Frontispiece Stoneware Made by the Author.

The Potter's Craft
A Practical Guide for the Studio and Workshop

By CHARLES F. BINNS

Director of the New York State School of Clay-Working and Ceramics ¶ Some time a Superintendent in the Royal Porcelain Works, Worcester, England

SECOND EDITION
SECOND PRINTING

26 PLATES AND 20 TEXT ILLUSTRATIONS

NEW YORK
D. VAN NOSTRAND COMPANY, Inc.
EIGHT WARREN STREET

Copyright, 1910, 1922
by
D. Van Nostrand Company

All rights reserved, including that of translation into the Scandinavian and other foreign languages.

Printed in the United States of America

LANCASTER PRESS, INC.
LANCASTER, PA.

"A book is written, not to multiply the voice merely, not to carry it merely, but to perpetuate it. The author has something to say which he perceives to be true and useful, or helpfully beautiful. So far as he knows, no one has yet said it; so far as he knows, no one else can say it. He is bound to say it clearly and melodiously if he may; clearly, at all events."

—Ruskin.

PREFACE TO SECOND EDITION

Since the publication of the first edition of this book eleven years have elapsed, years packed full of varied and interesting experiences.

During that time it has been the pleasant fortune of the author to conduct classes, especially summer classes, in the science and art of pottery production. These have been occasions of meeting many fine and noble personalities whom to know is a liberal education. As one of the consequences of these experiences the book has been revised and some new chapters have been written. Especial acknowledgments are due and are gratefully made to Elsie Binns for the chapter on Clay-Working for Children and to Maude Robinson for that on Alkaline Glazes.

The photographs are by the Taylor Studios, Hornell, N. Y.

C. F. B.

Alfred, New York.
March, 1922.

PREFACE TO FIRST EDITION

This Book is the outcome of an experience extending over a period of thirty-six years. Twenty years ago it would have been impossible, for the science of ceramics was not then born. Ten years ago it would have been wasted for the Artist-potter in America had not arrived, but now the individual workers are many and the science is well established.

Written teaching must be imperfect, but I have endeavored to set down the exact methods by which my students are taught, in the hope that those who cannot secure personal instruction may read and understand.

As far as possible didactic statements have been avoided and the attempt has been made to lead every student to experiment and to think for himself. In other words, I have tried to erect sign-posts and occasional warnings rather than to remove all obstacles from the road.

C. F. B.

Alfred, New York.
March, 1922.

CONTENTS

LIST OF PLATES

Frontispiece.—Stoneware made by the Author.

INTRODUCTION
The Present Need

Many times it has been proven, in the history of the world, that it is not possible to force a reform or a novelty upon an unwilling people. Such things are organic. In order to live they must grow and in order to grow must live. No attempt will be made, therefore, in these pages to foster an idea or propound a thought which may exist only in the predilection of the author.

The trend of the present demand, a persistent growth of several years, is towards a personal and individual expression in the crafts or industrial arts. This tendency is the natural swing of the pendulum from the machine-made product of the manufactory which in its turn was the inevitable result of mechanical invention.

When the artisan was an artist and the designer a craftsman, there was but a limited production of industrial art. The articles made were expensive and for the wealthy alone. The common utensils necessary to the household were made on the farm and were of the rudest possible character. But with the gradual development of machinery there came an abandonment of rural activities, a flocking to the city, manufacturing on a large scale, lower prices, and a huge output. This has, of course, taken many years to develop, but the utmost limit of the swing has been reached and the question is "What next?" Will the factory cease its labors? Will output decrease in bulk and improve in quality? Will there ever, in a word, be a return to medieval conditions? Not only may all these questions be answered in the negative but it may be stated with all sincerity that there is no need for any other answer.

What then, are not manufactured products as now put forth a menace to the art life of the nation? Are not the people being educated in the use of and belief in machine-made ornament and meretricious display? Perhaps so, but no good purpose will be served by a ruthless condemnation of these things. Art appreciation is a most subtle thing and no one may dictate to his neighbor as to what he should or should not admire. It took time for the public to understand and patronize the product of the machine even though the price was favorable. It will take time for an appreciation of craftsmanship to influence the land but this consummation will most assuredly come.

On the one hand there is the manufactory, teeming with "hands," riotous with wheels, turning out its wares by the thousand and supplying the demand of the many; on the other, there is the artist-artisan. He labors at his bench in sincere devotion to his chosen vocation. His work is laborious and exacting, he can make but a few things and for them he must ask a price relatively high. Both these conditions are necessary. The craftsman cannot supply the need of the people and the manufacturer has no time or thought for disinterested production. Herein lies the need and here is the mission of the individual worker.

In every age it is given to some to discern more than the multitude and it is theirs to teach. The people are anxious to learn, are eager to be led. What they demand will be manufactured and so by the irresistible lever of public opinion the man at the bench, if he be true to himself and to his craft, may move the millionaire manufacturer to make wares which, if not truly artistic, shall at least be inoffensive. Such a mission is not to be accomplished without suffering. The man who essays to attack a giant must be sure both of his ground and of his personal condition. He who would establish his craft in the knowledge and affection of men must possess enthusiasm, skill, discrimination and infinite patience.

It is not enough to discern the good, the hand must follow the brain with diligent care. Furthermore, it is not enough to be able to make things well, one must also make them good and know it. The artist-artisan must have courage to destroy that which is below standard, and self-denial to resist the temptation to sell an unworthy product.

The country needs craftsmen of this type and for them there is an important work. For such, if they elect to join the ranks of the potters, these words are written and in the hope that some may be stimulated, encouraged, guided and helped the counsel of a fellow craftsman is offered.

CHAPTER I
Applied Art

It is not intended, in these lines, to consider what are generally termed the Fine Arts, painting and sculpture. These are perfectly competent to take care of themselves and, indeed, the author can make no claim to an ability to discuss them. In the field of applied art, however, there are certain principles to be observed, principles, moreover, which are frequently lost sight of because of the lamentable separation of the functions of the artist and artificer.

It is extremely difficult to draw the line between art and manufacture. For example, a wall paper, designed with skill and executed by machinery in actual reproduction of the work of the designer; is it a work of art or is it a product of the factory? It is both. Primarily a work of art is the product of the artist's own hand. It reveals his individuality. It is the language in which he expresses himself to his audience. It is the note of his voice. Such a work may or may not appeal to a large section of the public. This will always be so. An artist, be he poet, musician, painter or craftsman, is one who can see more than others. What he sees he endeavors to express but it is inevitable that he be sometimes misunderstood. Hence it the more necessary that his message be delivered at first hand. To look upon a replica of the work of an artist is like reading a sermon or an oration from a printed page. One may gather much of the teaching but the personal note, the tone and gesture, must be lost.

But there are many who can gather the words of great men only from books. There are, moreover, books which have never been spoken and wherein alone the message is to be found. In like manner there are works, emanating from the hand of great designers which can only be made available for the many in a form of reproduction. The wall paper cited as an illustration is of this class. Were it not for the printing press this beautiful design could not have passed beyond the studio, and while it is a great thing if a wealthy man can commission a Whistler to decorate a peacock room, it is an advantage by no means to be ignored that a well designed wall paper can be purchased by the piece.

But while this is true of such of the household goods as cannot be procured except by the medium of the machine, there are other examples. In the case of the wall paper the function of the machine is simply to transfer the proper design to the paper itself. This has no identity except as a surface. It is no more to be considered than is a canvas upon which a picture is painted. But when a chair or a table is formed out of pieces of lumber uniformly shaped by one machine, the seat or top put together by another and the legs or back carved or stamped by a third, art or individuality is lost because mechanical construction is involved.

Still more is this the case in the product of the manufactory of pottery. In commercial practice not only is a shape designed without regard to decoration but the same decoration is placed upon several forms, or a single form is made to suffer as the vehicle for many decorations. Some of the results may be pleasing, even beautiful, but it is more by luck than guidance and no piece produced in this way has any claim to be classed as a work of art.

On the other hand it may happen that a work of art, in the sense of individual expression, may not even be beautiful and one is tempted to ask the reason. If a work which is a genuine expression of a man's personality fail to please the senses of those who are trained in the finer perceptions there must be something wrong.

If the adverse opinion be at all general amongst the critics it may be assumed that they are right and that the worker is wrong.

For example, the form of a flower is not a fit receptacle for a . It often happens that a designer, struck with the beauty of, say, a tulip, has modeled the flower in clay and made it into a candlestick. Now it is obvious that the more closely the model simulates the flower the less appropriate it is for such a purpose. If the model be heavy enough to be of use it must be far removed from its prototype. If a conventional design for a candlestick be adopted the petals of a flower may be shown in relief upon it but there must always be a solid foundation to account for the possibility of use.

A favorite form with some designers is a bird's nest made into a flower holder. In this the same criticism applies. A bird's nest is always built to let water escape. Even a mud-lined nest is not impervious and the idea is obviously inappropriate. It is important that imitation be avoided and especially the imitation of material. One often hears the remark "How beautiful, it looks just like bronze." This, of course, comes from the casual observer to whom the skill of the imitation appeals but it cannot be too strongly insisted upon that to imitate one material in another is false from every point of view. Nor is it necessary. Clay is sufficient in itself. There are so many effects possible in pottery which are not possible in any other medium that it is entirely superfluous to seek outlandish texture and color. To be sure, such things are popular but that does not make them sound in principle or true in taste.

It should not be a purpose of any craft to make pieces merely as an exhibition of skill. This is done sometimes by such versatile workers as the Japanese, but it may be laid down as a law that a production of the nature of a tour-de-force, an object which simply excites wonder at the skill of the worker, is undignified and meretricious. It is akin to the work of certain painters who delight in painting marble or velvet so as to exhibit a perfect texture only and is but one degree removed from the skill of the pavement artist who with colored chalk draws a lamb chop or a banana in such a manner that the real article seems to be lying on the ground at his feet.

