast mouldering away.

Colour is more important in the selection of a building-stone to be situated in a populous and smoky town, than for one to be placed in the open country, where all edifices become covered with lichens; for, although in such towns, those fronts which are not exposed to the prevailing winds and rains, will soon become blackened, the remainder of the building will constantly exhibit a tint depending upon the natural colour of the stone.

The chemical action of the atmosphere produces a change in the entire matter of the limestones, and in the cementing substance of sandstones, according to the amount of surface exposed to it. The particles of the stone first loosened by the action of frost are removed by powerful winds and driving rains. The buildings in this climate were generally found to suffer the greatest amount of decomposition on their south, south-west, and west fronts, arising doubtless from the prevalence of winds and rains from those quarters.

Those buildings which are highly decorated, such as the churches of the Norman and pointed styles of architecture, generally afford a more severe test of the durability of a building-stone, than the more simple and less decorated castles of the fourteenth and fifteenth centuries; because, in the former class of buildings, the stone is worked into more disadvantageous forms than in the latter, as regards exposure to the effects of the weather. Buildings in a state of ruin, from being deprived of their ordinary protection of roofing, glazing of windows, &c., afford an equally severe test of the durability of the stone employed in them.

The durability of various building-stones in particular localities was estimated by examining the condition of the neighbouring buildings constructed of them. Among sandstone buildings was noticed the remains of Ecclestone Abbey, of the thirteenth century, near Barnard Castle, constructed of a stone closely resembling that of the Stenton quarry, in the vicinity, in which the mouldings and other decorations were in excellent condition. The circular keep of Barnard Castle, apparently also built of the same material, is in fine preservation. Tintern Abbey is noticed as a sandstone edifice, that has to a considerable extent resisted decomposition. Some portions of Whitby Abbey are fast yielding to the effects of the atmosphere. The older portions of Ripon Cathedral; Rievaulx Abbey; and the Norman keep of Richmond Castle, in Yorkshire, are all examples of sandstone buildings, in tolerably fair preservation.

Of sandstone edifices in an advanced state of decomposition, are enumerated Durham Cathedral, the churches at Newcastle-upon-Tyne, Carlisle Cathedral, Kirkstall Abbey, and Fountain’s Abbey. The sandstone churches of Derby are also extremely decomposed; and the church of St. Peter, at Shaftsbury, is in such a state of decay, that some portions of the building are only prevented from falling by means of iron ties.

The choir of Southwell Church, of the twelfth century, affords an instance of the durability of a magnesio-calciferous sandstone after long exposure to the influences of the atmosphere. The Norman portions of this church are also constructed of magnesian limestone, similar to that of Bolsover Moor, and which are throughout in a perfect state, the mouldings and carved enrichments being as sharp as when first executed. The following buildings, also of magnesian limestone, are either in perfect preservation, or exhibit only slight traces of decay: the keep of Koningsburgh Castle; the church at Hemingborough, of the fifteenth century; Tickhill Church, of the same date; Huddlestone Hall, of the sixteenth century; Roche Abbey, of the thirteenth century.

The magnesian limestone buildings which were found in a more advanced state of decay, were the churches at York, and a large portion of the Minster, Howden Church, Doncaster Old Church, and buildings in other parts of the county, many of which are so much decomposed, that the mouldings, carvings, &c., are often entirely effaced.

The report speaks in high terms of the preservation of buildings constructed of oolitic and other limestones; such are Byland Abbey, of the twelfth century; Sandysfoot Castle, near Weymouth, constructed of Portland oolite in the time of Henry the Eighth; Bow-and-Arrow Castle, and the neighbouring ruins of a church of the fourteenth century, in the island of Portland.

The oolite in the vicinity of Bath does not seem to wear well.

The excellent condition of the parts which remain of Glastonbury Abbey shows the value of a shelly limestone similar to that of Doulting; whilst the stone employed in Wells Cathedral, apparently of the same kind, and not selected with equal care, is in parts decomposed. In Salisbury Cathedral, built of stone from Chilmark, we have evidence of the general durability of a siliciferous limestone; for, although the west front has somewhat yielded to the effects of the atmosphere, the excellent condition of the building generally is most striking.

The materials employed in the public buildings of Oxford, afford a marked instance both of decomposition and durability; for whilst a shelly oolite, similar to that of Taynton, which is employed in the exposed parts of the more ancient parts of the Cathedral, in Morton College Chapel, &c., is generally in a good state of preservation, a calcareous stone from Heddington, employed in nearly all the colleges, churches, and other public buildings, is in such a deplorable state of decay as, in some instances, to have caused all traces of architectural decoration to disappear, and the ashler itself to be, in many places, deeply disintegrated.

In Spofforth Castle, two materials, a magnesian limestone and a sandstone, have been employed, the former in the decorated parts, and the latter for the ashler, and although both have been equally exposed, the magnesian limestone has remained as perfect in form as when first employed, while the sandstone has suffered considerably from the effects of decomposition. In Chepstow Castle a magnesian limestone is in fine preservation, and a red sandstone rapidly decaying. A similar result was observed in Bristol Cathedral, which afforded a curious instance of the effects of using different materials; for a yellow limestone and a red sandstone have been indiscriminately employed both for the plain and the decorated parts of the building; not only is the appearance unsightly, but the architectural effect of the edifice is also much impaired by the unequal decomposition of the two materials.

After enumerating these and other examples, the Report gives the preference to the limestones, on account of their more general uniformity of tint, their comparatively homogeneous structure, and the facility and economy of their conversion to building purposes; and, of this class, preference is given to those which are most crystalline. Professor Daniell is of opinion that the nearer the magnesian limestones approach to equivalent proportions of carbonate of lime and carbonate of magnesia, the more crystalline and better they are in every respect.

It was considered that this crystalline character, together with durability, as instanced in Southwell Church, &c.; uniformity in structure; facility and economy in conversion; and advantage in colour, were all comprised in the magnesian limestone, or dolomite of Bolsover[2] Moor and its neighbourhood, and was accordingly recommended as the most fit and proper material to be employed in the New Houses of Parliament.[3] This opinion was not arrived at, nor this recommendation made, until after a very extensive series of experiments had been completed by Professors Daniell and Wheatstone upon specimens of the stones of the various quarries visited by the Commissioners. The specimens, as delivered to these gentlemen, were in the form of two-inch cubes. These experiments were of a most comprehensive kind. The composition of the stones was determined by chemical analysis:—their specific gravities; their weights after having been perfectly dried by exposure in heated air for several days; then their weights after having been immersed in water for several days so as to become saturated; the object being to ascertain the absorbent powers of the stones, which was further tested by placing them in water under the exhausted receiver of an air-pump. The stones were also subjected to the process of disintegration, invented by M. Brard, the object of which is to determine, by easy experiments, whether a building-stone will or will not resist the action of frost. Lastly, the cohesive strength of each specimen, or its resistance to pressure, was tested by the weight required to crush it. This weight was furnished by a hydrostatic press, the pump of which was one inch in diameter: one pound at the end of the pump lever produced a pressure on the surface of the cube equal to 2·53 cwt., or to 71·06 lbs. on the square inch. These trials were made with caution; the weight on the lever was successively increased by a single pound; and, in order to ensure a gradual action, a minute was allowed to elapse previous to the application of each additional weight. It was noted for each specimen the pressure at which the stone began to crack, and also the pressure at which it was crushed.

The results of all these experiments (which are stated for each stone) gave a decided preference to the Bolsover magnesian limestone, which was noticed as being remarkable for its peculiarly beautiful crystalline structure, while it was the heaviest and strongest of all the specimens, and absorbed least water. Its composition was 50 per cent. of carbonate of lime, and 40 of carbonate of magnesia; the remaining ten parts consisting chiefly of silica and alumina.

An easy Method of determining whether a Stone will resist the Action of Frost.

In the choice of a stone for building purposes, it is of the utmost importance to be able to determine, by a few prompt and easy experiments, whether the proposed stone is capable of resisting the destructive action of moisture and frost. The means of ascertaining this were difficult and uncertain, until M. Brard, several years ago, communicated his method to the Royal Academy of Sciences at Paris. This learned body having appointed a Committee of their own members to inquire into the merits of M. Brard’s process, and to make a report thereon, the united testimony of engineers, architects, masons, and builders from different parts of France, was received, and proved so favourable as to its merits and simplicity, that the Committee recommended the plan to public notice and general adoption. From their Report we select a few details, which hitherto, we believe, have not appeared in English.

When water is converted into ice an increase in bulk suddenly takes place with such amazing force that it appears to be almost irresistible. This is the force which cracks our water-bottles and ewers; splits asunder the trees of our forests; and destroys some of the stones of our buildings. But the action of frost upon stone is very gradual; it is confined to the surface, and when we see a layer of stone separated from the rock or the building, we see the result of the action of the frost during several successive winters, whereby the fragment is gradually thrust out of its perpendicular position, and at length falls. This natural process is repeated in our buildings: we rarely see squared stones split into large fragments by the action of frost except there be a cavity of some considerable size, in which a quantity of water can be collected. The usual action of the frost is at the surface, which is destroyed by the chipping off of small fragments in consequence of the adhesion of the materials of the stone being partially destroyed.

All stones absorb water in greater or less quantities, and there is no rock that does not contain some humidity. The great difference between stones which is now to be considered is in their power of resisting frost. Stones of the same kind, nay, stones from different parts of the same quarry, are acted upon very differently by frost; for, while one stone soon begins to show the destructive effects of its action, another remains uninjured during many centuries. It will, therefore, be convenient to call those stones, of whatever kind, which withstand the action of frost, resistant, and those which yield to its action, non-resistant.

M. Brard’s first idea, in order to test these resistant properties in building-stones, was, to saturate the stone with water, and then expose it to cold artificially produced; but this was found to be impracticable on a large scale, and the freezing mixtures and other means of producing cold were liable to act chemically upon the stone, and thus produce other effects than those of cold.

M. Brard was then led to compare water with those numerous solutions of the chemist, which, under certain modes of treatment, crystallize. The expansive force of salts in crystallizing is very great, and he saw no reason why water should not be regarded as a crystalline salt similar in its nature to those saline bodies which effloresce at the surfaces of stones, and in time destroy them and even reduce them to powder.

He therefore tried, in a very large number of experiments, the action upon building-stones of solutions of nitre, of common salt, of Epsom salts, of carbonate and sulphate of soda, of alum and of sulphate of iron, and found that the stones cracked and chipped, and in many cases behaved precisely in the same way as when under the influence of freezing water. In the course of these trials, sulphate of soda (Glauber’s salts) was found to be the most energetic and active, and to be the best exponent of the action of freezing water.

In order, therefore, to determine promptly if a stone be resistant or non-resistant, the following process was adopted. A saturated solution of sulphate of soda was made in cold water; the solution being put into a convenient vessel, the stone was immersed, and the solution boiled during half an hour: the stone was then taken out, and placed in a plate containing a little of the solution. It was then left in a cool apartment, in order to facilitate the efflorescence of the salt with which the stone was now impregnated. At the end of about twenty-four hours the stone was covered with a snowy efflorescence, and the liquid had disappeared either by evaporation or by absorption. The stone was then sprinkled gently with cold water until all the saline particles disappeared from the surface. After this first washing the surfaces of the stone were covered with detached grains, scales, and angular fragments, and the stone being one that was easily attacked by frost, the splitting of the surfaces was very marked. But the experiment was not yet terminated: the efflorescence was allowed to form, and the washing was repeated many times during five or six days, at the end of which time the bad qualities of the stone became fully established. The stone was finally washed in pure water; all the detached parts were collected, and by these the ultimate action of the frost upon the stone was estimated.

The behaviour of various non-resistant stones under this process was remarkable. Some were found to have deteriorated in the course of the third day; others to have entirely fallen to pieces; those of which the power of resistance was somewhat greater, held out till the fifth or sixth day; but few stones, except the hard granites, compact limestones, and white marbles, were able to stand the trial during thirty consecutive days. For all useful purposes, however, eight days suffice to test the resistant qualities of any building-stone.

The explanation of this process is very easy. The boiling solution dilates the stone and penetrates it to a certain depth, nearly in the same way that rain water by long-continued action introduces itself into stones exposed to the severity of our changeable climate. Pure water when frozen occupies a greater bulk than when fluid, and the pores or cellules of the stone not being able to accommodate themselves to the increased bulk of the water, great pressure is exerted between and among them, whereby a portion of the water is driven to the surface, and in doing so rends and detaches small portions of the stone. The same action takes place with the saline solution; it is introduced into the stone in a fluid state, from which passing into the solid it occupies a greater bulk, and a portion of it appears at the surface. The repeated washings have no other object than to allow the salt to exert its greatest amount of destructive action upon the stone. There is a striking analogy between the effect of congealed water and that of the efflorescence of salts, in the disintegration of non-resistant stones; namely, that pure water acts on the stones destructively only in a state of snowy efflorescence, which evidently proceeds from the interior to the exterior like the saline efflorescence; whilst water at the surface of the stones may freeze into hard ice without injuring them, just in the same way as salts, which may crystallize upon stones without exerting any injurious action.

