SOMETHING ABOUT SUGAR

Refined Sugar Showing Form of Crystals

SOMETHING ABOUT SUGAR

ITS HISTORY
GROWTH, MANUFACTURE AND
DISTRIBUTION

BY
GEORGE M. ROLPH

Sugar
is nothing more nor less
than concentrated
sunshine

SAN FRANCISCO
JOHN J. NEWBEGIN
PUBLISHER
1917

COPYRIGHT, 1917, BY GEORGE M. ROLPH

PRINTED BY TAYLOR & TAYLOR, SAN FRANCISCO

DEDICATION:
TO R. P. RITHET

FOREWORD

The purpose of this book is to tell in simple language “Something About Sugar.” It gives a brief history of the commodity and its production in different parts of the world, and seeks to show, for the information, especially, of the layman and the pupil in school, the various steps by which sugar from cane and beets is prepared for the consumer.

G. M. R.

CONTENTS

PAGE
[Part I]
Growth, Manufacture and Distribution
What Sugar Is [3]
The Growing of Sugar Cane [6]
Soil Analysis [8]
Entomology [8]
Pathology [9]
The Manufacture of Raw Sugar [22]
Extraction [22]
Purification [25]
Evaporation [28]
Concentration and Crystallization [31]
Preparation of Crystals for the Market [33]
Transportation and Delivery of Raw Sugar [37]
Polarization [39]
Refining of Raw Sugar [44]
Washing [50]
Melting [54]
Defecation [54]
Bone-char Filtration [59]
Crystallization [65]
Partial Drying [69]
Final Drying of Crystals [69]
Screening [71]
Packing [73]
Cube Sugar [77]
Powdered and Bar Sugar [79]
Yellow Sugars [81]
Mechanical Department [84]
Laboratory [87]
Cost of Refining [88]
Shipping Department [91]
Marketing [93]
Beet Sugar [100]
The Sugar Beet [102]
Selection of the Soil [103]
Planting [104]
Thinning [106]
Cultivation [107]
Harvesting and Topping [107]
Manufacture of Beet Sugar [110]
Transportation and Cleaning [110]
Extraction of Juice, Slicing and Diffusion [111]
Purification of Juice, Carbonation and Filtration [112]
Concentration of Juice [113]
Sulfitation [114]
Formation of Grain [115]
Steffen Process [115]
[Part II]
History of the Industry
Early History [119]
Beet Sugar in Europe [128]
Beet Sugar in the United States [148]
Territory of Hawaii [163]
Louisiana [175]
Porto Rico [182]
The Philippines [189]
Cuba [201]
Jamaica [213]
Barbados [220]
Trinidad [224]
Santo Domingo [227]
Guadeloupe and Martinique [233]
Guadeloupe [233]
Martinique [234]
Guadeloupe and Martinique [236]
Mexico [243]
Peru [249]
Brazil [256]
British Guiana [264]
Argentina [271]
Formosa [276]
Java [283]
Australia [302]
Mauritius [309]
Natal [317]
Egypt [320]
Spain [324]
India [330]
Conclusion [338]