The true artist, be he potter or painter, works primarily for his own satisfaction. It sometimes happens that a defect, not large enough to be obvious, is a temptation to concealment. The public will never know. But the consciousness of the existence of such a blemish will destroy the pride of achievement which should accompany every finished piece.

If the worker aims to draw any expression of opinion from the untrained observer it should be in the nature of a remark on how easy the work looks. Art will always conceal effort. Just as the poet or orator is at his best when he clothes sublime thought in simple words so the artist or craftsman glorifies his vocation when he makes use of means which appear to be within the reach of every observer.

In addition to the work of the producer there must be considered the function of the critic. Artists are commonly impatient of criticism. Tennyson voiced this sentiment when he wrote of "Irresponsible indolent reviewers," but the power of the critic is rarer than the skill of the craftsman. True, there are critics and critics. There is the man who knows what he likes and who cannot be persuaded that he likes what is false, and there is the trained critic who sees with an educated eye and dissects with an unerring word. It is not common to find critic and craftsman in one and the same person and it not infrequently happens that the persons exercising these functions are at variance with each other.

But if the critic be correct why is the craftsman wrong? In this let it be presumed that there is nothing wrong with his craft as such; that he handles his tools skilfully and has perfect control over his material. More than this, however, is necessary. The first requirement is a sense of form, a term which includes outline, proportion and structure. Often and often it is found that a designer depends upon novelty alone for acceptance. He is not altogether to blame in this for the great American public will, more often than not, ask, "Is it new?"

Novelty in itself is no claim to consideration; in fact, on being shown some product of which it is said "Nothing like it has ever been seen before," the temptation is great to respond, "May its like never be seen again." Novelty apart, form must possess proportion, balance and grace. A chair must invite the sitter, a vase must stand securely, a carpet must lie flat. The absence of these things may evidence an individuality on the part of the designer but it is art at the expense of truth.

The second necessary condition is fitness which again is expressed in several ways. A porcelain vase is required to be light, graceful and refined. A piece of ruder pottery may be no less satisfactory if it exhibit vigor, strength and solidity. A large pot for a growing tree is, for these reasons, more appropriate in grès than in porcelain. Porcelain is translucent but such a quality is of no advantage in the case of a flower pot; the strength of a massive body is, however, demanded by the circumstances of use and hence the unfitness of the one and the fitness of the other.

Another point of fitness is concerned in the correspondence between size, form and weight. It often happens that one takes hold of a piece of pottery and experiences a shock. The mind unconsciously forms an estimate of what the weight will be but the piece does not respond. The effort put forth in accordance with the appearance of the object either lifts it suddenly into the air or fails to raise it from the table. The artist critic takes note of these things. To handle his wares is a constant pleasure, for one is not continually disappointed by unexpected violences. This correspondence or equilibrium is apart from the use of a piece of pottery. It is quite as legitimate to express one's ideas in clay in the presentation of simple beauty as it is to express them with paint upon canvas. At the same time there is always a satisfaction in a vase or flower pot that it can be used if required. Thus a vase which will not hold water is technically imperfect and the bête noire of the conscientious potter.

It is in the harmony of these things that the rôle of the critic is seen to advantage. If the artist be capable of criticizing his own work he is in a position to command attention but he must either discipline himself or be disciplined by others, which, after all, is the way of the world at large.

CHAPTER II
Pottery

It must always be an open question how much credit for artistic feeling can be given to primitive races. The production of pottery was, at first, the supplying of a need. Clay offered a medium for the making of household utensils which were at once fireproof and impervious. The work does not belong strictly to the earliest stages of civilization but is a development of advancing refinement.[A]

Crude and unprepared clays were used for the most part but the makers could scarcely have been conscious of the charming color-play produced by the burning of a red clay in a smoky fire. The pottery of the Indians is artistic in the sense of being an expression of an indigenous art and much of it is beautiful, though whether the makers possessed any real appreciation of beauty is open to doubt.

The pottery was exclusively the work of the women. No wheel was employed but the ware was mainly constructed by coiling. Long strips of clay were rolled under the hands and made of uniform size and these were then coiled in spiral form, the rolls being welded together with water. After proceeding a certain height the walls of the growing jar would become weak under their own weight. The piece would then be set aside to undergo a partial hardening upon which the work would be carried forward another stage. The shape being completed and partially dried, the maker would work over the whole surface with stones or simple tools until the marks of the coils had disappeared and the walls had reached a sufficient thinness. A great deal of skill was exercised in accomplishing this.

Many of the Indian forms are transitional. The basket, the gourd and the bark-made jar suggested their shapes to the potter; indeed it is sometimes evident that clay vessels were constructed as linings to wicker forms, the outer layer of twigs being afterwards burned off. The firing was performed in the open flame without any protection, a fact which accounts for the great irregularity found in quality and color.

The decorations used by the Indian women were of the type common to unglazed wares. The clay was incised or embossed and natural earths were used as pigments. This accounts in great measure for the fitness which may be observed in aboriginal decoration. There is an absence of artificial coloring, nor is there any straining after effect, but instead there is shown a sober strength and a sane expression of values which would do credit to a modern designer.

America is fortunate in possessing abundant relics of primitive times but it cannot be doubted that in other lands similar work was done, making allowance, of course, for the characteristic variations in national traits. The potter's craft is of such a nature, using an omnipresent material and requiring the minimum of tools, that almost every nation on the globe has practiced it. In some it has never been developed beyond the narrow limits of the stone age, in others it has reached the utmost perfection of cultured skill.

For perfection of quality in crude pottery, no ware has ever surpassed that of Greece. It is not practicable here to deal with the numerous branches and sub-branches of Greek pottery; let it suffice for the present purpose to speak of only two main groups. In the first, the background of the decoration was supplied by the tint of the bare clay; in the second, this tint afforded the color of the decoration itself, the background being covered with a black pigment. To speak briefly these groups are known as black-figured and red-figured wares.

The wheel was early adopted by the Grecian potters as a means of producing form and although molds were sometimes used, the wheel was, to all intents and purposes, the sole method of manufacture. Greek pottery is once fired. Birch classes it as glazed terra cotta, but the glaze is nothing more than the black pigment with which the decoration is carried out. The uncolored part of the clay is not glazed but polished with a hard tool. Probably some famous potters employed assistants either to make the pieces or to decorate but it does not appear that there was any reproduction, at least, during the best period. At first primitive ideas prevailed. Geometric designs were succeeded by rhythmic friezes of beasts and birds done in black. When the human figure made its appearance the faces were all in profile with full-fronting eye while the prominent details of feature and drapery were scratched with a sharp point before burning.

The change of method to red on black gave much wider scope for the treatment of the human figure, rendered a fuller expression possible and enlarged the power of pictorial action. Great skill in drawing was manifested and details of both drapery and features were expressed with great care by means of the brush.

Such was the state of the art when the decadence set in and the work fell into the hands of plagiarists and charlatans. Meretricious coloring and gaudy ornament succeeded the refinement and restraint of the earlier days and so the art perished.

To the inventive power of the Romans the ceramic art owes more than one novelty. It would appear that the desideratum of the early days was a black ware. Homer in his hymn wrote:

"Pay me my price, potters, and I will sing.
Attend, O Pallas, and with lifted arm protect their ovens,
Let all their cups and sacred vessels blacken well
And baked with good success yield them
Both fair renown and profit."

The Greeks accomplished this blackening by means of a pigment, the Romans secured a similar result by a manipulation of the fire.

It is well known that the oxide of iron which imparts to the clay a red color will, if burned in what is known as a "reducing" fire, turn black. This is accomplished by keeping the air supply at the lowest possible point and the effect is heightened by the smoke which is partly absorbed by the clay. This black ware is known as Upchurch pottery from the name of a locality in England where large quantities have been found, but numerous examples occur in Germany and, indeed, wherever the Roman hosts encamped.

A second type of pottery is called Castor ware and consists of a dark clay upon which the decoration is traced in clay of a lighter color. The decoration was applied as a slip or cream and hence was the forerunner of the modern slip painting or pâte-sur-pâte. This ware is well worth a study. The decorations consisted largely of conventional borders and panels but it is specially notable on account of the free use of motives drawn from daily life. One of the commonest scenes depicted is the hunt of hare or stag, the animals and trees being often woven into an almost conventional frieze.

The most valued type of Roman pottery seems to have been the Aretine or Samian ware. This is a bright red color and possesses an extremely thin glaze. A particular clay was evidently used, but all knowledge of its source has been lost.

With the importation of Chinese porcelain by the Dutch the whole trend of pottery manufacture was changed. No longer was black a desirable color, white was seen to be much more delicate and beautiful and henceforth the endeavor of the potter was to produce a ware which should be as nearly like porcelain as possible. The crudeness of the clay kept this ideal from being realized, but various expedients were adopted and gradually better results were obtained.

Throughout the East a type of white pottery was made which, though stimulated by the Chinese example, may have been a relic of the knowledge of the Egyptians. A crude clay was coated with a white preparation, possibly ground quartz, and upon this there were painted conventional designs in sombre colors. A clear glaze covered the whole and imparted to the colors a beautiful quality as of pebbles under water. The nature of the glaze is made evident by the hues assumed by the metallic oxides employed as colorants. Copper oxide affords a turquoise blue, manganese, a wine purple, and iron, a brick red. If the glaze had contained any considerable amount of lead oxide, these colors would have been quite different; copper would have produced green, manganese, dark brown, and iron, yellowish brown. The iron pigment was evidently a clay, sometimes spoken of as Armenian bole. The red color is always in raised masses because if a thin wash had been used the color would have yielded to the action of the glaze.

This ware, commonly called Oriental engobe ware, affords a fruitful study. Effects similar in character were produced by the late Theodore Deck of Paris, but no considerable use of the ancient methods has ever been attempted.