The experience of several engineers, extending as it does over several years, fully proves, of a large variety of stones whose qualities were well known, that the action of M. Brard’s process and that of long-continued frost exactly coincide.

It is not the least interesting part of the inquiry to know that this process may be applied with perfect success to ascertain the solidity and resistant power of bricks, tiles, slates, and even mortar. From a mass of minute detail, we will select a few general results.

During one winter season M. Vicat composed seventy-five varieties of mortar, the difference between any two consisting in the proportion of sand and the method of slaking the lime. In the following June these mortars were exposed to the disintegrating process. Most of them were attacked in twenty-four hours; almost all of them in forty-eight hours; and all except two in three days. This gentleman also found that a mortar made ten years previously, of one hundred parts lime, which had been left exposed to the air, under cover, during a whole year, and then mixed up into a paste with fifty parts of common sand, withstood the trial admirably during seventeen days, while the best stones of the neighbourhood speedily gave way. In this case the solution was saturated while hot, which is so powerful in its effects that stones which have resisted the action of the frost for ages, soon gave way when exposed to it.

M. Vicat calculates that the effect of the sulphate of soda upon a non-resistant stone after the second day of trial equals a force somewhat greater than that exerted by a temperature of about 21° Fahrenheit, on a stone saturated with water.

The action of the process upon bricks proved that, whatever their qualities in other respects, if imperfectly burnt, they are speedily acted on. The sharp edges of the brick, and then the angles, are first rounded, and finally the brick is reduced to powder. Such is precisely the action of frost often repeated. Well-baked bricks, on the contrary, retain their colour, form, and solidity by this process, as well as under the influence of frost. Ancient Roman bricks, tiles, and mortar, and hard well-baked pottery resisted the process perfectly; as did also white statuary marble of the finest quality, while common white marble was soon attacked. In Paris, portions of buildings which had been exposed to the air during twenty years without undergoing the least alteration, were submitted to this ordeal, and the experiment agreed with observation. In one extensive series of experiments on stones from different quarries of France, the action of the salt was continued for seven days, and the results noted down; it was then continued for fourteen days, and the results compared with the preceding ones; which only served to confirm the judgment first given, for those stones which were noted as of bad quality crumbled to dust or split into fragments, while those noted for their good qualities had experienced no sensible alteration.

One of the great advantages of this process is the power it gives to the architect of choosing a hard, durable stone for those parts of the building most exposed to the action of the weather, when the funds are insufficient to admit of the whole building being so constructed. Thus the cornices, the columns, and their capitals, are struck in all directions by rain, and hail, and damp air, and are consequently far more exposed to their destructive action than the flat surface of a wall, which offers but one plane to the air.

In the course of this inquiry a very curious case arose. During the erection of a church in Paris, the architect required a good durable stone for the Corinthian capitals; and many circumstances disposed him to select it from the neighbouring quarry of the Abbaye du Val. But, on seeking the opinion of two brother architects, he was surprised to find their estimations of the stone to be totally at variance, for while one declared that he had employed it with the greatest success, another said that he had seen it yield speedily to the effects of frost. On visiting the quarry it was found that two beds of stone were being worked, an upper and a lower bed; specimens of the stone were taken from each, and on submitting them to a hot saturated solution, it was ascertained almost immediately that the upper layer furnished excellent stone, while the lower one supplied that of which the architect had so much reason to complain. But it is remarkable that the stones from the two beds had precisely the same appearance in grain, colour, and texture; so much so, that when brought into the mason’s yard it was impossible by ordinary tests to distinguish the good from the bad stone.

At the conclusion of the inquiry of the Committee, the Royal Academy of Sciences proved the high estimation in which they held this contribution of science to the useful arts, by directing to be published the following practical directions for repeating the process, for the use of architects, builders, master masons, land proprietors, and all persons engaged in building.

1. The specimens of stone are to be chosen from those parts of the quarry, where from certain observed differences in the colour, grain, and general appearance of the stone, its quality is doubtful.
2. The specimens are to be formed into two-inch cubes, carefully cut, so that the edges may be sharp.
3. Each stone is to be marked or numbered with Indian ink or scratched with a steel point; and corresponding with such mark or number a written account is to be kept as to the situation of the quarry, the exact spot whence the stone was detached, and other notes and information relating to the specimen.
4. Continue to add a quantity of sulphate of soda to rain or distilled water, until it will dissolve no more. You may be quite sure that the solution is saturated, if, after repeatedly stirring it, a little of the salt remains undissolved at the bottom of the vessel an hour or two after it has been put in.
5. This solution may be heated in almost any kind of vessel usually put on the fire, but perhaps an earthen pipkin may be most convenient. When the solution boils, put in the specimens of stone, one by one, so that all may be completely sunk in it.
6. Continue the boiling for thirty minutes. Be careful in observing this direction.
7. Take out the cubes one at a time, and hang them up by threads in such a way that they may touch nothing. Place under each specimen a vessel containing a portion of the liquid in which the stones were boiled, having first strained it to remove all dirt, dust, &c.
8. If the weather be not very damp or cold the surfaces of each stone will, in the course of twenty-four hours, become covered with little white saline needles. Plunge each stone into the vessel below it, so as to wash off these little crystals, and repeat this two or three times a day.
9. If the stone be one that will resist the action of frost, the crystals will abstract nothing from the stone, and there will be found at the bottom of the vessel neither grains, nor scales, nor fragments of stone. Be careful, in dipping the stone, not to displace the vessel.
   If, on the contrary, the stone is one that will not resist the action of frost, this will be discovered as soon as the salt appears on the surface, for the salt will chip off little particles of the stone, which will be found in the vessel beneath; the cube will soon lose its sharp edges and angles; and by about the fifth day from the first appearance of the salt, the experiment may be considered at an end.
   As soon as the salt begins to appear at the surface its deposit is assisted by dipping the stone five or six times a day into the solution.
10. In order to compare the resisting powers of two stones which are acted upon by the frost in different degrees, all that is necessary is, to collect all the fragments detached from the six faces of the cube, dry them and weigh them, and the greatest weight will indicate the stone of least resistance to the frost. Thus, if a cube of twenty-four inches of surface loses 180 grains, and a similar cube only 90 grains, the latter is evidently better adapted than the former to the purposes of building.

FOOTNOTES:

[1] Sir Humphry Davy.

[2] Bolsover is a small market town in Derbyshire, on the borders of the county of Nottingham, and about 145 miles from London.

[3] The various quarries visited by the commissioners are noticed in the fullest and fairest manner. They have stated for each quarry its name and situation; the names and addresses of the freeholder, of his agent, and of the quarryman; the name of the stone; its composition; colour; weight per cubic foot; entire depth of workable stone; description of the beds; size of blocks that can be procured; prices, per cubic foot, of block stone at the quarry; description and cost of carriage to London; cost, per cubic foot, of the stone delivered in London; cost, per foot of surface, of plain rubbed work, as compared with Portland stone; and, finally, where known or reported to have been employed in building.

Chapter III.
THE WALLS. BRICKS AND BRICK-WORK.

We now come to that material which is, in England, a more important agent than stone in the construction of dwelling-houses; namely, bricks made from clay. There were three millions and a half of houses in Great Britain in the year 1841; and there can be no doubt that of this number those which were built of brick constituted a vast majority. It is only in a few particular districts that stone is a more available material for houses than bricks. In other countries, too, as well as our own, the arts of brick-making and bricklaying are carried on more extensively than the operations of the stone-mason.

Bricks and Brick-work in Early Times.

It has been observed that “the art of making bricks is so simple, that it must have been practised in the earliest ages of the world; probably before mankind had discovered the method of fashioning stones to suit the purposes of building.” It is stated in the Book of Genesis that burnt bricks were employed in the construction of the Tower of Babel. Now, as this structure appears to have been raised about four hundred years after the Deluge, it is scarcely an exaggeration to say that the art of making bricks was invented almost as soon as men began to build. Bricks seem to have been in common use in Egypt while the Israelites were in subjection to that nation; for the task assigned them was the making of brick, and we are informed in the Book of Exodus, that the Israelites built two Egyptian cities. No particulars are given in Scripture of the method of making bricks; but as straw was one of the ingredients, and as very little rain falls in Egypt, it is probable that their bricks were not burned, but merely baked by the heat of the sun. The same mode of baking bricks seems still to be practised in the East. The ruins of the tower near Bagdad are formed of unburnt bricks. The art of brick-making was carried to considerable perfection among the Greeks. Pliny states that they made use of bricks of three sizes, distinguished by the following names: didoron, or six inches long; tetradoron, or twelve inches long; and pentadoron, or fifteen inches long. That the Romans excelled in the art of making bricks there is the amplest evidence, since brick structures raised at Rome seventeen hundred years ago, still remain nearly as entire as when first built.

A remarkable kind of floating brick, used by the ancients, has been made the subject of investigation in modern times, with a view to the suggestion of improvements in the making of bricks for particular purposes. Pliny states that at various places in Spain, in Asia Minor, and elsewhere, bricks were made which, besides possessing considerable strength and a remarkable power of enduring heat, were yet of such small specific gravity, that they floated on the surface of water. Like many of the arts of the ancients, the method of making these bricks, as well as the material of which they were made, were forgotten for many ages. About the year 1790, however, an Italian, named Fabbroni, turned his attention to the subject, and after various experiments on minerals of small specific gravity, he came to the conclusion that these bricks must have been composed of a substance called “mountain-meal;” or, at least, he found that he could make of this substance bricks which appeared to agree in every respect with those described by the ancients. This mountain-meal is an earth composed of flint, magnesia, clay, lime, iron, and water, in certain definite proportions. The bricks which Fabbroni formed of this material had the property of floating in water; they could not be fused by any ordinary degree of heat; and so low was their conducting power, that while one end of the brick was red-hot, the other could be held in the hand without the smallest inconvenience. It has been supposed that a peculiar kind of earth, found in some parts of Cornwall is the same as that with which Fabbroni experimented on in Italy, and that both are analogous to the kind of which the ancients made their floating bricks. Proceeding on this supposition, it has been proposed to make such bricks for the construction of floating houses upon ornamental waters. At present such structures can be made only of timber; and, however the owner may decorate them, they have always a flimsy and unsubstantial appearance, and they are soon injured by the weather. If, however, a platform of good timber were employed as the base of the whole, and the weight so contrived as to keep this platform constantly under water, it would last a long time. The upper part of the structure formed of the floating bricks, might have all the appearance, and, indeed, all the stability of a brick house upon land; for this description of brick resists the influence of the atmosphere as well as the action of fire; and although it is not absolutely so strong as the heavy brick in common use, it is far more so in proportion to its specific gravity. We do not know whether these conjectures have yet been put to the test.

That the early inhabitants of many countries in the eastern and central parts of Asia were acquainted with the use of bricks in building, we have abundant proof from the descriptions of intelligent travellers; and there are even grounds for attributing to them a very high degree of mechanical skill both in the making of the bricks and the formation of brick walls. Dr. Kennedy, in his Campaign of the Indus, says:—“Nothing I have ever seen has at all equalled the perfection of the early brick-making, which is shown in the bricks to be found in these ruins [ancient tombs near Tatta]: the most beautifully chiselled stone could not surpass the sharpness of edge, and angle, and accuracy of form; whilst the substance was so perfectly homogeneous and skilfully burned, that each brick had a metallic ring, and fractured with a clear surface, like breaking freestone. I will not question the possibility of manufacturing such bricks in England, but I much doubt whether such perfect work has ever been attempted.”

Making Bricks by Hand.

In the mechanical arrangements for making bricks two very different systems are adopted; the one handicraft, and the other by machinery. The former has always been and still is far more extensively adopted than the latter.

In the selection of materials for brick-making, a brown loamy clay, that is, clay which contains a small quantity of calcareous matter, is considered best for ordinary bricks, but the ingredients vary according to the purposes for which the brick is required; and every one must have remarked the difference in colour between the light yellow marl stocks, as they are called, employed in the facing of houses of the better kind, and the dark red brick used in Lancashire and other northern counties. The colour also varies with the proportion of ashes or sand employed in the mixture, and with the degree of heat they are subjected to in drying. The general process is, however, much the same everywhere; and we shall describe that used in England, where bricks are always burnt.

The proper kind of clay being found, the top vegetable mould is removed, and the earth dug and turned over to expose it as much as possible to atmospheric action, and for this purpose it is left for the winter. In spring, a quantity of fine ashes, varying in proportion to the clay from one-fourth to a fifth, according to the stiffness of the latter, is added by degrees, and well incorporated by digging and raking, water being poured on to render the mass soft. When the union is effected, the clay is carried in barrows to a rude mill, erected near the shed, in which the brickmaker works.