ILLUSTRATIONS

Part I
Growth, Manufacture and Distribution
Refined Sugar, showing form of crystals [Frontispiece]
Sugar Cane, showing eyes or buds [To face page 4]
Roots of Sugar Cane [6]
Jungle-like Vegetation of Cane Field [7]
Leaf-Hopper [10]
Sugar Cane [11]
Experiment Station [12]
Plantation Scene in Hawaii—light-colored foliage is sugar cane [13]
Steam Plough [14]
Planting Cane [15]
Irrigation Ditch, showing tunnel [16]
Irrigation Ditch [17]
Young Sugar Cane [18]
Ripe Sugar Cane, showing tassels [19]
Cutting Cane [20]
Loading Cane [21]
Train-Load of Cane ready for the mill [22]
A Modern Mill [23]
Cane Carrier and Mechanical Unloader [24]
Another Type of Cane Unloader [25]
Twelve-Roller Mill [26]
Modern Crushing Plant; two fifteen-roller mills and crushers, capacity 105 tons per hour [27]
Delivering Bagasse to Fire-Room [28]
General Interior View of Modern Raw-Sugar Mill [29]
Filter Presses [30]
Set of Quadruple Evaporators [31]
Vacuum Pans [32]
Centrifugal Machines [33]
Filling, Weighing and Sewing Sacks [34]
Train-Load of Raw Sugar leaving mill [35]
Steamer Loading Sugar Alongside of Dock [38]
Loading Sugar at an Outport in Hawaii [39]
Polariscope (in body of text) [Page 40]
A Modern Refinery, showing water and rail transportation facilities [To face page 46]
Plan Elevation of a Modern Refinery [47]
Steamer Discharging Raw Sugar at Refinery Dock [48]
Sugar Stored in Warehouse—25,000 tons shown in this picture [49]
Cut-in Station, showing sugar first entering the refining process [50]
Centrifugal Machine, motor driven [51]
Bag Filters, showing bags in place [56]
Filter Presses [57]
Making New Bags and Lining the Washed Bags [58]
Printing the Empty Raw-Sugar Bags [59]
Char Filters [60]
Char Filters, showing outlet pipes [61]
Top of Char Filters, showing pipe connections [62]
Exterior View of Char Drier [63]
Interior Arrangement of Char Drier [64]
Exterior View of Char Kilns, showing oil-burning apparatus [65]
A Refinery Vacuum Pan and Pump [66]
Arrangement of Steam Coils in a Vacuum Pan [67]
Refinery Centrifugal Machines [68]
Exterior View of Sweater [69]
Front View of Sweater, showing steam coils for heating the air [70]
Interior View of Sweater [71]
Separator, closed, ready for operation [72]
Separators, one of which is open, showing three screens for separating the sugar grains [73]
Filling, Weighing and Sewing 100-pound Sacks [74]
Filling, Weighing and Sewing 25-pound Sacks [75]
Filling Barrels [76]
Method of Handling Barrels [77]
Cube Sugar Machine [78]
Carton Machine [79]
Filling, Weighing and Sewing 2-pound, 5-pound and 10-pound Bags [80]
Laboratory [86]
Oil-Burning Boiler Plant [87]
Inland-Waterway Steamer Loading Sugar at Refinery Dock [92]
Car-Float Arriving at Refinery Dock [93]
Sugar Beet[1] [100]
Another Type of Sugar Beet [101]
Ploughing with Caterpillar Engine [102]
Planting Beet Seed [103]
Thinning [104]
Cultivating [105]
Field of Ripe Beets [106]
Topping Beets [107]
Hauling Beets [108]
Delivering Beets to the Factory by Wagon [109]
Delivering Beets to the Factory by Train [110]
General Interior View of Beet-Sugar Factory, showing filter presses in foreground; pans and evaporators in rear [111]
Diffusion Battery, showing diffusion cells in circular arrangement [112]
Diffusion Battery, showing diffusion cells in straight lines [113]
Weighing, Filling and Sewing Bags in a Beet Factory [114]
Cattle Feeding on Beet Pulp [115]
The First Successful Beet-Sugar Factory in America—Alvarado, California [116]
Part II
History of the Industry
A Modern Beet-Sugar Factory [117]
Christopher Columbus [124]
Olivier de Serres [128]
Andreas Marggraf [129]
Franz Carl Achard [130]
First Beet-Sugar Factory in the World—Built at Cunern, Silesia, 1802 [131]
Napoleon I [132]
Building in Salt Lake City, Utah, in which the First Beet-Sugar Machinery Brought to the West was Installed [150]
E. H. Dyer, the Father of Beet Sugar in America [151]
Hauling Cane in the Fields, Louisiana [178]
Hauling Cane in the Fields, Louisiana [179]
Sugar Plantation Scene in Porto Rico[2] [182]
Sugar-Shipping Port, Porto Rico [183]
Ploughing Cane Field with Steam Plough, Porto Rico [184]
Unloading Sugar Cane at a Mill, Porto Rico [185]
Ploughing Field Before Planting Cane, Philippines [190]
Ploughing at La Carlota, Occidental Negros, Philippines [191]
Hauling Cane, Philippines [192]
Carabao Mill, Philippines [193]
Old-Style Sugar Mill, Philippines, showing poor crushing [194]
Tinguian Cane Crusher, Lingayen, Philippines [195]
Old Water-Driven Mill, Island of Negros, Philippines [196]
Mill Driven by Water Power, Occidental Negros, Philippines [197]
Native Sugar Factory, Pampanga Province, Philippines [198]
Interior of Camarin, Philippines [199]
Luzon Sugar Refinery, Malabon, Rizal, Philippines [200]
Loading Sugar on Lorchas, Philippines [201]
Central Factory, General View, Cuba[3] [202]
Cuban Central, General View [203]
Cane Field, Cuba [204]
Loading Cane on Ox-Carts, Cuba [205]
Train-Load of Sugar Cane, Cuba [208]
Self-Dumping Cane Car, Cuba [209]
Morelands Sugar Mill, Vere, Jamaica. Photo by H. H. Cousins [216]
The Fleet, Morelands, Vere, Jamaica. Photo by H. H. Cousins [217]
Leveling a Cane Field, Peru [250]
Leveling Ground by Steam, Peru [251]
Planting Cane, Peru [252]
Portable Branch Line of Field Railway and Cane Cutters, Peru [253]
Hauling Cane-Laden Cars with Ox-Team, Peru [254]
Train-Load of Cane En Route to the Factory, Peru [255]
Sugar Plantation between Rio de Janeiro and São Paulo, Brazil [260]
Train-Load of Cane En Route to the Ingenio La Mendieta, Argentina [270]
Unloading a Car of Cane, Tucumán, Argentina [271]
Battery of Boilers, Ingenio, La Trinidad, Tucumán, Argentina [272]
Home of Superintendent of a Sugar Plantation, Tucumán, Argentina [273]
Ingenio Nueva Baviera, Tucumán, Argentina [274]
Ingenio Nueva Baviera, Tucumán, Argentina [275]
Kohekirin Mill, Formosa [280]
Sugar Cane Affected by the Sereh, Java [296]
Seedling Canes, Java [297]
Cutting Cane, Maroochy River, South Queensland [302]
Carting Cane to Mill, Ingham District, North Queensland [303]
Isis Central Mill, Childers, South Queensland [304]
Cane Unloader, Mulgrave Central Sugar Mill, Cairns District, North Queensland [305]
Sugar Mill, Nahan Factory, India [330]
Centrifugal Worked by Hand, India [331]
Wooden Mill from Gorakhpur, India (in body of text) [Page 332]
Boiling by Old Method, India [To face page 332]
Furnace and Pans for Making Rab, India [333]
Stone Mill, Agra, India (in body of text) [Page 333]
Small Locomotive Used to Draw Cane-Cars, 2-foot Gauge, India [To face page 334]
Loading Cane Carrier, Marhourah Factory, India [335]
Water-Driven Centrifugals, Marhourah Factory, India [336]
Champaran Sugar Company, Ltd., Barrah Chakia, Champaran, India [337]