The use of tin and lead in glazing was known to the Arabian and Moorish potters but these ingredients were not abundant in the East. When, however, the Moorish hosts conquered a part of Spain in the twelfth century it was found that both lead and tin were available. The result was the development of the enameled ware known by the generic name Maiolica. Some have maintained that this was first made in Italy but the name is derived from the island of Maiorca from which much of the pottery was exported. The famous Alhambra vase remains as a monument to the skill of the Hispano-Moresque craftsmen, but it was the Italian artists of the Renaissance who brought the enameled wares to perfection. The interest here is artistic and technical rather than historical, but no one can study the work of the period without learning something of Luca della Robbia and Giorgio Andreoli, of Gubbio and Pesaro and Castel Durante.

The use of lead in the glaze proved seductive. It simplified the technical problems and provided a brilliant surface but alas! the colors suffered and one by one they succumbed. The blue of cobalt, however, proved indestructible and so, when the technical knowledge of the South met the traditions borrowed from the Chinese, there was born, in the little town of Delft in Holland, the blue enameled ware which has ever since been known by the name of its native place.

As to the technical details of the production of Delft ware a great deal of information is available. The clay used contained a goodly proportion of lime and this served to hold the enamel in perfect union with the body. The decoration was painted in cobalt blue upon the unburned surface of the enamel. This was, in a measure, courting a difficulty but it is the glory of the craft that a difficulty is cheerfully accepted if in the overcoming there is found success. If the Delft potters had burned their enamel in order to make the painting easy, the world would never have enjoyed the tender tone of blue for which this pottery is famous. By painting the blue color over the powdery enamel, a more perfect union of enamel and color was accomplished than would have been possible by any other means. This fact alone is sufficient to account for the unsatisfactory nature of the modern, so-called, Delft. Difficulties have been avoided rather than met and the success of the early masters has eluded their recent followers.

Much of the pottery made in France in the seventeenth century was inspired by the Italian renaissance. In fact the word faience is due to the avowed intention of the manufacturers of Nevers to copy the enameled pottery of Faenza. Almost the only novelty of the time was the inversion, by the Nevers potters, of the Delft idea. Instead of a white enamel with a blue decoration they used, in part, a blue ground with a decoration in white. It is not known that this variation found acceptance in any other place but in many localities, notably at Rouen, the manufacture of enameled wares was pursued with great success. The only real difference between the wares of Spain, Italy and France, lies in the decorative treatment. Sometimes the emphasis was laid upon lustres, sometimes on blue and white and again upon polychrome painting. In one place there was an extensive use made of pictorial treatment, in another all was conventional. The differences are interesting to a student or a collector but to the craftsman enameled pottery affords but one, though by no means an unimportant, means of expression.

France, however, gave birth to two important and interesting departures from the beaten track; the so-called Henri deux ware, and the faience of Bernard Palissy. Important as these are to the ceramist, it is a remarkable fact that neither of them had any appreciable influence upon the art as a whole nor did they leave any descendants.

A good deal of controversy has raged around the pottery commonly known as Henri II, some authorities claiming that it should be called Faience d'Oiron, and others assigning to it the name Saint Porchaire. It was, quite evidently, the production of an individual or group of individuals who had no connection with ordinary pottery manufacture, and the small quantity produced is evidence that it was made for personal pleasure. The name Henri II is undoubtedly satisfactory, for it was made in the reign of the second Henry and some pieces bear the monogram of the king. On the other hand H may be the initial of Helene d'Hengest, who occupied the chateau d'Oiron and who had in her employ one Bernard who filled the position of librarian. The style of the work seems to indicate a devotion to books, for the patterns are suggestive of book-binding tool work but were not produced in the same way. The ware was made of a natural cream-colored clay and the shapes were modeled with great skill. Upon the plain surface patterns were tooled or incised and the hollows thus formed were filled in with dark-colored clays. The whole was then covered with a clear lead glaze which afforded a finish very much like modern earthenware.

The origin of this work is a matter of little more than academic interest but the technical details are of such importance as to be well worth a study. The ware is original and unique. No pottery either before or since has approached it in method, and the quality of most of the pieces is all that could be desired. Such was the elaboration of detail that no price could have been set upon the ware and it was evidently not made for sale. A distinct growth in style can be traced. The first pieces were somewhat archaic and even crude but as skill was acquired greater perfection was attained. As is too often the case, however, the skillful hand overreached itself and the later pieces are loaded with meretricious detail in many colors. There are only about fifty pieces known and these are equally divided between the museums of France and England.

Bernard Palissy was a versatile genius but is here only considered as a potter. He states in his records that he was inspired by seeing an enameled cup. It was at one time supposed that this cup was of Italian maiolica but later authorities incline to the belief that it was a piece of Chinese porcelain which Palissy supposed to have been enameled. No white clay was known to him but enameled wares were quite accessible. It can scarcely be believed that maiolica was a novelty but it can easily be understood that a piece of white porcelain, viewed in the light of the contemporary knowledge of enamels, would appear of marvellous quality.

Palissy essayed to imitate this wonder but attacked the problem from the standpoint of an opaque glaze. He spent fifteen years in experimenting but never realized his ideal. He did, however, produce a palette of marvellous colored enamels. He was a close student of nature and modeled all kinds of natural objects, glazing them in the proper hues. He also designed and made vases and service pieces, some with figure embossments. The story of his struggles is readily accessible to any who are interested.

Palissy left little or no impression upon the ceramic art of his time but in recent years some work has been done in colored glazes fusible at a low temperature. This ware is sometimes sold under the name of maiolica but it is more nearly an imitation of Palissy. The main difference between the two types is that while the maiolica or tin-glazed pottery of Spain, Italy and France consisted for the most part of a white enameled surface upon which painting was applied, Palissy used little or no white enamel but decorated his wares with tinted glazes which themselves supplied the colors.

In the low countries and the German states there was made the striking and original pottery known as Grès de Flandres. The clay was of the type commonly used for the manufacture of stone-ware and appears in three colors, brown, gray and cream. The ware was made on the wheel and embossments more or less elaborate were subsequently added. The unique feature consisted in the method of applying the glaze. This was simply common salt, thrown into the heated kiln and volatilized. The salt vapor bathed the glowing pottery and combined with its substance, thus producing the delightful orange-skin texture known as salt glaze.

The knowledge of this method was conveyed to England in the seventeenth century and gained wide acceptance there. The English potters preferred to use clays which were almost white, and after glazing a decoration in brilliant colors was sometimes added. Naturalistic treatment was not attempted but conventionalized subjects were used with almost the effect of jewelry. The temperature at which this work can be produced varies with the clay. Many fusible clays will take a salt glaze but the beauty of the product depends to a large extent upon the purity of the body. This necessitates a hard fire, for white-burning clays always need a high temperature for vitrification. The early potteries of England were dependent largely upon clay effects. Some little enameled ware was made and is known as English Delft; but the bulk of the work was slip painted, incised, marbled or embossed. Each of these methods is capable of an intelligent application and all are within the reach of the artist potter.

CHAPTER III
Porcelain

The production of porcelain is the goal of the potter. The pure white of the clay and the possibility of unlimited fire treatment exert a profound influence upon the imagination while the difficulties of manipulation only serve to stimulate the energy of the enthusiast. For present purposes not much is to be learned from the soft porcelains of France nor from the bone china of England. German and French hard porcelain are but developments of the Chinese idea and therefore need not be studied apart from their prototype.

The earliest date of Chinese porcelain is unknown. The records of the nation are very ancient but their meaning is often obscured by the fact that in the Chinese language the same word was used of old to denote both porcelain and earthenware. Specimens dating from only the tenth century A. D. look almost incredibly old. They are coarse and heavy in structure but are aglow with vibrant color. The finest porcelains date from the fourteenth and fifteenth centuries and these are the ideals towards which every modern potter looks.

Broadly it may be stated that two methods prevailed. In the former the glaze itself was charged with color or the coloring matter was applied to the clay beneath the glaze. In the latter the porcelain was finished as to body and glaze and the decoration was applied at a subsequent and much lighter burn.

The first named class is called single-colored porcelain; the second has several names such as the famille rose and famille verte as defined by Jacquemart.

In the single-color class it is evident that the potters were not at all sure of their results. In many museums there are to be found examples of ox-blood red, more or less fine, and, with them, other pieces which were intended to be red but which failed in the fire. The wonder is, in these cases, that the pieces, even though failures, are beautiful. The knowledge required for the production of these wares is largely scientific; at the same time it is not to be believed that the Chinese had any special scientific training. They evidently traveled a long and tortuous path before the goal was reached, in fact, they often fell short of it altogether, but they had plenty of time and unlimited patience. The modern potter is, if less patient, more fortunate in that the course has been marked out with more or less accuracy and, if the landmarks of science be heeded, a certain degree of success may be attained.

This single-color work is the true field of the ceramist. Anyone possessing the power of using a pencil, and with a large stock of patience, may produce over-glaze decoration, but to prepare glazes of many hues and to consign them unprotected to the fury of the furnace, requires skill, patience, courage and enthusiasm.

During the last twenty years a new school has arisen which combines in a measure the advantages of the two Chinese methods. Colors are prepared from refractory materials and upon clay or soft burned biscuit ware, scenes, in more or less conventional form, are painted, or else a design purely conventional in character is applied by the artist. The ware is then glazed and subjected to the severe fire which all porcelain undergoes. The result is that the porcelain and the painting are united in a sense that can never be the case with over-glaze treatment. The colors become part of a purely ceramic unit; the spirit of the artist is fixed by the fire.

To this class belong the porcelain of Copenhagen and the recent product of Sevres. These, of course, represent the result of much arduous training and many tedious experiments. Both the training and the experiments are necessary to some extent for every worker, not only because pottery clays vary much in composition, but because individuality can only be obtained by the preparation, in the laboratory, of the desired compounds.