This mill consists usually of a vat, or circular vessel, fixed on a timber frame; an upright iron axle is placed in the centre of the vat, and carries some iron plates, or rakes with teeth, to stir up the soft clay when placed in the mill: this axle is turned round by a horse harnessed to a horizontal shaft which proceeds from the axle. The clay being put into the vat, the rakes or knives complete the incorporation of the ashes, and thoroughly temper the whole mass, which is gradually squeezed out through a hole in the bottom of the vat.

A better kind of mill is used in tempering the material for the better bricks; it only differs, however, in being larger. An iron harrow loaded with weights is dragged round in a circular pit lined with brick-work. The clay in this case is diluted with water sufficiently to allow of the stones sinking to the bottom; and the fluid is drawn off into pits, where it is left to settle and thicken, to the proper consistence.

The prepared clay is first separated into masses, each large enough to make a brick, by the feeder, or assistant, who sands the pieces ready for the moulder; the mould is an open rectangular box, the four sides of which are made to separate from the bottom, to allow of the brick being turned out. The bottom is now made with a lump raised on it, by which a slight depression is formed on one side of the brick, to admit a mass of the mortar being received and detained in it when the wall is built.

The moulder takes the piece of clay prepared for him, and dashing each into the mould so as to cause it to fill it, removes the superfluous quantity by means of a flat piece of wood which he draws across the open side of the mould; this strike is kept in a bowl of water to wet it, and prevent the adhesion to it of the clay. The man then lifts off the sides of the mould, and deposits the brick on a flat pallet-board, and this is removed by a boy who ranges the bricks on a lattice frame set sloping on the barrow in which they are to be taken to the field to dry; fine sand is strewed on the frame and over the bricks, to prevent their adhering together.

The bricks are taken to the field, and piled in long lines called hacks. This is a nice operation, as the soft bricks, if handled roughly, would become twisted, and rendered useless; the bottom course of bricks is raised a few inches to keep it from the wet; and the ground is prepared to receive them by being covered with dry brick-rubbish or ashes, and raked smooth. The bricks are set alternately in rows lengthwise and crosswise, with intervals between them of an inch or more, to allow a thorough circulation of air: the hack, when raised about a yard high, is covered over with straw to throw off the rain.

If the weather be favourable, ten or twelve days are enough to dry the bricks in the hacks sufficiently to prepare them for burning, but they should be thoroughly dry, or the subsequent process will fail.

Ordinary bricks for building are burnt in clamps, which are large oblong masses, built up of the unburnt bricks, laid regularly in layers, with large flues or passages at intervals, in which ashes, cinders, coal, and brush-wood are laid; layers of ashes are strewed over those of the bricks. The object is, that the fire, when the fuel is ignited, may penetrate every part of the mass, and bake every brick equally; even the ashes mixed up in the clay are intended to be partly burnt by the heat. In clamps well constructed the outside is coated with clay or plaster to keep in the heat, and when the fuel is thoroughly lighted, the external apertures should be stopped up.

The clamp when completed contains from 100,000 to 500,000 bricks. The fire will continue burning about three weeks, if the pile has been well constructed: when all smoke ceases to rise, the clamp is taken down when cold, and the bricks sorted; for, even with the utmost care, it must happen that the bricks are not all equally burnt. The best are those in the centre. The under-burnt ones are reserved to be rebuilt into a new clamp for further baking, and those which are over-done, and have run together by partial vitrification, are sold at a cheap rate for making foundations for houses, roads, &c.

The better or peculiar kinds of bricks, as well as tiles of all kinds, are burnt in kilns instead of clamps. These kilns, though of a peculiar form, according to the purpose to which they are applied, yet do not differ in principle from the lime-kiln, &c. In the kiln, the fire is not intermixed with the bricks, but is applied beneath; nor are ashes mingled with the clay of which kiln-burnt bricks are made.

As the general principles are the same in making tiles and bricks, we shall class all these coarse pottery-works together here, in an enumeration of the most important kinds used in Britain.

Place-Bricks are the worst of the clamp-burnt stocks, and are used for common walls, and the poorest kinds of work; they are soft and unequally burnt; they sell from 20s. to 30s. a thousand.

Stock-Bricks are those from the centre of the clamp, and are regularly burnt, of an equally hard texture, and even colour; they are used for good work of all kinds; the price varies from 30s. to 40s. a thousand.

Malm-Stocks are clamp bricks, but made with more care from clay to which ooze, chalk, or marl is added; and the whole carefully tempered; they are of a fine clear yellow colour, and are used for facing the walls of good houses, and for making arches over doors and windows in general, where they are to be seen. The softest kind are called cutters, from their admitting of being cut, or trimmed, with the trowel with nicety. The prices of these bricks vary greatly.

Fire-Bricks are made of a peculiar kind of clay, found in perfection at Windsor, Stourbridge, and parts of Wales, whence the varieties derive their names. They are formed from the clay without any admixture of ashes, and are always kiln-burnt. They vary in size, and are used for building furnaces, ovens, boilers, &c.

Pan-Tiles are tiles, the cross section of which may be represented thus.

They are used for roofing outhouses, stables, &c., the edges of one row overlapping those of another next it, and they are always set in mortar: the end of the tile is formed with a projecting knob or fillet, by means of which the tile is hooked on to the batten or lath. These tiles are much larger than the Plain-Tiles, which are used in roofing dwellings, &c.; they are flat, as the name indicates, and are fixed to the laths of the roof by wooden pegs, two holes being left in the tile for that purpose. Foot and ten-inch tiles are thick square tiles of those dimensions, used for paving, hearths, &c., or for coping walls. All tiles are burnt in a kiln.

Bricks made in Great Britain are charged with a duty, and as it constitutes an important item in the revenue, the manufacture is laid under strict surveillance by the Excise. The duty on tiles was repealed in the year 1833. Bricks can only be made at certain seasons, in certain quantities, and even the screen through which the ashes are sifted, to be mingled with the clay, must be made of wire of a certain mesh. Bricks made larger than the standard measure of 8½ inches long, 4 wide, and 2½ thick, pay a higher duty than the common ones; if the bricks are smaller than the proper size, the maker is fined heavily. No duty is charged upon bricks made in Ireland.

About 1500 millions of bricks, 42 millions of plain, 23 millions pan, and 6 millions of other tiles, are made annually in Britain. A good moulder can make from 5000 to 6000 bricks in a day, from five A.M. to eight P.M.

Within the present century, the annual use of bricks in Great Britain has more than doubled, owing to the increase of manufactories, and to the construction of railroads and other public works.

Making Bricks by Machinery.

Within the last few years the making of bricks and tiles by machinery has occupied much attention. A large number of patents has been taken out for contrivances having this object in view. In some cases the patentee has directed his attention chiefly to the preparation of bricks for houses; while in others the making of tiles for draining has been the chief object. A description of one or two of these contrivances will give an idea of the general character of the whole.

The Marquis of Tweeddale, having his attention drawn to the importance of employing draining tiles in agriculture, directed his talents to the invention of a machine which should make them so quickly as to enable them to be sold at a low price. After many attempts, he perfected a machine which worked out this object, and at the same time possessed all the facilities for making common bricks. The machine is not constructed on the principle of imitating the manual operation, by forming the bricks in moulds; but it arrives at the same end in a different and remarkable manner. The principle adopted is, to form and protrude, by mechanical means, a continuous fillet of clay, of the proper width and thickness for a brick, and to stop this act of protrusion for a moment, whilst a length of the fillet equal to that of a brick is cut off. This is effected by the following mechanical arrangements:—Two vertical roller-wheels, one of them being placed over the other, and having an interval between them equal to the thickness of the intended bricks or tiles, are made to revolve in contrary directions; consequently they draw between them the clay with which they are fed on the one side (either by hand or by any mechanical contrivance), and deliver it on the other in a highly compressed state, and in the form of a straight, smooth, and even fillet of the width of the rollers. To provide for the squareness and smoothness of the sides of the fillet, the sides of the aperture through which the clay passes are made square and neat, so as to prevent the clay from spreading out laterally. The clay is supported in a horizontal position whilst delivered to and received from the rollers, upon a short endless band on each side revolving on rollers rather close together; and in order to facilitate this object the rollers themselves have bands, which are prolonged in the direction of the endless bands in such a manner as to meet them, and form one horizontal line of support. These bands are made of fustian, the nap of which prevents the adhesion of the clay. The rollers are so acted on by the working power that they protrude a length of clay equal to the required length of the brick or tile, and then stopping, they allow time for a straight stretched wire to descend and cut off the brick or tile, after which the motion between the rollers is resumed, until another length is protruded, and so on continuously. The fillet of clay is double the width for a brick, and a wire is kept constantly stretched in the middle of its path, dividing it into two fillets, so that two bricks are cut off at once. Two boys are sufficient to remove the bricks as fast as they are produced, which is at the rate of from fifteen to eighteen hundred in an hour. The consistence of the clay is so much stiffer than that used for hand-made bricks, that only half the time is required in the drying. From there being so little water in the clay, and from its undergoing so much compression, the bricks produced are remarkably dense and strong, weighing half as much again as the ordinary brick, and absorbing only one-seventh as much water.

Many machines have been contrived, having for their object the formation of bricks on a principle somewhat analogous. Another class of machines have effected the desired end in a different way,—viz., by forming each brick separately in a mould. A slight description of one machine of this kind will illustrate all the others. The main part of the machine is a horizontal wheel of large diameter. Round the periphery of this wheel is a series of moulds, the exact size and shape for bricks, placed nearly close together. Each mould has a loose bottom, incapable of falling below the mould, but capable of rising to its upper edge. The clay for the bricks, being properly prepared in vessels at one side of the wheel, is made to fall into one of the moulds, and the superfluous quantity is scraped off by a flat edge which passes over the mould. The wheel rotates, and in its movement it passes over a circular inclined plane, so constructed as to lift the bottom of the mould up, so as to protrude the newly-made brick above the mould, where it can be conveniently taken off by the hand. All the different moulds, perhaps thirty or forty in number, are at any given instant in different conditions as to their quota of clay; one is receiving the clay, another is having the superfluous clay scraped off, another has travelled so far round as to have the brick lifted halfway out of it, another presents the brick wholly out of the mould, ready to be taken off, while the others are travelling on empty to receive a new supply of clay, all the moveable bottoms gradually sinking to their proper position as the wheel proceeds, so that one rotation of the wheel carries each mould through all its different stages of position.

The Processes of Bricklaying.

When we consider that a wall forty or fifty feet high, and not more than two feet thick at the bottom, and fourteen or fifteen inches thick at the top, is constructed of such small bodies as bricks, we may well suppose that considerable nicety in workmanship must be requisite to give stability to such a structure. The uniformity in size in the bricks themselves, arising from their being copies of one mould, is obviously the first condition that tends to the object; the next is, that they should be put together in such a way as to cause them mutually to adhere, independently of the tenacity of the mortar employed; and lastly, the bricks must be set with great attention, that their surfaces may be perfectly parallel and perpendicular to the direction of gravity, for otherwise the wall composed of them, instead of being truly perpendicular, would lean over on one side and fall. We shall enter into some particulars on these points, but first we must describe the tools and materials used in Bricklaying.

The trowel is the first and most indispensable of these tools. It is a thin, flat, lozenge-shaped blade of steel, fixed into a handle. It is with the trowel the workman takes up and spreads the layer of mortar put between each brick, and with it he also cuts the bricks so as to fit into any corner, or to adapt them to some particular form; and to enable it to cut, or rather chip, such a hard substance as burnt clay, and yet not break, it is necessary that the blade should be of well-tempered hard steel. The square and level are made of wooden rules put together; the first at a true right angle, to enable the bricklayer to set out his walls correctly perpendicular to each other,—the second is framed like a ⟂, with a plummet hanging in a slit in the upright piece; now, as the two rules are correctly perpendicular to each other, it is clear that when the first is set by means of the plumb-line perpendicular to the horizon, the other will be truly horizontal. By means of this important instrument, the workman guides his work, so that the wall he is building shall be upright, and the courses of bricks composing it horizontal. By means of this important instrument, the workman guides his work, so that the wall he is building shall be upright, and the courses of bricks composing it horizontal.

Mortar is the name given to the composition with which the bricks are put together. Good mortar should be made of newly-burnt quicklime from grey limestone, and of clean river-sand, in the proportions of one-third lime to two-thirds sand. The lime is slaked by pouring a little clean water on it, and when it falls to powder by the chemical action, the sand is added gradually, and the whole well mixed up with a spade, more water being used till the mass is of the proper consistence for spreading easily. As the adhesion of the bricks depends on the mortar being applied before it begins to set or harden, it should not be mixed till it is to be used. When these simple precautions are attended to, the mortar becomes in time as hard as stone, and the brick-work constructed with it is nearly as indestructible. It was by taking this care with their materials that our forefathers built walls that have stood uninjured for centuries. In some of the cheap common buildings of the present day, mortar is too often made from lime which has been so long from the kiln, that it is nearly reconverted into a hydrate, and has lost the chemical quality which renders it valuable; the sand, too, is taken from the road with all its impurities, and the water from the nearest kennel. With such materials a mass of mortar is made, and suffered to stand for several days before it is used; the consequence is, that such buildings are neither safe nor durable.