Part I
Growth, Manufacture and Distribution

WHAT SUGAR IS

Among the many varieties of sugar the most important are the sucroses and the glucoses. They form a natural group of substances, chiefly of vegetable origin. Chemically considered, all sugars are carbohydrates, that is to say, bodies composed of three elements: carbon, hydrogen and oxygen. Sucrose contains twelve atoms of carbon, twenty-two atoms of hydrogen and eleven atoms of oxygen.

Apart from sucrose, which is usually cane and beet sugar, the variety most generally met with is dextrose—one of the glucoses. It possesses less sweetness than sucrose and differs from the latter in chemical composition. As an example: dextrose is found in the raisin in small grains. It also occurs in other fruits and is the result of the inversion of sucrose.

Glucose enters largely into the manufacture of candy, being particularly necessary in the preparation of soft filling for creams, as a certain amount of it added to cane-sugar syrup prevents crystallization.

Sucrose is derived from sugar cane, maple sap, sorghum and the sugar beet. It is a solid, crystallizing in the form of monoclinic prisms, generally with hemihedral faces, which are colorless, transparent, have a sweet taste, a specific gravity of 1.6 and a melting point of about 320 degrees Fahrenheit. It is soluble in about one-half its weight in cold water, and in boiling water in almost all proportions. It is practically insoluble in alcohol, turpentine, ether, chloroform and similar fluids.

The crop of 1914-15 showed a world’s production of 18,409,016 long tons of sugar, and in the chapters relating to the history of sugar will be found a statement setting forth the amount produced by each country. The total was derived about one-half from cane and one-half from beets, produced as follows:

CANE BEET
Total in America 5,017,375 660,236
” Asia 4,268,618
” Australia and Polynesia 348,408
” Africa 523,788
” Europe 7,376 [4] 7,583,215
10,165,565 8,243,451

Sugar cane, described in botany as Saccharum officinarum, is a giant-stemmed perennial grass that grows from eight to twenty-four feet long. When ripe it produces at the top of its stalk a large feathery plume of flowers of a gray inflorescence called the “tassel,” which is from two to four feet in length.