The Chinese, doubtless, stumbled upon many of their successes by accident, helped by the fact that the character of the fire employed influenced many of their colors. This will be explained in a later chapter. They were, however, quick to seize upon that which was good. Many fanciful names were given to the rarest colors, such as "the violet of wild apples," "liquid dawn" and "the red of the bean blossom." This idea has been carried further in France by the invention of such names as "Sang-de-boeuf," "Sang-de-poulet," "clair-de-lune," etc., and pursued in this country in "Peach blow."

In the over-glaze treatment, the type named "famille verte" is characterized by a clear green glaze or enamel over a design in black. The whole is painted over the porcelain glaze and the green enamel is so soft that it is often decomposed on the surface. When a broad black mass is covered with green the decomposition gives rise to prismatic colors and occasions the term "raven's wing black." Some of this ware has also been gilt but the gold lines have disappeared and can only be located by the slight dullness of the enamel where they once were. Well known to collectors also are the rose-back plates. These belong to the "famille rose" in which the characteristic note is a delicate rose pink. This color is prepared from gold and when it is placed upon the back of an egg-shell plate a tender rosy transparency is imparted to the piece. One of the best known of the single colors is the pale sea green named celadon by the French. This color in China was called "the sky after rain" and was considered both rare and valuable.

The porcelain of Copenhagen is the product of scientific skill and artistic taste. In the studios attached to the Royal Manufactory there has grown up a tradition of work and criticism which is fostered by ladies of birth and position. Many of these paint upon the porcelain themselves and so constitute a school which has become world famous.

Natural objects are, for the most part, chosen and, as the palette of colors is, owing to the intense fire, quite limited and low in key, a tone of quiet atmosphere pervades the painting. This is accentuated by the use of the air-brush to distribute a ground color upon the ware in graduated strength.

At the National Manufactory of Sevres there has been some attempt to follow the Copenhagen method but to a greater extent the work is along the lines of conventionalized form. In this treatment the French artists excel, being wonderfully accurate—almost too accurate—in their lines and spacing. Several individual workers in France have also pursued this plan, designing and executing the pieces which have made the French artist-potters famous.

In the porcelains of Berlin the quality lies largely in the complete mastery of technical details. The work is, as would be expected, German in style, but the paste is pure and the colors are well prepared.

From this brief review it will be seen that the interest in the manufacture of porcelain lies not so much in variety as in the value of individual results. In the pottery described in the previous chapter a great many different clays were used and each one proved suggestive to the potter. In porcelain, on the other hand, the body clay is almost identical wherever prepared, the requirement of a white translucent paste being paramount.

CHAPTER IV
The Nature and Properties of Clay

Clay differs from earth or soil in that it possesses certain characteristics which these do not possess. Its distribution is very wide but for the most part it lies concealed from view. In certain parts of the country it is so abundant that it breaks through the surface or is exposed as an outcrop but usually it is covered by the soil which supports vegetation. Unless the subsoil consists of sand it is easy to expose a clay by plowing or digging with a spade. It usually appears as a greenish or bluish substance of close and uniform structure. The texture is sometimes smooth but more often numerous small stones are found imbedded in the mass. Such clays as are commonly found can be used for the manufacture of some kind of pottery but in the great majority of cases the ware will be red when fired because the clay contains a proportion of oxide of iron. A pure clay does not contain this and therefore becomes white or nearly white in the kiln.

Pure clay, known as clay base or clay substance forms a part of all natural clays though sometimes only a small part. It consists of silica, alumina and water in a state of combination and is thus known as a hydrous aluminium silicate. While this substance is very common as an ingredient of ordinary clay, it is rarely found alone or uncontaminated. Commercial or workable clays may be said to consist of clay base and sand, with or without other impurities such as lime and oxide of iron. For working purposes it may be granted that the potter has to deal with a mixture of clay and sand. But sand is not a definite expression. It may vary both physically and chemically within wide limits. The physical nature has to do with condition, the chemical with composition. Thus a sand may be almost as coarse as gravel or as fine as the clay itself. It may be a pure quartz sand or it may be a crushed rock of almost any composition. The former is known as quartz, the latter as feldspar or feldspathic sand because it approaches in composition the group of minerals known as feldspars. Each of these ingredients, clay, quartz and feldspar, has an important part to play in the transformation of clay into pottery. Few of the clays used in making white pottery possess these ingredients in the correct proportions so that it becomes necessary to make a mixture in which the necessary proportions will be found.

For successful pottery making three properties are demanded in a clay. First, plasticity. Without this, clay could not be shaped at all. It constitutes the obedience of a clay to the forming influence whether hand or mold. The necessity for this quality may be illustrated by the proverb "Making ropes of sand" as an example of the impossible. Sand, possessing no plasticity, cannot be shaped or made to hold together.

The second property is porosity. A clay which exhibits a high degree of plasticity can be easily shaped but it cannot be safely dried. The water of plasticity cannot escape and therefore the clay warps and cracks. The function of porosity is to prevent this. A porous clay permits the water to escape freely and the clay can be dried without damage. This condition is produced by the admixture of sand or by the presence of sand in a natural clay. A coarse sand is more effective than a fine sand but a sand that is too coarse will interfere with delicate working while a sand that is too fine approximates the action of the clay itself and produces a substance which is dense rather than porous. Porosity is therefore the reverse of plasticity and these two properties must be adjusted so as to balance each other.

The third necessary property is commonly known as vitrification but could be better named "densification" because complete vitrification is not attained in ordinary clay wares. This property may be defined as that which causes a clay to yield to the action of a high temperature so that the result is a ware, more or less dense, which is hard, durable and sonorous. With this there must be coupled a certain amount of resistance to heat treatment so that the pottery does not fuse or collapse during the firing. Here also is found the need for adjustment. The clay must yield to the fire but not completely. It must resist but not entirely.

Plasticity is due to the clay base. Not only to its quantity but to its quality also. Some forms of clay in which clay base predominates are not plastic because the clay base itself is coarse grained. Other forms with less clay base present are plastic because this ingredient is fine grained and tough. Pure clay base is also highly resistant to fire and therefore contributes to the refractoriness of the mass.

Porosity is caused by the sand in the clay. Any kind of sand will produce porosity but the effect differs with the condition of the sand. Coarse sand is more effective than fine sand. More sand will, of course, cause greater porosity.

Vitrification or densification is due to the feldspar or fusible sand. This also varies with the condition. A fine-grained feldspar will produce vitrification more easily than the same amount of coarse feldspar.

Certain substances are available for use in pottery mixtures, which possess one or other of the necessary properties in high degree so that they will impart these properties to a mass to which they are added.

Kaolin or china clay is usually fine, white, and refractory. Some kaolins are rather plastic but most of them are "short" in working and rather tender. For the production of a white ware kaolin is indispensable. No other ingredient will afford the pure white color which is sought after in porcelain and china.

Ball clay is very plastic, easily vitrified, but is not white. The color varies from a cream to a gray. The use of a ball clay is therefore limited in white wares because it will spoil the color. For wares in which a light cream color is not objectionable ball clays are valuable and almost indispensable.

Stoneware clay is usually a rather plastic clay which contains a good deal of sand, hence stoneware clays can be used for certain classes of ware without admixture. A rather high temperature is required for most of these clays, though occasionally one can be found which will become dense at the fire of a studio kiln. The clays sold by the Enfield Pottery Company and by the Western Stoneware Company are of this type.

Ground flint is a necessary ingredient in almost all pottery. It aids in the porosity of the clay and enables the mixture to be adjusted to fit a special glaze.

Ground feldspar is also necessary. Like flint it aids in the porosity of the unburned clay but unlike flint it produces density in the firing.

By a proper adjustment of these ingredients a clay can be composed which will meet the special requirements of the worker.

In order to ascertain the properties of any given clay certain simple tests may be made and every clay-worker should know how to do this because one cannot be too well informed as to the materials to be used.

First, water of plasticity. A certain portion of the clay, dried and powdered, is weighed out. It is convenient to weigh in grams and to measure in cubic centimeters because in this way calculation is easy. The scales and weights are described in the chapter on glazes. For measuring the water a glass vessel called a graduate is used. One holding a hundred cubic centimeters and graduated in centimeters and tenths can be obtained from a dealer in chemical supplies. One hundred grams of clay is weighed out and transferred to a glass slab. The graduate is filled with water to the one hundred mark. Some of this water is then poured on to the clay, adding little by little as needed until the whole can be worked into a stiff mass of the proper plasticity. The quantity of water used is then carefully noted by observing how much is left in the graduate. Suppose, for instance, 70 cubic centimeters are found remaining, the hundred grams of clay has absorbed thirty c.c. of water and as one c.c. of water weighs one gram the clay has taken just 30 per cent. This amount is important because it is one of the best indications of plasticity. A very plastic clay may need 40 per cent, a non-plastic clay may be satisfied with 25 per cent.

Second, shrinkage. The mass of plastic clay is now transferred to a plaster bat and rolled or pressed out into a smooth slab about 12 centimeters long. Here again the centimeter is used in preference to the inch as being more easily calculated. A faint line is ruled on the clay slab and two fine scratches are marked exactly ten centimeters apart. The edges are trimmed and the excess clay made up into three or four small pieces which are to be fired in different parts of the kiln as tests for density. When the clay slab is dry the distance between the marks is measured and noted. The ten centimeters being divided into one hundred millimeters, each millimeter of shrinkage means one per cent. After firing, a second measurement is made and the differences are noted as dry shrinkage and fire shrinkage respectively.

Third, firing. The slab with the measurement upon it is set in the kiln in the place where the clay wares are to receive the first or biscuit fire and the small pieces are arranged in different places so as to secure as many different conditions as possible. The position of each should be carefully recorded. After firing, the marks on the slab are measured as already described and note is taken of any warping of the piece. The color is also recorded. The small pieces should be tested for porosity or absorption of water but this is rather a delicate operation and needs a particularly sensitive balance. Generally it will suffice to use a wet sponge or to dip each piece into water, removing it quickly and noting carefully the rate of speed at which the water is absorbed. If the water should be scarcely absorbed at all a line of ink may be drawn upon the pottery with a pen, the piece being perfectly dry. In a fully vitrified ware the ink can be washed off, leaving scarcely a mark but the test is quite sensitive and with a little practice will afford an excellent means of comparing the density of different clays or of the same clay at different temperatures.