The mortar is made up by an assistant, called a bricklayers’ labourer, and is taken by him to the spot where the workman wants it in what is called a hod: this utensil, which consists of three sides of a rectangular box fixed edgeways at the end of a long handle, is expressly contrived to be carried on the man’s shoulder, and leave his hands disengaged, to enable him thus loaded to ascend and descend a long ladder; the hod being held standing upright on the handle, the labourer can put bricks into it with his right hand, or another assistant fills it with mortar.

The manner in which the bricks are arranged in the work, is termed bond, and is of different kinds, according to the thickness of the wall, and the purposes for which it is intended. The bond most generally used is termed Flemish, in which the bricks are laid alternately lengthwise and across the thickness of the wall, the broadest side of the brick being laid horizontal, and never edgeways, in building walls of every thickness. It was formerly usual to lay a whole course of bricks lengthwise, and that above it across; this disposition may be seen in old walls, and was termed English-bond. In every kind of bond, the joints of the bricks of one course are always made to fall over a brick in that beneath, or so that one joint may never be immediately over another.

The site of a wall, or the walls of a building, being set out or marked on the ground, a trench is dug in the earth for the foundations, the width and depth being determined on from the thickness and height of the superstructure, and from the nature of the soil. If this be loose or soft, and the edifice be an important one, it is often necessary to drive piles into the bottom of the trench, and lay a course of oak planking on the tops of these timbers, to form a firm foundation for the wall; but if the nature of the ground do not require such precautions, it is only necessary to level the bottom of the trench carefully, as on this the stability of the wall will entirely depend. A course of bricks is then laid dry on the earth, forming a band twice the width of the lowermost thickness of the wall to be built. This and the subsequent courses of the foundations should be constructed of the best bricks; but unfortunately in common houses this obvious requisite is entirely neglected. When this course is laid, thin mortar, or mortar almost fluid and having but little sand in it, is poured over the bricks, so as to flow into the joints and bind them together by hardening: a second course is then laid on the first, only narrower in width, and each subsequent course diminishes in the same regular manner on each side, till the width is reduced to the thickness at which it is proposed that the lower part of the wall should be built. A cross section of these foundations thus constructed would present the outline of a truncated pyramid, diminishing by regular sets-off or steps; this part of a wall is called the footings. For garden walls, or such as have no weight to carry, the footings need not be made of so many courses, nor so broad, but every wall must have two courses at least for a foundation.

The bricklayer makes use of a string stretched between two pins, to enable him to keep his work straight; and he lays the outermost bricks, those forming the face of the wall, carefully by this guide, setting each brick alternately lengthwise and transversely, and spreading a layer of mortar on the brick beneath, to form a bed for the new one to lie on, and also a layer between each upright joint. It is usual only to lay the outer bricks in this manner, and to fill up the interstices of those forming the interior of the wall by pouring mortar on each course previously laid dry with sufficient interval between them. The workman as he proceeds, repeatedly makes use of his level and square; by the former, he examines whether the face of his wall, and all the corners, or arrises, are correctly perpendicular, and whether the courses of bricks are laid horizontal.

Apertures, such as windows or doors which are to be formed in the wall, are marked out on the wall when the work is built up to the height where they are to commence; in carrying up the piers between these windows, it will frequently happen that the width of the pier is not precisely commensurate with a certain number of bricks or half-bricks, but that a brick must be cut to bring the work to the correct dimensions. This smaller piece is termed a closure, and is usually placed within a brick or two of the arris of the window or door, and preserves its place for the whole height of the pier.

The thickness of brick walls is described by the number of bricks’ length they contain in that direction: thus a nine-inch wall is one-brick thick; a brick-and-a-half wall is fourteen inches; a two-brick wall is eighteen inches thick, and so on. The walls of small houses are often only one brick thick, even when they are two stories high; but usually a wall to be steady should decrease in thickness half a brick at least every story, and for a large substantial building of four or five stories, the main walls should be two-and-a-half bricks at least on the basement story, and one-and-a-half at the top; but of course the size of the apartments, or, in fact, the area of wall which is to remain without any lateral support, must govern the strength of it, as well as the total height to which it is to be raised.

When the wall is raised as high as the tops of the windows, &c., which were left in it, these apertures must have arches turned over them, to support the brick-work above. This leads us to consider the different modes of constructing brick arches. When the width of the opening is not above three or four feet, the arch over it is frequently straight in its outline, or but slightly curved in the intrado or lower line. The bricks which are to form the arch are rubbed down on a board till they are brought to the proper wedge form. A piece of wood for a centering is supported in the opening by upright slips: the upper side of this centering is, of course, cut to the true camber or curve the intrado of the arch is to have: the bricks are set upright on this centre, and alternately, so as to break the joints. The face of the arch, which is seen in the street over the windows and doors, is constructed of the best bricks, carefully cut to a mould and set in putty, or in thin mortar made of lime only: the rest of the arch behind this face is less carefully constructed, and the bricks are often not cut at all, but made to form an arch by the intervening layer of mortar being spread unequally thick, or in a wedge shape. When, however, a large arch is to be built of bricks, these are cut to the proper level to form the wedge-shaped voussoirs. The construction of groined arches in brick-work is the most difficult operation in the trade. Each brick that forms the arris or intersection of the cross vaults requires to be cut to a true form given by a drawing made to the full size on a board. Another perhaps still more delicate piece of workmanship for a bricklayer to execute is an oblique arch, such as are often seen in the bridges over railroads and canals, which cut established roadways obliquely. These arches are portions of a cylinder, but the ends of the cylinder, instead of being perpendicular to the axis, are oblique to it, and this requires that the courses of bricks composing the arch shall also not be parallel to the axis, and therefore not in straight lines: hence, every brick has to be cut or rubbed to a wedge form in two directions, and great nicety in this and the subsequent operations are requisite in these structures.

Formerly columns, pilasters, cornices, niches, and similar architectural embellishments, were constructed in brick-work, but stone has now superseded brick for all embellishments; and the bricklayer’s greatest skill is only required in the construction of arches, or occasionally building a circular wall. The best specimens of elaborate brick-work of the old school may be seen at the conservatory of Kensington Palace, at Burlington House, and many other edifices of the time of William and Mary, and Queen Anne, throughout the country. The series of arches extending for nearly four miles on the Greenwich Railway, and those for nearly an equal distance on the Blackwall Railway, are perhaps among the best and most imposing specimens of modern brick-work, and afford, in many places, beautiful examples of the oblique arch. There are brick arches of a large span at each end of the new London and Waterloo bridges.

Brick-work is measured by the rod, which is a superficial area of sixteen and a half feet each side, or 272 square feet, at a thickness of one-and-a-half brick, and all plain wall-work is reduced to this standard for valuation. A rod of brick-work contains 4500 bricks, and together with the mortar required to build it, weighs about 15 tons 8 cwt. It differs in value from 10l. to 15l., according to circumstances.

Besides building walls, bricklayers are employed to tile roofs, set coppers, pave stables, &c., build drains, and, in short, on all occasions where bricks or tiles are the materials used.

Defects of Modern Brick Houses.

A writer in the Encyclopædia Britannica endeavours, with much ingenuity, to show that the quality of English bricks and the system of bricklaying are very much influenced by the customary leasehold tenure of land. His remarks are as follow:—“Brick-making has been carried to great perfection by the Dutch, who have long been in the habit of forming their floors, and even, in some cases, of paving their streets with bricks. And it is remarkable how long their bricks will continue unimpaired in such situations. Though brick-making has long been carried on in England, and especially in the neighbourhood of London, upon a very great scale, and though the process upon the whole is conducted in this country with very considerable skill, yet it must be acknowledged that English bricks are by no means so durable as Dutch bricks. We are disposed to ascribe this inferiority not so much to the nature of the materials employed in the manufacture of English bricks, as to the mode most frequently adopted in London of building houses. Few of the London houses, comparatively speaking, are freeholds. Most of them are built upon ground let for a lease of a certain number of years, which seldom exceeds ninety-nine years. After the expiration of this period the house becomes the property of the landlord who let the ground. Thus it becomes the interest of the builder to construct the house so that it shall last only as long as the lease. Hence the goodness of the bricks becomes only a secondary object. Their cheapness is the principal point. The object, therefore, of the brickmaker is not to furnish durable bricks, but to make them at as cheap a rate as possible. Accordingly, the saving of manual labour and of fuel has been carried by the makers of London bricks to very great lengths. We cannot but consider this mode of proceeding as very objectionable, and as entailing a much heavier expense upon London than would have been incurred had twice the original price been laid out upon the bricks when they were first used, and had the houses been constructed to last a thousand instead of a hundred years. No doubt certain advantages attend these ephemeral structures. The inhabitants are enabled, once every century, to suit their houses to the prevailing taste of the day; and thus there are no (few?) antiquated houses in London. But as the increase of the price of all the materials of building has more than kept pace with the increase of the wealth of individuals, it is to be questioned whether the houses are always improved when they are pulled down and rebuilt.”

Chapter IV.
THE ROOF. SLATES, AND OTHER ROOF COVERINGS.

We might, perhaps, under the designation of “Slates and Slating,” have included the operations usually understood to appertain to the construction of a roof. But modern improvements have rendered such a designation incomplete. We cannot now properly understand the mode of roofing houses without referring to many other substances besides slate.

Slate-Quarries.

Slate is the popular name for a variety of rocks which are sufficiently stratified in their structure to allow of their being cleaved into thin plates, a property which renders them valuable for a variety of purposes. Slate has superseded the use of lead for covering roofs, even of the largest buildings: from its lightness it is preferable to tile, but the latter being cheaper, in flat countries which do not contain rocks, but which yield brick-clay, slate in such localities is only used on the better class of houses. In mountainous countries, a slaty rock, which admits of being split thin, though not so much as clay slate, is used under the name of shingle.

Besides being employed for roofing, slate is used in large slabs to form cisterns, for shelves in dairies, for pavement, and similar purposes, for which its great strength and durability, coolness, and the ease with which it can be cleaned, owing to its non-absorbing property, adapt it. The latter quality renders it also of great value as a cheap substitute for paper, in the business of education; the system of teaching in large classes in National and Sunday-schools would be greatly fettered but for the use of slates.

The principal slate-quarries in Britain are in Wales, Cumberland, and various parts of Scotland; the mode of working them is generally the same. The rock is got out in tabular masses by means of large wedges, and is then subdivided by smaller to the requisite thinness; the pieces are roughly squared by a pick, or axe, and sorted, according to their sizes, for roofing. The largest called imperial, are about three and a half feet long, and two and a half wide; the smallest average half those dimensions. When wanted for paving, &c., the large blocks are sawn into thinner slabs, in the same manner as stone or marble is.

A few words respecting the position and working of some of the slate-quarries may be appropriate, as illustrating the nature of this remarkable geological formation.

A Slate-Quarry.

The most extensive slate-quarries in Great Britain are those near Bangor, in Wales, from which slate is shipped to all parts of the world. The slate occupies the greater part of the distance from Snowdon to the Menai Straits. Upwards of two thousand men are employed in these quarries; and the proprietor is said to gain from thirty to forty thousand pounds per annum by them. Although this one is the largest, yet there is one in Cumberland in which the slate is found more remarkably situated. This is Hourston Crag, a mountain near Buttermere Lake, about two thousand feet above the level of the lake, and nearly perpendicular. On account of the difficulty of access, the workmen take their provisions for the week, and sleep in temporary huts on the summit. During the winter months they are generally involved in clouds, and not unfrequently blocked up by the snow. The slate is conveyed on sledges down a zigzag path cut in the rock, one man attending to prevent the acceleration of the descent. When the slate is emptied at the bottom the sledge is carried back on the man’s shoulders to the summit.

Notwithstanding the value of slate, few quarries are worked to a very great depth, or have subterranean galleries like mines. There is one, however, near Charleville, in France, which is an exception to this rule. The mouth of the mine is near the summit of a hill; the bed inclines forty degrees to the horizon, and is about sixty feet in thickness, but the extent and depth are unknown. It has been worked by a principal gallery to the depth of four hundred feet, and many lateral galleries have also been driven, extending about two hundred feet on the side of the main gallery. Twenty-six ladders are so placed as to give passage to the workmen and carriage for the slate. Of the sixty feet which constitutes the thickness of the bed of slate, about forty are good slate, the rest being mixed with quartz. The slate is cut into blocks of about two hundred pounds each, called faix; each workman, in his turn, carrying them on his back to the very mouth of the pit, mounting all or part of the twenty-six ladders, according to the depth of the bed where he may be working. When brought to the surface, these blocks are split into thick tables called repartons, by means of a chisel and mallet; and these repartons are divided by similar means into roofing-slates.