There are many kinds of cane, all of which are regarded as varieties of one species, although some botanists have raised a few to the rank of distinct species. The cultivated types are distinguished by the color of the internodes, yellow, red, purple or striped, and by other general characteristics.

SUGAR CANE—SHOWING EYES OR BUDS

The stem of the cane is solid, with joints at intervals of three to six inches. In diameter it ranges from one to two and a half inches, and is unbranched, bearing in its upper part numerous long, narrow grass-like leaves, arranged in two rows. The leaves spring from large sheaths around the joints, and have a more or less spreading blade from three to five feet in length and two inches or more in width. The pith, of open cellular structure, contains the sugary juice. The tops, which contain but little sugar, are not crushed, but are used for seed, as the plant germinates from the eyes, or buds, which grow on the stem around the joints. Practically no cultivated cane is propagated from its seed. The roots that remain in the ground after the cane is harvested throw up fresh canes or ratoons for many seasons, after which replanting is necessary. Hawaiian growers do not count on ratoons for more than a few crops, whereas in Cuba this process can be repeated for many years.

As a rule, sugar cane consists of about eighty-eight per cent of juice and twelve per cent of fiber, the juice content varying from time to time, both as regards quality and amount. The quantity of the juice pressed from the cane determines the efficiency of the extraction, while quality is the main factor when the result of subsequent manufacture is under analysis.

It is difficult to arrive at a fair average of the composition of the juice of the cane, as it varies in different countries, on different plantations in the same country, and at different periods in any one year. The following is an approximation:

Water 80.8 per cent
Sugar 16.4
Invert sugar 1.98
Organic non-sugar .54
Ash (mineral matter) .28

THE GROWING OF SUGAR CANE

Sugar cane grows almost exclusively in the tropical belt, extending from twenty-two degrees north to twenty-two degrees south latitude, where the three essentials for its successful culture, viz., fertile soil, hot sunshine and plenty of moisture, are present. It flourishes in the islands of the Pacific ocean, particularly in the Hawaiian group, in Cuba, Mexico, Central America, the islands of the East and West Indies, Australia, China, India, along the shores of the China sea and the Indian ocean, and in certain parts of Africa and South America. In the low latitudes of the temperate zone it is grown with only fair success.

Owing to peculiar climatic conditions, sugar cane has been raised in southern Spain for generations, notwithstanding the fact that the provinces in which the sugar cane is grown lie, roughly speaking, between thirty-six degrees and thirty-eight degrees north latitude. The Gulf Stream is no doubt largely responsible for this phenomenon. The quantity of sugar produced in Spain, however, is small, the crop of 1914-15 amounting to less than 8000 tons.

Sugar cane thrives best in a moist, warm climate, with moderate intervals of dry, hot weather, and plenty of water for irrigation. It requires marly soil, free from saline ingredients. As a rule, it is raised on the lowlands, where the temperature is highest and where it is easy to bring water for irrigation. In Hawaii it takes eighteen months to ripen, and “tasseling” occurs about thirty days before it is ready to be cut. In Louisiana and Texas, because of the short seasons, cane is harvested in from nine to ten months from the time of sprouting, and, consequently, before it has attained maturity. In Cuba it is cut in twelve months, whether it is ripe or not.

ROOTS OF SUGAR CANE

JUNGLE-LIKE VEGETATION OF CANE FIELD

As the scientific culture and manufacture of sugar is probably further advanced in the Hawaiian islands than in any other part of the world, a description of the industry as carried on there will serve to illustrate the intensive cultivation and scientific methods of the present day.

The Hawaiian islands are situated in the Pacific ocean, in latitude nineteen degrees to twenty-two degrees north and in longitude one hundred and fifty-four degrees to one hundred and sixty-one degrees west, and are free from the destructive hurricanes of the East and West Indies. They are of volcanic formation and, as a rule, their centers are mountainous, in some instances reaching an elevation of nearly fourteen thousand feet. During the ages, torrential rains carried volcanic ash from the mountains toward the sea, near which it was deposited, thus forming alluvial areas of vast richness around the circumference of the islands. Parts of some of the islands are fringed with coral reefs, barriers that retain the washings from the mountains. In these low-lying areas the soil is extraordinarily fertile, and it is on such ground that the most generous crops are raised.