Fourth, glazing. It is well to have ready a small supply of a standard clear glaze. Each of the test pieces should be covered with this in a rather thin coat and then they should all be fired again, this time close together so that they will receive the same heat treatment. This will enable one to determine what degree of fire for the clay will best suit the glaze.

CHAPTER V
The Preparation of the Clay

A clay having been selected in accordance with the tests described, it becomes necessary to prepare it for use. A fairly large supply should be obtained and stored in a dry place. Most natural clays need some kind of cleansing for there are almost always foreign substances present. This cleansing is accomplished by reducing the clay to the fluid known as slip. The necessary appliances for making slip are as follows:

• A large sieve of quarter-inch mesh.
• A small wire sieve of about 14 meshes to the inch.
• A large barrel.
• Two galvanized pails.

The clay is, after drying, powdered and sifted through the large sieve. One of the pails is half filled with clean water and the clay, handful by handful, is sprinkled into it. The clay rapidly absorbs the water and sinks to the bottom. The addition of clay is continued until a small mound rises through the water, when the whole is left to soak for an hour. The bared arm is then plunged into the pail and the mass stirred vigorously. A stick or paddle will serve, of course, but the potter learns a great deal by the feel of the clay and therefore the hand is best. It is said that he is a poor sailor who will not dip his hands in the tar bucket and in like manner, he is a poor potter who fears the slip tub. This stirring will tell a good deal about the probable working of the clay. It may be stony or sandy or greasy. The large stones and roots will have been removed by the sieve but now, after thorough mixing, the slip is poured through the small sieve into the barrel. Both pails may be kept going at once, one being filled while the other is soaking and so on until the barrel is full or, at least, a good quantity of slip has been prepared.

If the clay prove very sandy it should be washed. The mixture in the pail having been well stirred is allowed to stand for a definite time, say one minute. The slip is then poured into the second pail and it will be found that a quantity of sand has settled. This is thrown away and the slip in the second pail is examined. If enough sand has been removed, the slip may be poured into the barrel, using the fine sieve as already described. If still sandy the process should be repeated, the settling being for two minutes. Experience is the best guide in this operation but all the sand should not be removed.

When the barrel is full of slip it is allowed to stand over night when some inches of clear water will be found at the top. This is removed with a siphon which may be made of a piece of lead or rubber pipe. The removal of the water results in the thickening of the slip and the contents of the barrel should be thoroughly stirred with a long wooden paddle to insure a uniform consistency. If the slip is found to be still thin another settling and removal of the water will thicken it.

The slip thus prepared will keep indefinitely, provided that it is not allowed to become dry by evaporation. It improves greatly with age. This is the material which is used for casting as will be described later but for plastic work it must be still further thickened. A shallow box may be procured and made water-tight and the slip, when poured into it, will thicken much more rapidly than in the barrel, but it is better to have some shallow plaster dishes as the plaster itself absorbs the water and thickens the clay. Instructions for making these dishes appear in the chapter on plaster.

These directions will suffice for the preparation of a natural clay but it is sometimes desired to prepare a white body either of earthenware or porcelain. These bodies do not exist in nature and therefore a mixture must be made. The ingredients are kaolin or white porcelain clay, ball clay or plastic potters' clay, ground quartz or flint, and ground feldspar.[B]

A suitable mixture for earthenware is—

and for porcelain—

The earthenware will be creamy in color and porous at an ordinary fire. The porcelain will need a hard fire and will be white and translucent. It is, however, non-plastic and hard to work. The preparation of these mixtures of course necessitates a pair of scales but otherwise the treatment of the mix is the same as that of natural clay. Washing is not necessary but the clay must be powdered, mixed with the flint and spar, and sprinkled into water as already described. In place of the wire sieve, however, a silk lawn of 120 meshes to the inch should be used.

The lawn is simply a fine sieve and is named because of the material (also called bolting cloth), with which it is covered. Have a carpenter make a box without a bottom. Cypress or oak should be used and this should be a full half inch thick. Four strips of the same thickness are also to be provided. The box may be of any convenient size; eight inches square and four inches deep is about right. The sides should be fastened together with brass screws to avoid rust and a piece of lawn is strained tightly across the bottom and secured with copper or brass tacks. A strip of coarse muslin folded and laid along the edges will help to prevent the lawn from tearing, the tacks being, of course, driven through both muslin and lawn. Then the four wooden strips are set upon the muslin and secured with brass screws. The completed lawn is then a tray of which the bottom is formed of lawn. The strips of wood beneath serve to protect the lawn when placed on a table as well as to assist in holding it firmly.[D]

For storing clay in the plastic state there is nothing better than stoneware jars. These may be had of any size and a tinman should make close-fitting covers. Earthenware covers do not fit tight and are always getting broken. A little water is poured into each jar and a support provided for the clay so that it does not rest in contact with the water. Under any conditions clay will slowly harden so that not too large a stock should be kept. Slip, on the other hand, keeps well so long as some water is always on the top and it is not a long process to stiffen it into clay.

CHAPTER VI
Mold-making and Plaster

Plaster is almost a necessity to the potter and therefore something should be learned about it. Even if one does not use molds there are numberless purposes for which plaster is convenient. For stiffening slip into clay, and for absorbing water from glazes, shallow dishes of plaster are used, and for holding work either in making or drying, plaster bats or round slabs are always in demand.

It is best to purchase the finest quality of potters' plaster by the barrel.[E] It will keep indefinitely if stored in a dry place. The necessary appliances are:

• One or two large jugs for mixing, or a metal can with a spout.
• A metal spider or frying pan.
• Six feet of rubber machine belting, six inches wide, or similar strips cut from linoleum or enameled cloth.
• Two or three thin pieces of steel of various degrees of flexibility (scrapers).
• Handy knives, called vegetable knives.
• A small painter's brush.
• Two or three fine sponges.

To begin with, a size of soft soap and water is prepared. Put a quart of water into a kettle and add a piece of soap the size of an egg.[F] Simmer for an hour or until the soap is entirely dissolved and then set aside to cool. When cold the size should be of the consistency of maple syrup. This size is used whenever plaster is to be kept from sticking to a form or surface, and it has also the merit of causing clay to stick to plaster. For example, if a mold is to be taken from a clay model no size should be used, but if a plaster form is used as a foundation for clay ornament it should be well sized first. The size is laid on with a brush and wiped off with a sponge. Another sponge is then used with clean water and the sized surface is washed, all superfluous water being removed. Size is then applied a second time and washed off as before. A third application is sometimes necessary, or until the sized surface rejects water like grease does. On the last sizing, water is not applied, but the surface is polished with the sponge containing size. If the surface to be prepared be of wood or metal a single coat of size will often suffice, but if it be of plaster three or four applications are often necessary.

The first lesson may well be the manufacture of a plaster bat. The frying pan is first sized and set upon a level table. Let us suppose that a quart of water will fill it to about an inch in depth. This amount of water is put into a jug and two pounds and three-quarters of dry plaster is weighed out and allowed to trickle through the fingers into the water. This proportion has been found to be best for ordinary mixings. A smaller quantity of plaster to the quart of water will result in a very soft bat; a larger quantity will be proportionately harder. After the plaster has soaked up all the water it will take, that is in about two minutes' time, the hand is plunged in and the whole stirred to a smooth cream. All lumps must be broken up and the air bubbles removed as far as possible. Continue stirring gently and presently the mixture will be felt to grow thicker. The psychological moment arrives when the plaster forms upon the hand a white coating which cannot be shaken off. The creamy liquid is then poured into the frying pan which is gently shaken to level the surface.

If the plaster has been poured at the right moment it will set smoothly with a mat surface like sugar icing. If poured too late it will be stiff and difficult to level, and if poured too soon it will curdle on the surface and water will be seen above the plaster. A little practice will show the right moment. The jug should be washed out immediately while the plaster is soft. In the place used for plaster work a tub should be provided in which all vessels and tools can be washed, for, if allowed to flow down the waste pipe of a sink, the plaster will speedily choke the outflow.

After standing for some ten minutes, more or less, the bat in the frying pan will grow warm. This is the sign of a combination between the plaster and the water and shows the completion of the setting. The pan is now taken by the handle and, holding it upside down, the edge is rapped smartly on a brick or stone. This will cause the contents to fall out and there is a smooth disc which is one of the most useful of appliances. The edge will need to be scraped and the bat can be set aside until needed. It will be good practice to make a half dozen of these.

This process of mixing and pouring plaster is the same for all operations and the instructions will not be repeated, but when the student is told to "pour plaster" it will be presumed that this experiment has already been made.

Fig. 1. A, table. B, clay mound. C, plaster. D, rubber belt.

The next step is the making of a plaster bowl or dish for the purpose of drying out slip or glaze. A convenient size should be determined upon as it is best to have all the dishes the same. Upon any flat, smooth surface a mound of clay is reared which shall be the size and depth of the inside of the proposed dish. About twelve inches in diameter and three inches deep is a good size, though fourteen inches is not too large for the former dimension. This mound should be made as nearly circular as possible and the clay finished as smoothly as may be. The rubber belt is then set around the mound in the form of a hoop leaving a space of two inches between the clay mound and the rubber hoop. The rubber is fastened either by tying with string or by binding the overlapping ends with clothes pins. A roll of soft clay is laid down where the belt joins the table and pressed down outside to prevent leakage. Enough plaster to fill the space within the belt is now mixed and poured, covering the clay mound to a depth of at least one inch. When the plaster has set the rubber is detached, the whole turned over and the clay dug out. We have now a circular plaster dish three inches deep but we have only one. The trouble of rebuilding the clay is unnecessary a second time because a "case" or reverse can be made from which as many dishes as may be necessary can be formed.