Another remarkable slate-quarry in France, is situated near Angers. The bed of slate extends for a space of two leagues, passing under the town of Angers, which is in great part built of slate; those blocks which are the least divisible being employed in masonry. The quarries actually explored are all in the same line, from west to east, as well as the ancient pits, the bed of the best roof-slate rising to the surface in this direction. Immediately under the vegetable earth is found a brittle kind of slate, which, to a depth of four or five feet, splits into rhomboidal fragments. A little lower is the building-stone, which is a finer but scarcely divisible slate, and is employed in the construction of houses, after it has been sufficiently hardened by exposure to the air. At fourteen or fifteen feet from the surface is found the good slate, which has been quarried to the perpendicular depth of three hundred feet, without its lower limit being attained. The interior structure of the slaty mass is divided by many veins or seams of calcareous spar and quartz, fifteen or sixteen feet in length, by two feet thick; these veins are parallel, and proceed regularly from west to east in a position rising seventy degrees to the south; they are intersected by other veins at intervals of a similar kind, but whose rise is seventy degrees north; so that when the two series meet, they form rhombs or half-rhombs. All the layers or laminæ of slate have a direction similar to those of the veins of quartz, so that the whole mass becomes divided into immense parallel rhomboids. The slate is extracted in blocks of a determinate size, which are then divided into leaves for roof-slates. When the blocks have been drawn from the quarry, if they are left exposed to the sun or the open air, they lose what is called the quarry-water, and then become hard and untractable, and can only be employed as building-stone. Frost produces a singular effect on these blocks; while frozen, they may be broken with more ease than before; but if thawed rather quickly, they become no longer divisible; yet this quality may be restored by exposing them once more to the frost.

The Process of Slating.

When the blocks of slate for roofing have been split, and the laminæ roughly squared, they are sorted, according to their size and quality, and are brought to market under the quaint names of Imperial slates, Duchesses, Countesses, &c., the first variety being the largest. The best roofing-slates come from the celebrated vale of Festiniog.

Slates are laid on battens, or thin narrow deal boards, which are nailed horizontally on the common rafters of the roof, at equal distances apart, which distance is governed by the size of the slate to be employed. An entire board is nailed along the lowest edge of the roof to receive the lead of the gutters, which are first laid, and then the lowest course of slates are nailed and pinned down to the lowermost batten; so that two-thirds the length of the slate, at least, shall lie over the lead. The next course of slates is then fixed, so that every slate shall overlap two-thirds the depth of the course below it, every slate being also laid over the joint, between two slates of that undercourse. By this construction the rain that runs through the joint between any two slates is kept from penetrating into the roof by being received on the surface of the slate beneath that joint; and the bottom course of slates is double, to continue the same principle down to the lead gutter.

The slates are fixed to the battens by two copper nails and a wooden pin when the work is well executed; holes being picked through each slate for the nails to pass through.

Paper Roofs.

Although, as intimated in a former page, in covering our imaginary dwelling with tiles or slates, we may seem to have done all that is necessary in respect to “roofing,” yet we should leave our subject only half treated if we were to omit mention of other contrivances which have been partially acted on; such as the use of paper, of asphaltum, and various other substances.

About thirty years ago, Mr. Loudon published a pamphlet, in which he described the mode of preparing paper for roofs, and discussed the various arguments for and against its adoption. His description had immediate relation to a series of paper roofs in a large farm at Tew Lodge, in Oxfordshire, and comprised the following among other particulars.

Paper roofs may be made very flat, being raised no higher than just sufficient for throwing off the water. Instead of tile, slate, or thatch, they are covered with paper, prepared by immersion in a mixture of tar and pitch. In the first place, pieces of wood called “couples,” are laid across the walls of the building, rising two inches and a half to the foot to obtain a drainage obliquity; these couples vary from two or three to six inches square, according to the size of the roof. On the couples are placed horizontal rafters, about two inches square; the distance between the couples being from five to eight feet, and between the rafters about eighteen inches; the couples are nailed to the wall plate, and the rafters to the couples. At Tew Lodge, the rafters used were young larch-trees, sawn up the middle, cut to the proper lengths, and prepared so that the upper surface should be level. On the rafters are placed thin boards, from a half to five-eighths of an inch in thickness; these boards are nailed to the rafters, not horizontally as for slating, but in a direction from the eaves to the ridge of the roof. In some cases substitutes for thin boards may be used; such as close copse-wood hurdles, plastered over; or common plaster-laths.

The paper employed may be any common, coarse, strong kind; that kind used by button-makers being favourable for the purpose. It is prepared as follows: a boiler or cauldron, three feet wide by two deep, placed over a fire, is filled to within six inches of the top with tar and pitch, in the proportion of three parts of the former to one of the latter; the fire being applied and the mixture made to boil, the paper is immersed in it one sheet at a time, and then laid in a stack or pile with such a slope as to allow it to drain, a little grease of any kind being placed between the sheets to prevent their adhering; and when dry the paper is similarly treated a second time. The paper thus prepared is then nailed down to the roof. The workman begins at the eaves, and allows three inches for being turned down and nailed underneath the end of the board, which boards project an inch over the first rafter. If the paper be common, coarse, wrapping paper, it is laid on much the same as slate, so that when finished it will remain in double thickness all over the roof; but if thicker paper be employed, it is only made to overlap about three inches in each layer. Every sheet is fixed down with four nails about an inch in length, having broad flat heads.

On the paper thus fixed is laid a composition consisting of two parts of tar to one of pitch, thickened to the consistence of paste, with equal parts of whiting and powdered charcoal. The composition being well boiled and kept constantly stirred, it is spread over the roof with a hempen mop as quickly as possible on account of the speedy cooling. When properly laid on and dried, the composition totally conceals the joints of the paper, and forms a smooth and glossy black covering an eighth of an inch in thickness. Sometimes, while the composition is yet wet, sand, dust, or ashes are strewed on, to increase the substance, and shield the composition from the action of the sun.

Mr. Loudon enumerates as the advantages of this roof—economy, durability, and elegance. The economy is shown by the circumstance that, on account of the lightness of the paper, less massive walls and timbers are required than for other kinds of roof. The expense at Tew Lodge was from fourpence to tenpence per square foot, everything included. It is one result of the flatness of the roof, that ten square feet will cover as much as fourteen feet at the usual pitch of slated roofs. As to the durability, many proofs are adduced to support it. A paper roof to a church at Dunfermline remained forty years without requiring any repairs; and several warehouses at Greenock, Deal, Dover, and Canterbury, had paper roofs, which were known to stand from ten to twenty years. Mr. Loudon considered that, from the flatness of the roofs, and from other circumstances connected with the appearance of the prepared sheets, the paper roofs were more fitted to join harmoniously with certain styles of architecture than slated roofs.

Objections have been made to this kind of roof, on the ground that it is liable to be blown off by high wind, and still more that it is very inflammable. With regard to the former, Mr. Loudon states that if the roof be properly made there is little danger of its being removed by high wind. In reference to the second objection, he states:—“They seem to me not so liable to set fire to as thatch. Pitch (especially if coated over with sand or smithy ashes) will not be lighted by a spark, nor even by the application of a slender flame, as will that material; though, on the other hand, when lighted, it will unquestionably burn with greater velocity than any species of thatching.... In the steward’s house and men’s lodge wood is constantly used as fuel, which, though more dangerous for emitting sparks than coal, yet no accident has or is ever likely to happen to the roof. In my house, where coals were chiefly used, the chimneys have been repeatedly set on fire to clean them, without the least accident happening to the roof.”

Many years afterwards, when Mr. Loudon published his elaborate Encyclopædia of Cottage, Farm, and Villa Architecture, he briefly sketched some of the forms of roof which have more or less recently come into use. These we must here notice.

Terrace Roofs.

Terrace roofs have been much used in and about London. They are formed of thin arches of tiles and cement, supported on cast-iron bearers or ribs, which are placed about three feet apart. The arch is composed of three courses of common plain tiles, bedded in fine cement without sand. In laying the tiles, laths or small slips of wood are used, resting on temporary bearers between the iron ribs; the laths being shifted as the work advances, in the course of about half an hour after the tiles are laid. Particular attention is required in bonding the tiles both ways; and they are rubbed down closely upon each other, much in the same manner as a joiner glues a joint. Sometimes these terrace roofs are coated with a layer of coarse gravel, and then with nine inches of good soil, so as to form a terrace garden. The roofs of two taverns at Hungerford Market are formed of these cemented tiles.

Asphalte Roofs.

Asphalte or bitumen has come into use as a material for roofs. It had been employed for various purposes in France for many years, but did not attract much attention till within the last eight or ten years. It is now in very general use in that country for foot pavements, flat roofs, and water-cistern linings; and in England it has also been a good deal used for the same purposes, and for barn-flooring. The particular modes in which it is employed for floors and pavements we need not here consider, but it has been used for roofs in the following manner. Mr. Pocock has patented a “flexible Asphaltic roofing,” intended to supersede the use of slates, tiles, zinc, thatch, &c., in the covering and lining of farm-buildings, sheds, cottages, and other erections; and it is approved for its durability, lightness, and economy. The weight of this material being only sixty pounds to the square of one hundred feet, the walls and timbers to support it need to be but half the usual substance; it is also a non-conductor of heat, impervious to damp, and will bear a heat of two hundred and twenty degrees without injury. This peculiar material is said to be formed of asphalte mixed with the refuse felt of hat manufactories, compressed into thin plates.

Scotch Fir Roofs.

Scotch fir roofs are occasionally made. The method of giving durability to the timber for this purpose consists in first cutting the wood to the required size, and then steeping it for a fortnight in a pond of lime-water; it is found that the acid contained in the wood becomes crystallized by combining with the alkali of the lime. Sir Charles Menteath is said to have some farm buildings which, although roofed with Scotch fir forty years ago, are as well protected now as when the roofs were first laid on; the wood having been previously steeped in lime-water. The sulphate of copper, the chloride of zinc, the corrosive sublimate, and the various other chemical substances which have been recommended of late years as means for preventing the decay of timber, will possibly render the use of timber roofs more practicable than it has been hitherto considered.

Iron Roofs.

Roofs of iron are in great request at the present time. One of these sorts of roofs may be formed of three kinds of cast-iron plates. The first, called the “roof-plate,” is shaped with three of its sides turned up and one turned down, and is made tapering narrower towards one end; the second, called the “low-ridge plate,” has two of its sides turned up and the other two turned down; the third, called the “high-ridge plate,” has all its sides turned down, and is formed with an angle in the middle, so as to slope each way of the roof. Such a roof may be made very flat, inasmuch, that for a house twenty feet wide, the height of the roof in the middle need not exceed two feet; no boarding is required, the plates resting without either cement or nails on the rafters. From the manner in which the edges of the plates overlap, there is no risk of contraction or expansion.

Some of the iron roofs recently made are on the principle of those used in Russia, of which the following description has been given in the Repertory of Patent Inventions:—“Sheet-iron coverings are now universally made use of in all new buildings at Petersburgh, Moscow, &c. In the case of a fire, no harm can come to a house from sparks falling on a roof of this description. The sheets of this iron covering measure two feet four inches by four feet eight inches, and weigh twelve pounds and a half avoirdupois per sheet, or one pound five ounces each superficial square foot. When the sheets are on the roof, they measure only two feet wide by four feet in length: this is owing to the overlapping. They are first painted on both sides once, and, when fixed on the roof, a second coat is given. The common colour is red, but green paint, it is said, will stand twice the time. Small bits or ears are introduced into the laps, for nailing the plates to the two-inch square laths on which they are secured. It takes twelve sheets and a half to cover one hundred feet, the weight of which is one hundred and fifty pounds—the cost only £1 15s., or about threepence per foot.”

Iron roofs are now often made of corrugated or furrowed sheet-iron. In this form the iron is impressed so as to present a surface of semi-circular ridges with intervening furrows lengthwise of the sheets. By this means, a piece of sheet-iron, which, as a plain flat surface, has no strength but in its tenacity, becomes a series of continued arches abutting against each other; and the metal, by this new position, acquires increased strength. Iron so furrowed is deemed preferable to common sheet-iron for covering a flat-roof, because the furrows will collect the water and carry it more rapidly to the eaves. But there are greater advantages than this. If the furrowed sheets be bent into a curved surface, convex above and concave below, they will form an arch of great strength, capable of serving as a roof without rafters or any other support, except at the eaves or abutments. Iron roofs measuring two hundred and twenty-five feet by forty have been constructed in this manner. To increase their durability the iron sheets are coated with paint or tar.

Zinc and other Metallic Roofs.

Additions are made every year to the number of contrivances for forming metallic roofs, among which is one now the subject of a patent, for the use of galvanized iron. In this case the aid of the electric agent is employed to give iron sheets an amount of durability which they do not possess in their natural state.

Zinc has been much employed within the last few years as a material for roofs. Its availability for this purpose rests partly on its superior lightness as compared with lead, and its superior condition under the action of the atmosphere as compared with iron. The latter quality arises thus; after the zinc has been covered with a thin film of oxide by the action of the atmosphere, it suffers no further change from long exposure; so that the evil of rust checks itself. At the temperature of boiling water, zinc sheets, which are brittle when cold, become malleable, and their availability for roofs is thereby increased. The property which zinc has, however, of taking fire at a temperature of about 700° Fahr., rather detracts from its value as a material for roofs.

Thatch Roofs.

The most common material employed as thatch is either the straw of wheat, rye, or other grain, or reed, stubble, or heather. The straw of wheat and rye, when well prepared and laid, forms the neatest and most secure thatching; the former being preferable to the latter in smoothness, suppleness, and durability. Barley-straw is placed next to rye in fitness for thatch, and oat-straw the lowest of the four. The reed is a very durable material for thatch, but is generally too expensive. It has been stated that, in Norfolk, where the reed is a favourite material for thatch, a reed roof will lie fifty years without wanting repair, and that, with very slight attention, it will last for a whole century. Viewed in this light, a reed roof may probably be considered economical.

The method of thatching with reed, (which is one of the best and most difficult specimens of the thatcher’s art,) has been thus described. No laths being made use of as a support to the thatch, a few of the longest and stoutest reeds are scattered irregularly across the naked spars as a foundation whereon to lay the main coat; and thus a partial gauze-like covering is formed, called the fleaking. On this fleaking the main covering is laid, and fastened down to the spars by means of long rods called sways, laid across the middle of the reed, and tied to the spars with rope-yarn or with brambles. In laying on the reed, the workman begins at the lower corner of the roof on his right hand, and keeps an irregular diagonal line until he reaches the upper corner on his left; a narrow eaves-board being nailed across the feet of the spars, and some fleaking scattered on. The thatcher begins to “set his eaves” by laying a coat of reed, eight or ten inches thick, with the heads resting upon the fleaking and the butts upon the eaves-board. He then lays on his sway, or rod, about six or eight inches from the lowest point of the reed, whilst his assistant, on the inside, runs a needle threaded with rope-yarn close to the spar and to the upper edge of the eaves-board. The thatcher draws it through on one side of the sway and enters it again on the contrary side both of the sway and of the spar. The assistant, in his turn, draws it through, unthreads it, and, with the two ends of the yarn, makes a knot round the spar, thereby drawing both the sway and the reed tight down to the roof; whilst the thatcher above, beating and pressing the sway, assists in consolidating the work. The assistant, having made good the knot below, proceeds with another length of thread to the next spar, and so on till the sway is bound down the whole length, that is, about eight or ten feet. This being done, another stratum of reed is laid upon the first, so as to make the entire coat eighteen or twenty inches thick at the butts; and another sway is laid on and bound down about twelve inches above the first.

When the eaves are completely set they are adjusted and made even by an instrument called a legget. This is made of a board eight or nine inches square, with a handle two feet long adjusted to its upper surface in an oblique position. The face of the legget is set with large-headed nails, and these enable the workman, by using the instrument somewhat as if it were a turf-beating tool, to lay hold of the butts of the reed and to adjust them in their places. When the eaves are thus shaped, the thatcher lays on another stratum of reeds, and binds it down by another sway somewhat shorter than the last, and placed eighteen or twenty inches above it; and above this, others, in successive rows, continuing to shorten the sways until they diminish to nothing, and a triangular corner of thatching be formed. After this the remaining surface of the roof is similarly done.

In order to finish the ridge of the roof, a cap of straw is adjusted to it in a very careful manner. In this operation the workman begins by bringing the ridge to a sharp angle, by laying straw lengthwise upon it: and to keep this straw in its place, he pegs it down slightly with “double-broaches,” which are cleft twigs about two feet long and half an inch thick, sharpened at both ends, bent double and notched, so as to clasp the straw on the ridge. This done, the thatcher lays a coat of straight straw six or eight inches thick across the ridge, beginning on either side at the uppermost butts of the reeds, and finishing with straight handsful evenly across the top of the ridge. Having laid a length of about four feet in this manner, he proceeds to fasten it firmly down, so as to render it proof against wind and rain; this is done by laying a “broachen-ligger” (a quarter-cleft rod, half an inch thick and four feet long) along the middle of the ridge, pegging it down at every four inches with a double-broach, which is first thrust down with the hands, and afterwards driven with the legget or with a mallet. The middle ligger being firmly laid, the thatcher smooths down the straw with a rake and his hands, about eight or nine inches on one side; and at six inches from the first, he lays down another ligger, and pegs it down with a similar number of double-broaches, thus proceeding to smooth the straw and to fasten on liggers at every six inches, until he reaches the bottom of the cap. One side being thus finished, the other is similarly treated; and the first length being completed, others are done in like manner, till the farther end of the ridge is reached. He then cuts off the tails of the straw neatly with a pair of shears, level with the uppermost butts of the reed.

When straw or heather is used for thatching, the material is laid on in parallel rows, much the same as the reeds, but the mode of fastening is generally somewhat different.

Chapter V.
THE WOOD-WORK. GROWTH AND TRANSPORT OF TIMBER.

The operations of the carpenter and joiner in the preparation of the wood-work of a house are quite as important as those of the mason or bricklayer. It would not be possible in this little volume to trace clearly all the different processes connected with the building of a house as they occur in practice; for the bricklayer and the carpenter combine their work, as it were, step by step. But as the bricklaying and the slating, or tiling, relate principally to the exterior of the house, and the carpentry work to the interior, we have thus a line of separation, which will greatly contribute to the clearness of these details.

As on a former occasion we noticed the operations of the quarry, whence the builder is supplied with stone, slate, &c., it will now be interesting to give a few details respecting the growth and transport of timber.

The Oak as a Timber Tree.

It is obvious that in every country native timber is preferred, provided it can be obtained in sufficient quantity at a cheap rate; if not, it is imported from other countries. In Britain, the first and most important of all trees is, of course, our own oak, of which we have two species and several varieties, belonging to the genus Quercus.

The two species of oak natives of Britain, though greatly resembling each other in general appearance, may yet very readily be distinguished, when once their specific characters are pointed out. As these two species are very commonly confounded together, and as one of them is believed to afford a far more valuable timber than the other, it may be useful to note their difference, and exhibit the characters by which each may be known.

The true British oak, Quercus robur, (fig. 1) bears its acorns on a stalk, or peduncle (fig. 1, A), and hence it is sometimes called Quecus pedunculata, but its leaves grow close to the stem, without a footstalk, or at least with a very short one. In the other native species (fig. 2), these two characters are reversed: the leaves grow upon a footstalk, while the acorns are produced sessile, that is, sitting close to the stem (fig. 2, A); from which latter character this species has acquired the name of Quercus sessiliflora.

The above characters will, for the most part, be found pretty constant. At the same time, it may be remarked, that the oak is a tree subject to great variations; and accordingly individuals of each species occasionally occur, which in their characters are found more or less to approach those of the other. Quercus robur, for example, sometimes bears its acorns almost close to the stem, and sometimes Quercus sessiliflora will bear them on a short footstalk. The leaves, too, of each, frequently vary in the length of the petiole, or leafstalk. But in a general way (as already stated), each kind may be readily distinguished by the above obvious points of difference.

Both species are common in Britain, though Quercus sessiliflora appears to be not so generally distributed as the other; in many districts its growth seems to be principally confined to woods and coppices, where it sometimes occurs even in greater abundance than the common species. Quercus robur is believed to afford the more valuable timber of the two, owing, probably, to its being of slower growth. It is doubtful, however, whether the respective merits of each, in point of durability of timber, have yet been fairly put to the test. Where oak is grown in coppices, to be cut down periodically for poles, Quercus sessiliflora is at least a valuable, perhaps a preferable tree, on account of its more rapid and cleaner growth.

No certain specific characters, we are aware, can be derived from the mere size or shape of the acorns, or of the leaves. It may be mentioned, however, as a general, though not a constant rule, that Quercus sessiliflora usually bears very small acorns, and that its leaves are, for the most part, larger, and more regularly laciniated or notched, and consequently handsomer, as individual leaves, than those of Quercus robur. The foliage of the latter species, however, taken as a whole, is by far the more beautiful; its leaves, being smaller, and growing close to the stem, and not on footstalks, combine better, form more dense and compact masses, and exhibit to greater perfection those exquisite tufts, or rosettes, which constitute one of the peculiar charms of oak foliage.

The oak is far less used in civil architecture than formerly, although there are certain purposes in building to which it is still applied; but owing to its value and the demand for it for ships, and to the great labour required to work it, its place is now supplied by fir. The best oak is that which grows on cold, stiff, clayey soils, and is the slowest in arriving at maturity; and the colder the climate, or the higher above the level of the sea the tree grows, provided it be not stunted from severity of climate, the better the timber: hence Scottish and Welsh oak is more esteemed than that from the middle or southern counties of Britain. Our own island does not produce this timber in sufficient abundance to supply the demand, and large quantities of oak are imported from different countries, especially from Prussia and Canada. There are four kinds of oak used in the Royal Dock-yards,—Welsh, Sussex, Adriatic, and Baltic,—besides two others, termed African oak, employed in different parts of the vessels, according to the qualities requisite for the particular purpose. Next to our own oak, that from the shores of the Baltic is by far the most esteemed.

In domestic architecture, oak is only used in the largest and best buildings, occasionally for the principal beams; but its chief use is for door and window frames, sills, sleepers, king-posts of roofs, for trussing fir girders, for sashes, for gates of locks, sluices, posts, piles, &c. The timber called African oak, used in the navy, is wood of a different genus.

Wainscot is the wood of a species of oak, imported from Russia and Prussia in a particular form of log.

Teak is the produce of a tree of the genus Tectona. T. grandis is one of the largest Indian trees, and one of the most valuable, on account of its excellent timber. The trunk is neat, lofty, and of an enormous size; the leaves about twenty inches long and a foot or more wide; the flowers small, white, and fragrant, and collected into very large panicles. It is a native of various parts of India, and was introduced into Bengal by Lord Cornwallis and Colonel Kydd. The wood of this tree has been proved by long experience to be the most useful timber in Asia; it is light and easily worked, and at the same time strong and durable. It is considered equal to oak for ship-building, and has some resemblance to it in its timber; many vessels trading between this country and India are constructed of it. That which grows near the banks of the Godavery is beautifully veined, closer in the grain, and heavier than other varieties. “On the banks of the river Irrawaddy, in the Birman empire, the teak forests are unrivalled; and they rise so far over the jungle or brushwood, by which tropical forests are rendered impenetrable, that they seem almost as if one forest were raised on gigantic poles over the top of another. The teak has not the broad strength of the oak, the cedar, and some other trees; but there is a grace in its form which they do not possess.” A specimen of this tree was introduced into the Royal Gardens at Kew about seventy years ago; but from the coldness of our climate it can never become a forest-tree in this country.

Valuable as teak is found to be in ship-building, it has not yet been used in domestic building to any extent. From sixteen to eighteen thousand loads of teak are annually imported into Britain from India, principally for the Royal Dock-yards, this wood being used for certain beams and pillars in ships.

The Fir and Pine as Timber Trees.

Fir, or Pine, ranks next to oak for its valuable qualities, and if its universal application be taken into consideration, it might be thought even superior in importance. It is used for every part of houses, and extensively in ship-building, in the fittings-up, while it constitutes the only material for masts, for which purpose its lightness, and the great length and straightness of the trunk, peculiarly fit it.

Pine, or fir, is imported into this kingdom under the various names of timber, battens, deals, laths, masts, yards, and spars, according to the size or form into which the tree is sawed. It is called timber when the tree is only squared into a straight beam of the length of the trunk, and from not less than eight or nine inches square, up to sixteen or eighteen square; fifty cubic feet is a load of timber. Deals vary in length and thickness from eight to sixteen feet, eleven inches wide, and from one and a half to three and a half inches thick. Four hundred superficial feet of one and a half inch plank make a load. Battens are small long pieces of fir about three inches wide and one inch thick. Masts, yards, and spars, are the trunks of small trees simply barked and topped.

The pine is, generally speaking, an evergreen, and the wood becomes harder and more durable when the situation is cold, and also when the growth of the tree is slow. Norway, Sweden, the shores of the Baltic, and Canada, are the chief localities of the forests of pine. England is supplied principally from Canada, not because the timber from that country is better than that derived from the north of Europe, but because our timber duties fall heavily on the European pine, the object of the legislature being to encourage the importation of pine from our North American colonies.

Almost the whole of what is now called Canada was once an immense pine forest. With respect to the Baltic region, Dr. Clarke said, that if we take up a map of Sweden, and imagine the Gulf of Bothnia to be surrounded by one contiguous unbroken forest, as ancient as the world, consisting principally of pine trees, with a few mingling birch and juniper trees, we shall have a general and tolerably correct notion of the real appearance of the country. The same writer observed, that the King of Sweden might travel from sunrise to sunset through some parts of his territories, without meeting any other of his subjects than pine trees.

The Norway Spruce Fir.