Fig. 2. C, plaster dish. D, rubber belt. E, plaster case or reverse.

Fig. 3. Plaster case, with rubber belt, arranged for pouring.

The dish is carefully smoothed and trimmed. The sharp edge is removed and the inside is dressed with fine sandpaper to a perfectly smooth surface. Size is now applied to the inside and upper edge until a bright slippery surface is obtained. The rubber belt is now bound closely around the dish and plaster is poured to a depth of about one and one-half inches on the edge. This, of course, makes a depth of four and one-half inches in the center. When this new plaster has set in turn the rubber is removed and the two castings can be easily separated by inserting a knife at the junction. The knife should be gently driven in with a hammer. Obviously it is now possible to make a number of dishes from the reverse thus obtained, by simply binding the rubber belt around each time and pouring plaster as at first. The original mold having been sized is no longer absorbent but must be kept in case additional reverses are needed. The molds or dishes must be thoroughly dried out before being used.

The molding of a vase form is more elaborate but not really difficult. Even if one does not intend to produce pottery by molding there is always an advantage in having a number of simple forms upon which to make experiments.

The vase to be molded is first drawn to exact size upon paper and a plaster model is turned on a lathe. This can be done equally well on the potters' wheel and the method is as follows: A plaster bat is saturated with water and set upon the wheel so as to run true when the wheel is revolved, and is cemented to the wheel head by a little slip. A few deep scratches are made on the face of the bat and a cylinder, either of the rubber belt or of stiff paper, is rolled up and set on end in the center of the bat. The size of the cylinder should be a little larger every way than the proposed vase. Plaster is now mixed and poured to fill the cylinder. It will adhere to the bat below by reason of the scratches. When the plaster has set, the cylinder is unfastened and removed and the turning may begin. To turn plaster well involves a good deal of practice but it is better to spoil three or four plaster cores in the learning than to spend a long time on one for fear of damaging it.

Fig. 4. Turning tools for plaster.

Fig. 5. Position of tool in turning. A, correct. B and C, incorrect.

The board support and turning stick described on page 100 are used in turning plaster as well as clay. The turning stick is held in the left hand and the point is pressed into the board. All this is, of course, made ready before the plaster is poured. The turning tools are here illustrated. They are not sold in the stores but can be made by any machinist. The head or cutting blade consists of a flat piece of steel through the center of which is a shaft or pin which is driven into a handle. The head may be of any shape but the triangle and the circle will meet every need. The tool is held in right hand and braced against the turning stick, the stick and tool being moved together by raising or lowering the left hand which holds the butt of the stick.

While the plaster is still soft the round tool is used and the rough form is rapidly turned. Then as the setting of the plaster proceeds and it is found to grow harder, the triangle tool should be used and the shape gradually wrought out with the point. Finally by using the circle tool for concave lines and an edge of the triangle tool for convex lines the form is perfected. The surface is to be finished and the tool marks removed by using, free hand, a flexible scraper which is bent by the fingers and thumb to fit the lines of the form, and a final smoothing is given by fine sandpaper, the wheel being revolved all the time. At the top of the form a small cylindrical piece is left, called the "spare" which represents the thickness of the mold substance, and for the bottom a small piece is turned in the shape of a truncated cone. The small end of this should be the same diameter as the base of the vase. These are shown in the illustration (Fig. 6).

Fig. 6. Vase with foot piece and template. A, vase. B, spare. C, foot piece. D D, templates. N N N N, natches.

It will be obvious that in the directions given above the base of the vase is not finished off and therefore the form must be cut off from the bat, either by a knife or saw, and the base is then finished by hand, or by setting the form upside down in a clay cradle—called a "chum"—and turning the base true. The form is now ready for molding.

Fig. 7. End plates for mold. E, upper plate. E', lower plate. N N, natches.

The plaster vase is laid upon its side on a piece of soft clay and a thin bat or plaster slab is cut to fit the outline. This template should fit with reasonable accuracy but need not be absolutely exact. A pair of these will be required, one to fit each side of the form. These slabs or sheets of plaster are always useful and if a sheet of glass is kept handy any excess of plaster left from a mixing may be poured on to it. This upon setting is easily detached and will present a smooth face where it has rested on the glass. The pair of templates must include, in their outline, both the spare and the foot piece but should not extend beyond either of these. The outside diameter of the mold is now to be determined and the templates cut to this dimension so that the two together, with the vase between them, constitute a longitudinal section of the mold.

The vase must now be divided accurately into two halves by a line running from top to bottom. There are several ways of doing this. While the form is still on the bat a diameter of the bat may be drawn and a perpendicular erected from each end of this diameter. These perpendicular lines will, of course, mark the center of the vase on each side; or after the vase has been cut off another method is possible. With a pair of dividers find the center of both the top and the bottom of the vase. Mark each with a small hole or the point of a pencil. Now lay the vase on its side on the clay cradle upon a glass sheet or other level surface and raise or depress one end until the two centers are exactly the same height from the glass. Take this height in the dividers and, sliding one of the compass legs along the glass, gently scratch the plaster vase with the other or upper point. If the two centers have been accurately adjusted this scratch line will be the exact center of the form.

Some soft clay is now built up on each side of the vase and the templates are pressed down upon it, one on each side until the upper face of each corresponds with the scratched line. The vase is now seen to be buried as to one half in a plaster surface, and plaster poured on this will give a half mold. There is yet, however, nothing to confine the plaster and it would flow away as fast as poured. Two end plates are necessary and these must rise in a half circle above the bed formed by the templates. The part below may be of any shape but must be high enough to cause the diameter of the half circle to coincide with the plane of the templates. Two pieces of cardboard, wood, or rubber belt are now bound to the sides, the apertures at the top and bottom, caused by the curve of the end plates, are stopped with clay and the whole presents the appearance of a vase, only half of which is visible, lying in a shallow trough. All the fitting should be carefully done but the tying up is not yet. The whole is now taken apart and well sized. Vase, foot piece, templates and end pieces are all to be sized thoroughly in the manner described. They are then put together again and bound around with twine. It is necessary now to make provision for the proper fitting of the halves of the mold. This is done by providing knobs and hollows which fit together. These are technically known as "natches" and will be referred to as such. Take two pieces of moderately stiff clay each about the size of a cherry. Roll them into neat balls and cut them in two with a thin knife. Lay each of the halves, flat side down, upon the templates, two on each, placing them in pairs opposite to each other. Affix two or more of these on the inner face of the bottom end plate. Now mix and pour the plaster. This should be poured to the height of the top of the end plates and, after pouring, shake this well down by dipping the fingers into it, so that no bubbles may cling to the surfaces below. As soon as the plaster has become firm but while it is still soft remove the string and the side boards, pull off the pieces of clay and with a straight, thin piece of wood scrape off the surplus of plaster by following the line of the end plates and thus making a half cylinder.

As soon as the plaster has become warm the whole may be turned over and the templates and end plates removed. The four half spheres of clay will be found embedded in the face of the plaster and these, being removed, will leave four hemispherical depressions. The vase can now be gently detached from its bed and the first half of the mold is completed. A little dressing will be necessary. All overhanging edges and rough places should be finished off and the hollow natches smoothed with a piece of muslin on the end of a finger.

The second half is simple. Replace the vase in the half mold, set the foot piece in its place, replace the end plates with the diameter on the line as before but with the semi-circular edges upward, and set two or three clay natches on the bottom one. Size, bind up, pour and scrape off as before, thus completing the two halves of the mold in cylindrical form. It only now remains to make the bottom for, at present, the mold is open at both ends.

The two halves with the vase inside are bound very tightly together with twine and set on the table bottom upwards. The clay natches in the bottom are taken out and the hollows smoothed. The foot piece is taken out and the rough places dressed. The bottom end of the vase is now visible and this, together with the end of the mold, is sized. A strip of stout paper is bound around the mold, projecting about an inch above the end and plaster is poured to fill it. When this is set the paper is peeled off and the edges of the mold are dressed smooth. The bottom may now be detached by inserting a thin knife at the junction, the mold opened and the form taken out. The mold is now in three parts which may be put together at will and used for casting the vase in clay.

CHAPTER VII
Cases and Working Molds

The mold described in the previous chapter is called, technically, a "block mold" and is not, as a rule, used for making the clay ware. The reason for this is that molds will wear out more or less rapidly and to repeat the process of making new ones from the original form would be tedious and expensive.

From the block mold a reverse is made, called a "case," and from this, in turn, working molds are made in any required number. While it is possible to use the block mold as a working mold, and, if only a few pieces are required this is quite sufficient, yet, as it is often necessary to have a number of molds, the student should understand how to make a case.

A case may be defined as a mold from which a mold is made. If one can imagine the visible half of the vase form as it appears in making the mold, with the templates and ends cemented into one piece, one has a conception of one half of a case. The problem is to make this with permanent but movable ends so as to have a convenient form from which half molds may be easily made.

Fig. 8. Offset plates. F, top plate, front view. F', side view. G G', bottom plate.

Fig. 9. Sectional view of mold ready for casing. A, mold. B B, offset plates. C C, end plates. N N, natches.

The ends are joined to the body by means of offsets and the first step is the construction of these. One half of the block is taken and laid upon its back, being supported by clay so that the face is level and steady. An offset plate is now cut to fit each end. To make these a piece of plaster is selected or made which is true and smooth on both sides. The plates are cut of the same width as the mold and are beveled at the upper edge so as to rise slightly from the mold face. The curve at the end of the mold is cut out to fit and beveled in like manner. Then two end plates are fitted. These should be about two inches higher than the offset plates and are square at the top. Upon each of these two or three clay natches are set, being placed low down near the face of the mold. The mold and plates are well sized and bound together with side walls just as in the making of the mold. Plaster is poured to a height sufficient to well cover the natches and left to set hard. No shaping is necessary. When well set the end plates and offset plates are removed but the vase mold and the case are left attached together. The other half of the mold is prepared and run in the same way, the same offset plates and end plates being used with such slight refitting as may be necessary. The work is now examined and all rough places and scraps of adhering plaster are removed. The two halves of the case, the half molds being still attached, are set up on end, back to back, being separated by a thin piece of plaster or a strip of cardboard which should extend two inches above the top. The top ends are now sized, the natch holes having been smoothed off, a band of paper is tied around and plaster poured on top to a depth of about one inch. When set the whole is turned over and the operation is repeated on the other end. After the final setting the ends are easily removed and by the insertion of a thin knife driven by a light blow, the molds and case are separated. Each half case is now laid on its back and the proper ends are fitted in place. It only now needs the usual side walls to be tied on and molds can be made with ease just as the original block mold was made.

Fig. 10. Mold and case in position. The top ends are lifted to show fitting. The bottom ends are not shown.

It now remains to make a case of the bottom mold. The bottom piece of the block mold is taken and sized and with a strip of paper bound around it, plaster is poured. The two are detached when set and the case is finished. It consists of seven pieces; three are used in each half and one for the bottom.

Thus equipped it is possible to make any number of working molds and if the case should wear out or be damaged, a new one can always be made from the block mold. The block mold itself, having been sized, is no longer absorbent and cannot be used for making vases. The working molds should be thoroughly dried before using and they will last longer.

Flat ware, such as plates and saucers, is made on, not in, a mold. The diameter of the plate having been decided upon, a block of plaster three inches wider is run. This is placed on the center of the wheel or jigger and in it the face of the plate is turned. This must be sunk below the level of the block and when finished, must appear as though the plate itself were embedded in the plaster. One half of the thickness of the edge is shown in such a way that there is no under cutting. Just outside of this edge the plaster is turned so as to slope gently up to the level of the block.

Fig. 11. Block of plaster with face of plate turned. B, height of plaster to be poured. C, rubber belt.

Without removing the block from the wheel the face of the plate is well sized, a band of belting is arranged, of the same diameter as the edge of the slope and plaster is poured to a depth of three inches. Out of this the back of the mold is turned as shown in the illustration (Fig. 12).

Fig. 12. A, block of plaster. B, mold poured on face of plate and turned.

The top of this as it lies upside down is shaped with a straight, almost upright slope which enables the mold to be set securely in the wheel head. Around the exposed edge of the original block, three or four natches are now bored or cut. They should be placed at irregular distances so that there will be no doubt as to the putting together of the sides of the case. If two circular pieces of plaster have to be set together and held by natches there should always be either this irregular spacing or some distinctive mark, because if this be not provided for, two or three trials will always be made before the correct fitting is found and these trials wear out the natches very quickly.

Fig. 13. A, bottom of case. B, Cavity for pouring molds. C, top of case.

The back of the plate mold and the edges of the block are now sized and plaster is run to the level of the highest part of the mold but no higher (Fig. 13). When this is set, the two halves of the case can be separated and the mold taken out. Now when the halves of the case are fitted together there will be a cavity the exact size of the mold. This can be filled again and again with plaster, a new mold being formed each time.

Fig. 14. Iron prong to fit wheel head.

Fig. 15. A, plaster, with prong inserted. B, rubber belt.

In order to use these molds a special head must be provided for the wheel. The regular head of the wheel should be detachable and in its place an iron frame called a prong is fitted. This consists of a collar either with a hollow cone or a screw to fit the shaft of the wheel, and from this radiate four short arms. In order to use this a circular block of plaster some two or three inches thick is poured on a table or slab and just as this is setting, the prong, upside down, is pressed into it just below the surface and held there until the plaster is hard enough to support the weight of the iron. When hard, the whole is lifted and the prong with the plaster attached is set in position on the wheel. This now forms a rough plaster head and it must be turned true. In this head a circular depression is to be turned which will exactly fit the back of the plate molds. If the recess should wear larger as it will if much used, a new head can easily be run. The same principle can be applied to the making of molds for saucers.

Fig. 16. Wheel head with plate mold. The tool used is shown in dotted outline.

Cups and bowls are molded from the outside. A block of plaster about one inch thicker than the height of the proposed cup is taken and centered upon the wheel. Out of this the piece is to be turned, upside down, leaving a ledge or platform, the outside diameter of which is the size of the mold. The rubber belt is tied around this and the mold poured. If for casting this will suffice, but if it is intended to make the cups upon the wheel the outside of the mold must be turned to fit a wheel-head which is hollowed to receive it. The making of the cups is described in Chapter XI. A bowl is simply an enlarged cup.

CHAPTER VIII
Building by Hand

The production of pottery by hand is a form of modeling but with the important difference that while pieces modeled by art-school methods are not intended to be preserved in the clay itself, built pieces are destined for the fire. It is therefore necessary not only that a special clay be used but that the work be such as will hold under the strain of the burn. The composition of the clay has been dealt with in another chapter and it is presumed that the worker has decided upon the proper mix or has procured a suitable clay.

There are two possible treatments of built pottery; the work may be finished by fingers and tools only or it may be placed upon the wheel and turned to a true surface. In the latter case the result is much the same as if the piece were thrown on the wheel as will be described. The principal point of difference is that while building needs less practice than throwing, turning a built piece is much more difficult and tedious than turning a thrown one. It is almost impossible to build with sufficient accuracy for the work to run true, and a great deal of time is consumed in filling hollows and removing lumps. These do not appear obtrusive when the work is held in the hand, but if it be revolved upon a fixed center every slight irregularity appears to be accentuated. On the other hand the charm of built ware lies in the subtle plastic quality which belongs to no other material or method.

For very large pieces such as tree pots the combination method is useful but these should be built on the wheel itself and kept true as the work proceeds. Then a slight turning at the finish, when the clay is leather hard, will produce a satisfactory result.

The clay for building should be rather soft as it is apt to dry quickly on handling. The work may be done either with coils or pieces.

A plaster bat should be made with a low dome in the center. This bat may either fit the wheel or not, depending upon the plan adopted. The dome is to raise up the bottom of the vase and form a foot. The table may be covered with a piece of oil cloth or may be kept slightly damp. The first attempt should be to build a cylinder as this form is easy to construct and to keep true, so that the attention may be devoted to the manipulation of the clay.

It is first necessary to roll out the clay into cords which should be a little thicker than the proposed walls are to be. These cords should be as uniform as possible and should be rolled quickly to avoid undue hardening. It is best to roll them as required. The domed bat is made quite damp and upon it should be marked the diameter of the cylinder to be built. A roll of clay is taken, one end laid in the center of the bat and the rest is coiled around it in a spiral line. When the disc so formed has reached the proper size, the coils are gently rubbed over with the fingers until they have thoroughly united and the lines of the spiral have disappeared. The clay disc may now be turned over and the rubbing continued on the other side. The circle is cut true and a new coil is laid on the outer edge thus making a shallow circular tray. In raising the walls it is best to pinch off the roll of clay when one circle has been completed and the new roll should be begun at another point so that all the joints will not be at the same place. This plan is better than coiling a long roll in a spiral for in this case one side of the piece will be higher than the other.

After three rolls have been laid in position the wall, both inside and out, should be worked like the bottom so that the rolls will disappear and the clay be welded uniformly together. This should be done without water or with as little as possible. The use of water is very tempting. It makes the clay so smooth and seems to help but it will inevitably make the work sloppy and will tend to soften the walls.

After three or four rolls have been worked in, the piece should be laid aside for some hours to stiffen. If this be not done the weight of the second building will cause the work to sag and fall out of shape. For this reason it is well to have two or three pieces in hand at once so that there need be no waiting. When the cylinder is of sufficient height it should be allowed to become quite stiff and then the irregularities should be corrected with a little soft clay which is worked into the joints. The whole surface may now be gone over with tools and brought to the required finish. As soon as the clay is hard enough it should be removed from the damp bat and placed upon a dry one to become dry.

In the method of building by pieces no rolls are prepared but the clay is taken, pinch by pinch, each morsel being pressed into place as the work goes on. This plan is somewhat more plastic in effect and is well adapted to free-hand work; the resulting pottery, however, is generally thicker and heavier.

The craft of building is not mastered until the lines of a drawing can be successfully followed. The clay is apt to choose its own way and the result will be very different from what the potter intended. The design should be carefully worked out on paper, full size if possible, and the clay form should be compared with the drawing as the building goes on. A profile may be cut in cardboard and this, applied to the clay from time to time, will verify the line, but all such mechanical aids should be used sparingly as the value of this work depends largely upon the sense of freedom and self-expression which belongs to it.

The thickness of the clay walls is a matter of great importance. A small piece should not be so thick as to feel clumsy and heavy, nor should a large piece be so thin as to lose the sense of strength and solidity.

It may be found on drying the ware, that cracks, especially in the bottom, are developed. The cause of this may be in the clay. A clay which is too plastic or too fine in the grain will surely crack. Such a clay may be opened or meagered by the addition of ground flint or fine grog. The cause may, on the other hand, be in the building. If the welding of the coils or pieces be imperfectly done, cracks are sure to result. If the bottom be too thick it will crack. A great strain is put upon the bottom in drying. The clay must be able to shrink and while the side walls are able to settle down on themselves, the bottom is pulled in every direction by the sides. The bottom should be made quite thin in the center and thicker toward the edges. This will help to avoid cracks. A bad crack cannot be successfully mended. It is best to break the piece and begin again. To burn it means the loss of the clay but the clay will be saved if the damaged work be withheld from the kiln. A small crack on the edge is also hopeless. A crack showing on the edge of a piece is a bad fault. A small crack in the bottom may be mended by dampening the place carefully and pressing in a little stiff clay.