The species of Spruce Fir (Pinus abies), represented in the engraving, has been known as a British tree for more than three hundred years, but Norway seems, as far as it can be ascertained, to be its native country. It differs from the Scotch fir in general appearance, as well as in the structure of its leaves and cones. The beautiful feathery appearance of its foliage is very striking, but the extreme regularity of its form rather detracts from the beauty of a landscape when it is too often repeated; it is easily known by its long pendulous cones, as well as by its formal shape. The spruce fir is found in great abundance in all the Norwegian forests; it is also spread over the whole of the north of Europe, and part of Asia, and it occurs on most of the mountain-ranges of both these quarters of the globe; in favourable situations it attains a great height, as much at times as 150 feet.

The Norway Spruce Fir.

The spruce grows more rapidly than any other of the fir tribes; its wood is extremely tough and strong, and answers well for masts and spars, but it is not so valuable when cut into planks as that of other species. It does not attain the same size in Britain as in colder climates, the tree perhaps being weakened by the loss of its sap, which in hot weather is discharged through the bark in considerable quantities. The more protracted season of growth, and the greater difference between the temperature of the day and the night, must have an effect upon it, and judging from the situations which it prefers on the Continent, the summer rains of England cannot be by any means favourable. The almost continual day in the Polar countries, while vegetation is active, produces a uniformity of temperature, and a consequent uninterrupted growth day and night, while in countries farther south, the vegetable action is checked every night, and renewed again every morning, especially in the early part of the season, when such alternations are most dangerous.

1 1 Male Catkins, or Blossoms.
2 2 2 Cones containing the Seed.

The Norway Spruce is called by the French the Pitch Spruce, from its yielding the Burgundy Pitch of commerce. To obtain this, parts of the bark are removed in the spring, and the resin exudes in greater or smaller quantities, according to the state of the tree; this is scraped off from time to time. After a sufficient quantity has been collected, it is melted in hot water, and strained through bags to separate the impurities. If the strips of bark which are removed are narrow, the trees will continue to yield for several years.

The Norway Spruce, and all other trees of the fir tribe, are propagated by means of seeds. These are to be sown rather thinly about the middle of March, in a shady well-sheltered border; towards the autumn the ground is to be carefully weeded, and a quantity of rich earth strewed lightly over the whole. During the winter, if the frosts are very severe, the young plants ought at times to be protected from the severity of the weather. In the next spring, and during the months of May and June, the young plants will be much assisted by frequent waterings, and in the autumn the ground must be again cleaned. In the succeeding spring, when their heads begin to swell, they may be removed. At four years old they may be transplanted again to a spot of good land, and placed in rows two and a half feet asunder, and fourteen or sixteen inches distant in each row. Three years after they will again require to be transplanted four feet asunder, and so on, increasing the space between the trees at each remove, until the young ones are fourteen or sixteen feet in height.

The Scotch Fir.

One of the most useful kinds of pine is the Pinus Sylvestris (wild pine), generally known as Scotch fir. It is this tree which produces that kind of wood so extensively useful to the carpenter under the name of deal. The term “deal” implies timber squared into a convenient size for exportation, and it is in the form of deals that the wood of which we are now speaking is imported into England from Norway and the Baltic. The best part of this wood is near the root; and the roots themselves are valuable for many purposes. It is of this wood that the bodies of violins and the sounding boards of musical instruments generally, are made: the grain of the wood formed by the annual layers being very straight and regular. In trees which have not arrived at maturity, there is a portion of sap-wood next the bark; this sap-wood is converted into ligneous matter in about two or three years from its formation.

The Scotch Fir.

The Scotch Fir, or Pine, is not peculiar to Scotland, but is common to all the mountain-ranges of Europe; in low damp situations it never thrives, but delights in the exposed summits of the loftiest rocks, over which the earth is but thinly scattered; there its roots wander afar in the wildest reticulation, whilst its tall, furrowed, and often gracefully-sweeping, red and gray trunk, of enormous circumference, rears aloft its high umbrageous canopy.

The fir was a very great favourite with Gilpin, who considered it, as it really is, to be under favourable circumstances, a very picturesque object in a landscape: the earnestness with which he defends its character is peculiarly forcible; he says, “It is a hardy plant, and, therefore, put to every servile office. If you wish to screen your house from the south-west wind, plant Scotch firs, and plant them close and thick. If you want to shelter a nursery of young trees, plant Scotch firs, and the phrase is, you may afterwards weed them out at your pleasure. This is ignominious. I wish not to rob society of these hardy services from the Scotch fir, nor do I mean to set it in competition with many trees of the forest, which, in their infant state, it is accustomed to shelter; all I mean is, to rescue it from the disgrace of being thought fit for nothing else, and to establish its character as a picturesque tree. For myself, I admire its foliage, both the colour of its leaf and its mode of growth. Its ramification, too, is irregular and beautiful.”

The practice of planting this tree in groups is the cause to which its unfavourable character, as a picturesque object, may be attributed, the closeness of growth causing the stems to run upward without lateral branches. The hilly regions of the whole of Great Britain and Ireland were formerly covered with vast forests, a great portion of which consisted of fir-trees. Of these ancient forests some remains still exist; in Scotland, the relics of the Rannock forest, on the borders of the counties of Perth, Inverness, and Argyle, are well known: these consist of the roots and a few scattered trees, which are still found in situations of difficult access. This forest appears to have stretched across the country, and to have been connected with the woody districts of the west of Scotland. The Abernethy forest, in Perthshire, still furnishes a considerable quantity of timber.

“At one time,” we quote Sir Thomas Dick Lauder, Bart., “the demand for it was so trifling, that the Laird of Grant got only twenty pence for what one man could cut and manufacture in a year. In 1730 a branch of the York Buildings Company purchased seven thousand pounds’ worth of timber, and by their improved mode of working it, by saw-mills, &c., and their new methods of transporting it in floats to the sea, they introduced the rapid manufacture and removal of it, which afterwards took place throughout the whole of the sylvan districts. About the year 1786 the Duke of Gordon sold his Glenmore forest to an English company for 10,000l. This was supposed to be the finest fir-wood in Scotland. Numerous trading vessels, some of them above five hundred tons burden, were built from the timber of this forest, and one frigate, which was called the Glenmore. Many of the trees felled measured eighteen and twenty feet in girth, and there is still preserved at Gordon Castle a plank nearly six feet in breadth, which was presented to the Duke by the Company. But the Rothienmurchus forest was the most extensive of any in that part of the country; it consisted of about sixteen square miles. Alas! we must indeed say, it was, for the high price of timber hastened its destruction. It went on for many years, however, to make large returns to the proprietor, the profit being sometimes 20,000l. a year.”

Leaves and Male Blossom of Scotch Fir.

Cone of Scotch Fir.

Besides the forest we have mentioned, there are still in existence other tracts of land in different parts of Scotland covered with this timber. The attention which has been drawn to the value of the Scotch fir has been an inducement to proprietors of land to cause extensive plantations to be formed on suitable spots; but Nature herself takes measures to perpetuate her work where the hand of man has carried destruction; for, after the old trees have been felled and carried off the ground, young seedlings come up as thick as in the nurseryman’s seed bed.

The timber supplied by the Scotch fir is called Red Deal, and the uses to which it is applied render it necessary that the stem should be straight, and close planting materially assists in this object, by preventing the possibility of the trees flinging out their lateral branches; this, as we have already noticed, disfigures the tree in the eye of an artist, however much it may delight that of a timber merchant. The straightest and cleanest-grown trees are selected for masts, spars, scaffold-poles, &c., while the largest sticks are sawed into planks for various purposes. Its wood is very durable, and resists the action of water excellently. The persons employed at different times in the endeavour to rescue the cargo of the Royal George, which foundered off Spithead, in the year 1782, discovered that the fir-planks had suffered little, if any injury, while the other timbers of the vessel had been much acted upon by the water and different species of worms.

In Holland this tree has been used for the purpose of preparing the foundations of houses in their swampy soil; 13,659 great masts of this timber were driven into the ground for the purpose of forming the foundation of the Stadthouse at Amsterdam. But it is not only for its timber that we are indebted to this tree; those useful articles, tar, pitch, and turpentine, are all yielded by its sap.

Transport of Timber from the Forests.

Probably but few of our readers think of the means by which timber is conveyed from the forest where it grows, to the spots where it is to be applied to the purposes of building. And yet it must be evident that the means of transport form a matter of no small importance. We know that our timber-yards are plentifully supplied with the various kinds of wood necessary for building; and that the timbers are shaped by the axe and the saw. But, in most cases, the wood which we employ is brought from foreign countries, often many miles inland. It is conveyed across the ocean in ships; but the mode of transporting it from the forests where it grows to the ports where it is to be shipped, is a curious subject, and one well worthy of a little attention.

The main circumstance that forms the groundwork of all the plans adopted for this purpose is, that nearly all kinds of wood are, bulk for bulk, lighter than water, and will consequently swim on its surface. Now as all countries are, more or less intersected by rivers, which flow from the interior into the sea, a very simple and economical mode of transport for timber is at once attained, by causing it to float down running streams, either by the mere force of the descending water, or by the aid of mechanical agents. There is no necessity that each piece of wood should be floated separately down the stream; for they may be fastened together and steered down the middle of the river, in the form of a long and broad raft.

Beckmann says: “It is probable that the most ancient mode of constructing vessels for the purpose of navigation, gave rise to the first idea of conveying timber in the like manner; for the earliest ships or boats were nothing else than rafts, or a collection of beams and planks bound together, over which were placed deals. By the Greeks they were called schedai, and by the Latins rates; and it is known, from the testimony of many writers, that the ancients ventured out to sea with them, on piratical expeditions, as well as to carry on commerce; and that after the invention of ships, they were still retained for the transportation of soldiers, and of heavy burdens.”

There are some passages in the Bible which allude to the floating of wood. 1 Kings v. 9: “My servants shall bring them down from Lebanon unto the sea; and I will convey them by sea in floats unto the place that thou shalt appoint me.” 2 Chron. ii. 16: “And we will cut wood out of Lebanon, as much as thou shalt need: and we will bring it to thee in floats by sea to Joppa, and thou shalt carry it up to Jerusalem.” These passages relate to a compact between Solomon and Hiram, king of Tyre, by which the latter was to cause cedars for the building of the Temple to be cut down on the western side of Mount Lebanon, above Tripoli, and to be floated to Jaffa or Joppa, probably along by the sea shore.

The Romans transported by water both timber for building and fire-wood. When, during their wars against the Germans, they became acquainted with the qualities of the common larch, they caused large quantities of it to be carried on the river Po, to Ravenna, from the Alps, particularly the Rhætian, and to be conveyed also to Rome, for their most important buildings. Vitruvius says, that this timber was so heavy that the waters could not support it, and that it was necessary to carry it in ships or on rafts. Could it have been brought to Rome conveniently, says he, it might have been used with great advantage in building. It has also been supposed that the Romans procured fire-wood from Africa, and that it was brought partly in ships and partly on rafts.

But it is in Germany that the transportation of timber by means of floats has been most extensively carried on, partly on account of its noble forests, and partly through the possession of the river Rhine. There is evidence of the floating of timber-rafts in Germany so far back as the year 1410. A letter from the Landgrave of Thuringia says, that on account of the scarcity of wood that existed in their territory, the landgraves had so far lessened the toll usually paid on the river Sale as far as Weissenfels, that a Rhenish florin only was demanded for floats brought on that river to Jena, and two Rhenish stivers for those carried to Weissenfels; but the proprietors of the floats were bound to be answerable for any injury occasioned to the bridges.

In 1438, Hans Munzer, an opulent citizen of Freyberg, with the assistance of the then burgomasters, put a float of wood upon the river Mulda, which runs past the city, in order that it might be conveyed thither for the use of the inhabitants: this seems to imply that such a practice was not then uncommon. When the town of Aschersleben was adorned with a new church, in 1495, the timber used for its construction was transported on the Elbe, from Dresden to Acken, and from thence on the Achse to the place of its destination. In the year 1561, there was a float-master in Saxony, who was obliged to give security to the amount of four hundred florins; so that at that time the business of floating must have been of considerable importance.

When the citizens of Paris had used all the timber growing near the city, the enormous expense of land carriage led to the suggestion of an improved mode of transport. John Rouvel, a citizen and merchant, in the year 1549, proposed to transport timber, bound together, along rivers which were not navigable for large vessels. With this view he made choice of the forests in the woody district of Morvant, which belonged to the government of Nivernois; and as several small streams and rivulets had their sources there, he endeavoured to convey into them as much water as possible. This great undertaking, at first laughed at, was completed by his successor, René Arnoul, in 1566. The wood was thrown into the water in single trunks, and suffered to be driven in that manner by the current to Crevant, a small town on the river Yonne; where each timber-merchant drew out his own, which he had previously marked, and after it was dry, formed it into floats that were transported from the Yonne to the Seine, and thence to the capital. By this method large quantities of timber were conveyed to the populous towns.