CHAPTER IX
The Potter's Wheel

Much of the glamour of the potter's art is associated with the wheel. Poets have sung its praise and artists have delighted in its rhythmic motion, but alas! the wheel as a commercial method of manufacture is doomed to extinction. It cannot compete with the precision and speed of machinery. It devolves, therefore, upon the artist potter to maintain the wheel in its rightful place as, par excellence, the potter's tool.

No clay worker's studio should be without a wheel, but the particular form of wheel depends upon the nature of the circumstances under which it is to be employed.

The simplest wheel is that used by the Chinese. A circular plate with a heavy rim is set upon a spindle so that it will revolve freely and run steadily. As the workman sits or kneels upon the floor the surface of the wheel is about at the floor level. Around the periphery and upon the upper surface four holes are sunk and the workman, inserting a short stick into one of these, gives the wheel a rapid motion. Then while it is revolving by its own momentum the clay is centered and shaped. As the motion is lost the stick is again inserted and the wheel spun. This method, of course, involves much skill on the part of the workman.

In the next form, one which is only adapted, however, for crude experimental work, the wheel is set upon the frame of a sewing machine and operated by the treadle. A beginning may be made upon such a wheel but the operator will soon wish for something better.

A common factory form and one which is well adapted for studio work is the kick wheel. The wheel head is set at the top of a spindle and in the upright shaft there is a crank to which is attached a horizontal moving treadle. This is worked continuously by the left foot, the weight of the body being supported by the right. The action is strenuous and scarcely fitted for persons of other than robust physique but it can be used successfully after practice. This wheel is made by the manufacturers of potter's machinery.

Another form of the kick wheel is used in Europe and is, in fact, the original wheel used by the French and German potters in the seventeenth century. The head is set on a spindle as usual but instead of the crank there is a large heavy disc on the bottom of the shaft and revolving in a horizontal plane. This is within reach of the foot and the operator, being seated, imparts a rapid motion by pushing, usually with the ball of the right toe. The momentum is kept up by the weight of the disc and there is a great advantage in that the foot need not be in continuous motion. On the other hand it is difficult to acquire sufficient speed and power for the work.

There are several forms of machine wheels which are entirely satisfactory but which need the application of power. If a gas engine or a water motor or electric current be available, every effort should be made to obtain a wheel of this description. The prime motion is imparted to a short horizontal shaft which moves at a constant speed. Then the operator, seated in comfort, regulates the speed of the wheel itself by pressure upon a treadle. No action is required but a simple pressure, light for a slow speed and heavy for rapidity. Where the electric current is available, nothing could be better. Self-contained motor-driven wheels are available but are rather expensive.

One more plan may be mentioned in which the wheel is simply a vertical lathe with a belt and handle to be turned by an assistant. This may be convenient for some but it is not always possible to secure help at the moment when the wheel is to be used. Moreover the cost of labor would soon pay for a mechanical wheel.[G]

Whatever type of wheel is selected it should be arranged with a head which can be removed. There are two methods of constructing this; the head may be screwed on to the spindle, or the latter may terminate in a cone-shaped plug upon which the wheel head is made to fit as in the illustration (Fig. 14). The latter plan is to be preferred as the head can be removed more quickly and is not so likely to work loose. Several heads for the wheel can then be provided, one for regular work, one for making plates, one for finishing and so forth.

The regular operation performed upon the wheel is termed either throwing or turning according to the industry in which it is employed, but in this description the word "throwing" will be used because the subsequent operation in which tools are employed is best described as turning.

The best head for the wheel to be used in throwing is made of hard wood or brass because the ball of clay can be easily centered upon a smooth surface. This, however, involves that the work shall be cut off with a wire and removed while soft. This is commonly done by professionals but is beyond the skill of the beginner. It is best, therefore, to use a head like that illustrated for plate making and to have a number of specially shaped plaster bats to fit the recess (Fig. 17). Then when the piece is formed, the bat with its burden can be set aside for the work to harden.

Fig. 17. Wheel head with detached bat.

Throwing is not an easy operation to describe but the following instructions in the form of lessons will, with a large amount of practice, enable the student to become fairly expert. Every opportunity should be taken to watch a good potter at work. There are a thousand and one little tricks in the position of the arms, hands, thumbs and fingers which are impossible to describe but which can easily be copied. If a kick wheel be used some time must be given to practicing the motion without using clay. The action of the foot must become subconscious or automatic like the pedaling of a bicycle so that simply to will a change of speed is to accomplish it.

Fig. 18. The progress of a clay ball on the wheel.

Lesson I. Take the bat about to be used, plunge it in clean water and soak it nearly, but not quite, to saturation. If the bat remain wet one minute after being taken from the water, it has soaked too long and must be dried off a little. The effect of a wet bat is that the clay slips and cannot be held in one place. The proper dampness is secured when the clay ball can be pushed along the surface of the bat but does not slip easily. This condition is important and should be secured by experiment, because if not right, good work will be impossible.

PLATE I. Throwing.—Lesson II, 1.

PLATE II. Throwing.—Lesson II, 2.

Lesson II. Place a small basin of water close at hand. Take a ball of clay about three inches in diameter. Set it on the center of the wheel as nearly as can be judged. Now spin the wheel at a fairly rapid rate. Brace the left elbow against the side and, wetting the hand, press the ball of the thumb and the lower part of the palm against the clay. The left forearm being kept rigid, the clay as it revolves will be forced into the center of the wheel. Use the right hand to sprinkle water on the clay that proper lubrication may be maintained. With the fingers of the right hand pull the clay towards you, at the same time pressing inward with left hand and so squeezing the clay. As the hands come together the clay will rise in a cone. Do not pull it upwards but let it rise as it is squeezed. Now bring the hands over the top and with the thumbs together press down again. Lumps and irregularities will be felt in the clay and the operations of spinning up and pressing down must be continued until these disappear. Repeat the exercise of centering with a fresh ball of clay until it can be accomplished with ease and rapidity. The clay so used is not wasted. The superfluous water may be dried off upon a plaster bat and the clay wedged up for use again.

PLATE III. Throwing.—Lesson II, 3.

This wedging or waging of clay—the word has descended from the old English potters—is important. A strong table should be built of which the top, measuring about 30 by 20 inches, is made of two-inch plank. A raised edge two inches high is fastened firmly by being nailed to the sides; the trough thus formed is then filled with plaster and allowed to harden. An upright post is fastened in the center of one side and from the top of this a fine brass wire is stretched to the other side of the table, thus making a diagonal. The worker stands at the side of the table opposite the post. The ball of clay is taken in both hands and cut in two against the wire, then the pieces are slapped smartly upon the plaster, one on top of the other. The whole lump is then lifted, cut in two and slapped down as before. The lump of clay is thus formed into layers, the irregularities in hardness are corrected and the clay made smooth. A little practice will make the work quite easy but it will often be found necessary to cut and beat the clay fifteen or twenty times before a good texture is secured. If the plaster table be dry the clay will be stiffened rapidly but the plaster may be made wet to prevent this if it should not be necessary. A clay may also be softened in this way by sprinkling it with water as the wedging goes on.

PLATE IV. Throwing.—Lesson III, 1.

PLATE V. Throwing.—Lesson III, 2.

Lesson III. Center the ball as in Lesson II and moisten both hands and the clay. Grasping the clay lightly but with sufficient force, press the right thumb downwards and towards the palm and a cup-shaped hollow is formed in the clay. Raise the right hand slowly, still keeping a light pressure upon the clay with the thumb. The clay wall will rise with the hand. Now insert the two first fingers of the left hand into the hollow and hold them against the right-hand wall. Slacken the speed of the wheel a little. Bend the forefinger of the right hand and press the second joint and the knuckle against the outer wall so as to oppose the fingers which are inside. Press the thumbs together to steady the hands and raise both hands upwards together. The fingers inside and outside the clay should be kept at a definite distance apart so that as the hands rise, the clay is brought to a uniform thickness. The hands are brought steadily to the full height to which the clay will go and thus a cylinder is formed.

Repeat this lesson three or four times with fresh clay.

PLATE VI. Throwing.—Lesson IV, 1.

PLATE VII. Throwing.—Lesson IV, 2.

Lesson IV. Keep the hands wet. Shape the clay cylinder as directed in the previous exercise. Now repeat the action of the fingers inside and outside and, beginning at the bottom, take a closer grip of the clay and draw up the walls as before. The cylinder is now taller and the walls thinner. Do this again and again taking a little closer grip each time until the cylinder is as tall and as thin as the clay will bear. The walls will probably spread as the work proceeds and the hands must then be used outside. Grasp the clay with both hands and squeeze it slightly; at the same time raise the hands upwards. This will reduce the diameter of the cylinder and thicken the walls. The operation of the fingers can then be repeated until the full height is reached. There is, of course, a limit to the height of the cylinder which can be made from a given lump of clay and it is best to begin on a small scale. A ball of clay which can be easily grasped with the hands is the proper size with which to learn. A very small ball is nearly as hard to work as a large one. Repeat this lesson until a tall cylinder can be made with ease and certainty.

PLATE VIII. Throwing.—Lesson V.

Lesson V. Keep the hands wet. Spin up a cylinder with thick walls as in Lesson III. With the fingers of the one hand inside and those of the other hand outside, open the cylinder gradually. Keep the wheel at a slow speed. If the edge runs unevenly, use both hands outside to steady it, then work outwards again until a shallow bowl is formed.

PLATE IX. Throwing.—Lesson VI, 1.

Lesson VI. Keep the hands wet. Spin up a cylinder of medium height as in Lesson IV. With the fingers of the right hand outside press inwards at the base of the cylinder close to the bat and with the fingers of the left hand inside, press outwards at a slightly higher level. This will reduce the diameter at the bottom and increase it in the middle, making a cup shape. Now raise the right hand and gently draw the top inwards. With the left hand inside press the upper edge outward and with the fingers of the right hand shape the upper part into the form of a jar or flower pot.