A similar mode of transporting timber from the central parts of Germany to the great towns or to the seaports is practised at the present day. Mr. Planché, in his Descent of the Danube, says: “Below this bridge, (at Plattling on the Danube,) the raft-masters of Munich, who leave that city every Monday for Vienna, unite their rafts before they enter the Danube. They descend the Isar upon single rafts only; but upon reaching this point, they lash them together in pairs, and in fleets of three, four, or six pairs, they set out for Vienna. A voyage is made pleasantly enough upon these floating islands, as they have all the agrémens, without the confinement of a boat. A very respectable promenade can be made from one end to the other, and two or three huts erected upon them afford shelter in bad weather, and repose at night.”

But the anonymous author of An Autumn near the Rhine gives a more detailed account of the timber-rafts of Germany, of which we will avail ourselves. A little below Andernach, on the banks of the Rhine, the small village of Namedy appears on the left bank, under a wooded mountain. The Rhine here forms a little bay, where the pilots are accustomed to unite together the lesser rafts of timber, floated down the tributary rivers into the Rhine, and to construct enormous floats, which are navigated to Dordrecht and sold. These machines have the appearance of a floating village, composed of twelve or fifteen huts, on a large platform of oak and deal timber. They are frequently eight or nine hundred feet long, and sixty or seventy in breadth. The rowers and workmen sometimes amount to seven or eight hundred, superintended by pilots and a proprietor, whose habitation is superior in size and elegance to the rest. The raft is composed of several layers of trees, placed one on the other, and tied together. A large raft draws not less than six or seven feet water. Several smaller ones are attached to it, by way of protection, besides a string of boats, loaded with anchors and cables, and used for the purpose of sounding the river, and going on shore. The domestic economy of an East Indiaman is hardly more complete. Poultry, pigs, and other animals, are to be found on board, and several butchers are attached to the suite. A well-supplied boiler is at work night and day in the kitchen. The dinner hour is announced by a basket stuck on a pole, at which signal the pilot gives the word of command, and the workmen run from their quarters to receive their allowances.

The consumption of provisions in the voyage to Holland is almost incredible, sometimes amounting to forty or fifty thousand pounds of bread, eighteen or twenty thousand pounds of fresh meat, a considerable quantity of salt meat, and butter, vegetables, &c., in proportion. The expenses are so great, that a capital of three or four hundred thousand florins is considered necessary to undertake a raft. Their navigation is a matter of considerable skill, owing to the abrupt windings, the rocks and shallows of the river; and some years ago the secret was thought to be monopolized by a boatman of Rudesheim and his son.

The timber of the spruce firs which grow on the sides of the Alps, is considered much finer than that which is produced in other situations; but the inaccessible nature of these Alpine forests long prevented those useful trees from being sent in any great quantity to the market. During our long continental war, however, a bold and skilful plan was invented, by which this timber was procured in abundance. M. Rupp, an enterprising foreigner, constructed an immense inclined plane of wood on the sides of Mount Pilatus, near the Lake Lucerne; its length was eight miles and a half. Twenty-five thousand large pine trees were employed in its construction. These were barked and put together very ingeniously, without the aid of iron. It occupied one hundred and sixty workmen during eighteen months, and cost nearly a hundred thousand francs, or 4250l. sterling. It was completed in the year 1812.

The following description of the slide appeared in a German periodical shortly after its completion:—“This slide has the form of a trough, about six foot broad and from three to six foot deep. Its bottom is formed of three trees, the middle one of which has a groove cut out in the direction of its length, for receiving small rills of water, which are conducted into it from various places, for the purpose of diminishing the friction. The whole of the slide is sustained by about two thousand supports; and in many places it is attached, in a very ingenious manner, to the rugged precipices of granite.

“The direction of the slide is sometimes straight, and sometimes zig-zag, with an inclination of from 10° to 18°. It is often carried along the sides of hills and the flanks of precipitous rocks, and sometimes passes over their summits. Occasionally it goes under ground, and at other times it is conducted over the deep gorges by scaffoldings one hundred and twenty feet in height.

“The boldness which characterizes this work, the sagacity and skill displayed in all its arrangements, have excited the wonder of every person who has seen it. Before any step could be taken in its erection, it was necessary to cut several thousand trees to obtain a passage through the impenetrable thickets. All these difficulties, however, were surmounted, and the engineer had at last the satisfaction of seeing the trees descend from the mountain with the rapidity of lightning. The larger pines, which were about a hundred feet long, and ten inches thick at their smaller extremity, ran through the space of three leagues, or nearly nine miles, in two minutes and a half, and during their descent, they appeared to be only a few feet in length. The arrangements for this part of the operation were extremely simple. From the lower end of the slide to the upper end, where the trees were introduced, workmen were posted at regular distances, and as soon as everything was ready, the workman at the lower end of the slide cried out to the one above him, ‘Lachez’ (Let go.) The cry was repeated from one to another, and reached the top of the slide in three minutes. The workman at the top or the slide then cried out to the one below him, ‘Il vient’ (It comes), and the tree was instantly launched down the slide, preceded by the cry which was repeated from post to post. As soon as the tree had reached the bottom, and plunged into the lake, the cry of Lachez was repeated as before, and a new tree was launched in a similar manner. By these means a tree descended every five or six minutes, provided no accident happened to the slide, which sometimes took place, but which was instantly repaired when it did.

“In order to show the enormous force which the trees acquired from the great velocity of their descent, M. Rupp made arrangements for causing some of the trees to spring from the slide. They penetrated by their thickest extremities no less than from eighteen to twenty-four feet into the earth; and one of the trees having by accident struck against another, it instantly cleft it through its whole length, as if it had been struck by lightning.

“After the trees had descended the slide, they were collected into rafts upon the lake, and conducted to Lucerne. From thence they descended the Reuss, then the Aar to near Brugg, afterwards to Waldshut by the Rhine, then to Basle, and even to the sea when it was necessary.

“It is to be regretted that this magnificent structure no longer exists, and that scarcely a trace of it is to be seen upon the flanks of Mount Pilatus. Political circumstances having taken away the principal source of demand for the timber, and no other market having been found, the operation of cutting and transporting the trees necessarily ceased.”[4]

Professor Playfair, who visited this singular work, states, that six minutes was the usual time occupied in the descent of a tree; but that in wet weather, it reached the lake in three minutes. He found it quite impossible to give two successive strokes of his stick to any, even the largest tree, as it passed him. The logs entered the lake with such force, that many of them seemed to penetrate its waters to the very bottom. Much of the timber of Mount Pilatus was thus brought to market; but the expense attending the process rendered it impossible for the speculator to undersell the Baltic merchant, when peace had opened a market for his timber, and so the Slide of Alpnach fell to ruin.

Cutting the Norway Deals.

When the timber is squared before it is exported, it is effected by saw-mills; the manner of proceeding may be illustrated by the treatment of Norway deals. In some cases, the trees are merely roughly-shaped with the axe; but those which are to be made into deals are floated down the mountain-streams to a spot where many collect together, and where a saw-mill is erected. Dr. Clarke thus speaks of one that he visited:—“The remarkable situation of the sawing-mills, by the different cataracts, are among the most extraordinary sights a traveller meets with. The mill here was as rude and picturesque an object as it is possible to imagine; it was built with the unplaned trunks of large fir-trees, as if brought down and heaped together by the force of the river. The saws are fixed in sets parallel to each other, the spaces between them in each set being adapted to the intended thickness for the planks. A whole tree is thus divided into planks, by a simultaneous operation, in the same time that a single plank would be cut by one of the saws. We found that ten planks, each ten feet in length, were sawed in five minutes, one set of saws working through two feet of timber in a single minute.” The deals are afterwards transported by river or canal to seaports.

The Cutting and Transport of Canadian Timber.

The conveyance of timber to market in Canada is a very remarkable instance of commercial enterprise. While standing in the vast pine forests the timber-trees are common property: they acquire money-value only when the axe has been applied to them, and when they have been brought down to a shipping port.

The words lumber and lumbering, which convey no very definite idea to us, have in Canada and the United States a large and important meaning. Lumber is the general name for all kinds of timber, not only while growing in the form of stately trees, but after it is cut down, and even after it has been rudely fashioned into such pieces as may be convenient for shipment. So, in like measure, lumbering may be taken as a general name for all the operations whereby the timber is brought into a marketable state; including the cutting down of the trees; the conveyance to the saw-mills; the sawing them into boards, planks, joists, and other pieces; the forming them into rafts: and the navigating of these rafts down the creeks and rivers to the seaports. All the persons employed in these operations are designated lumberers; and they are subdivided into smaller groups according to the duties they undertake to perform.

As the practice of lumbering has been carried on for a great number of years, all the forests in the vicinity of seaports have been denuded of their trees: and the lumberers have therefore to go far inland to obtain their supply of timber. This occasions one circle of operations to last an entire year, from summer to summer. As the lumberers who dwell in the interior frequently carry on some other occupation, perhaps an agricultural one, they cut down trees in the forest just as it suits their convenience, during the summer and autumn. These trees are either hewn and shaped into balks and beams, or divided into shorter pieces, according as they are to be exported whole, or sawed up into boards and scantlings for the American or Canadian markets.

When a large supply of timber has been thus cut down, and the winter is so far advanced that snow lies on the ground, preparations are made for conveying the timber to some stream or river which flows down to a commercial port. On the banks of such streams saw-mills worked by water-power are erected, and these are employed for cutting up such of the “lumber” as is to be sold in the form of planks. The conveyance to the saw-mills and the operation of sawing occupy together the entire winter season. When snow is on the ground, a stout pair of oxen can drag a log from the forest to the saw-mill; and this method of transport is almost universally adopted, very few horses being employed in this way. Sometimes the saw-mills are constructed in a small creek near the forest, but in other cases they are lower down, on the banks of larger streams; and in this latter case the logs are floated down the smaller streams till they arrive at the larger one, where a dam or barrier is placed across the stream to prevent them from floating beyond the precincts of the saw-mill. The saws are circular in shape. Many of the mills have but one saw in operation; others have groups of parallel saws capable of cutting the log into eight or ten planks at once. Some of the smaller mills are built in so rude and rough a manner, that their cost does not exceed 30l. or 40l.; but if the mill lasts as long as the supply of timber in the neighbourhood, that is deemed sufficient, and a new mill is built when it is found advantageous to shift the quarters farther inland. A small mill with one saw, worked for twenty-four hours, will cut up three or four thousand superficial feet of timber. Men are employed to roll the logs along the gangways to a platform, and place them in a proper position to be acted on by the saw.

During the season of these operations the rivers and streams are frozen up; but in spring, when the melting of the ice renders them navigable, preparations are made for transporting the timber from the mills to the shipping ports. If the mill be on the banks of a small stream, the lumberers make up the logs and planks into rafts, the dimensions of which are suited to the capacity of the stream, and when these reach a larger stream into which the smaller one empties itself, the small rafts are broken up and re-arranged into larger ones; but if the mill be on the banks of the larger stream, the timber is at once made up into the rafts which float down to the shipping port—three or four hundred thousand feet of timber being sometimes conveyed in one raft. Sometimes the streams are too small to admit the rafts to float down them: and in such case they often lie aground for months, until an accidental flooding increases the body of water; or else they have to be broken up altogether, and other means adopted for conveying them to market. The rafts are generally put together very slightly, the value of labour being high, and the lumberers regulating the strength of the raft only in proportion to the distance which it has to float. This distance may vary from fifty to three or four hundred miles. Some one of the lumberers who may happen to be best acquainted with the stream acts as pilot, all the others following his directions in the navigation. The raft moves just as fast as the stream will convey it, be it slow or quick, no acceleration of speed being attempted by sails or oars; so that the time which elapses before the raft reaches its destination depends on many different circumstances. In some instances, where all the circumstances are favourable, the pilot navigates his cumbrous raft night and day without stopping; but if there are difficulties, he directs it into some cove or sheltered place during the night. The men are provided with long poles, by which they can regulate the position of the raft in the stream, keeping it either in the middle of the current or near the bank. The men seldom trouble themselves to make huts or cabins on the rafts: for the weather being spring, and it being optional to them to go on shore when they please, they make very few arrangements for their trip except in provisions. On the St. Lawrence, however, where the French Canadians bring down timber-rafts to Quebec for shipment, the men erect small huts or temporary dwellings on the rafts, since the voyage becomes of a more serious character.

When the rafts reach their destination, the lumber is sold, and the men share the proceeds according to the nature of their stake in the enterprise. This share is one entire year’s earnings, and the final disposal of the timber is therefore a matter of importance. The men then set out on foot to return to the interior, and as the distance they have to travel is sometimes three or four hundred miles, and the summer warmth has arrived, the journey is generally a fatiguing one. The men are not all fellow-labourers in an equal degree, for—as in almost every other kind of commercial enterprise—there must be some one to act as a capitalist, to feed the labourers while they are employed, or others who will supply necessaries in advance. There are storekeepers who purchase an annual supply of provisions, clothing, implements, &c., and retail them out to the lumberers on credit, to be paid for when the sales are effected in the spring, and when the mill-owner has been enabled to pay the wages of the men who felled, transported, and sawed the timber. If any unforeseen accident prevents the raft from reaching the shipping port in a saleable state, or if any other mishap occurs, the whole community share the loss.