The soft, warm trade winds that blow from the northeast become laden with moisture as they sweep over the ocean; when they strike the cold mountain peaks the moisture condenses immediately into copious rains. The precipitation in some places reaches the astounding total of three hundred inches per annum. The rain water is conserved and, when needed, is carried to the various plantations by immense irrigation ditches.

In this tropical region there is an abundance of sunshine, accompanied by humid heat, exactly the conditions needed. It required only man’s ingenuity to utilize what nature so lavishly provided.

The commercial cultivation of sugar cane in these islands began about 1850, when a few hundred tons of raw sugar were produced, but the methods of husbandry and manufacture were crude. Time and experience worked great changes, until in 1914-15 the crop of raw sugar totaled 646,448 tons of 2000 pounds each.

For many years past the sugar planters have maintained in Honolulu an experimental station that is the marvel of the agricultural world. The bulletins issued by it are recognized as authoritative, and are read with interest in every sugar-producing country.

The most important features of the work carried on at this station are:

1. SOIL ANALYSIS

Skilled chemists examine the soils of the various plantations and, when occasion demands, advise the planter what necessary element is lacking, as well as how to obtain and apply it. A few years ago this branch of the work was considered highly important. Recently, however, the agriculturists have been depending more upon well-defined systems of experimentation. Each plantation has on its own lands plots of ground on which different methods of culture are tried and on which various kinds of fertilizer are used. Experiments are also made to determine the exact amount of water needed for irrigation. Particular attention is paid to seed cane, and a number of types of it are planted in order to obtain seed that will produce stalks that grow rapidly, yield a large tonnage per acre, contain a maximum amount of sugar, and have a high resistant power against disease and insect pests. The success attending this practical experimental work is such that soil analysis is being relegated to second place.

2. ENTOMOLOGY

A staff of trained experts assiduously study the insect life and eagerly watch for harmful, troublesome pests, which in the past have wrought great damage. It is their duty to find the means of eliminating these pests, and this they usually accomplish through the skillful use of insect parasites.

3. PATHOLOGY

The pathologists attached to the station supplement the scientific labors of the chemists and the entomologists by prescribing for any disease that may attack the cane. Plant life is subject to as many ills as the human family, and the work of these specialists in restoring health to ailing cane is of the highest importance.

To fully illustrate the character and scope of their work, a particular instance for each department may be cited:

A certain planter found that the amount of sugar obtained from his cane was decreasing yearly, though he could see no good reason for it. The land looked right; he ploughed deeply, harrowed well, kept the weeds down, gave the cane plenty of water, could find no reason to complain of climatic conditions, but still did not get satisfactory results. Finally the head of the experimental station was consulted and an agricultural chemist was sent to the plantation. This chemist, after careful investigation, took samples of the soil from various parts of the land; these were analyzed and the source of the trouble was found to be the lack of potash. Just here it may be explained that when the same crop is taken from the land many years in succession, without adequate fertilization, some of the essential properties of the soil become exhausted. Speaking generally, these are lime, soda, potash, phosphates and nitrogen. In this particular instance, as has been said, the land had been gradually drained of its potash. The experimental station recommended the planter to scatter a certain fertilizer over his fields. This advice was followed and the next crop showed remarkable improvement, the yield of cane and sugar per acre being greater than ever before.

At one time the sugar industry of the Hawaiian islands was threatened with annihilation by a little insect called the “leaf-hopper.” The harm done by this pest was so enormous that one plantation having an average yearly crop of 19,000 tons was so severely affected that the yield dropped from 19,000 to 12,000, and then to 3000 tons in three successive crops. All the plantations on the islands suffered to a greater or lesser extent, and the entire sugar industry of Hawaii was jeopardized.

The hoppers punctured the stalks and leaves of the young cane, and in the holes thus formed laid their eggs by thousands. When the young hoppers hatched out, they fed on the juices in the stalk and in the leaves, thus destroying the leaves and depriving the cane of its protection and principal means of absorbing nourishment from the air.

As soon as the leaf-hopper by its ravages made itself known in the islands, the entomologists were consulted, and they were confronted with the task of studying the life and habits of the hopper for the purpose of finding, if possible, some other insects that would attack and exterminate it. It is well known to entomologists that every insect pest has natural enemies; the vital question in this case was—what were the natural enemies of the leaf-hopper and where were they to be found? Obviously, too, the problem was to discover insectivorous enemies that would not themselves attack the cane after they had destroyed the hopper.

After careful investigation it was concluded that the leaf-hopper had been introduced in Hawaii in new varieties of seed cane imported from Australia, and, as the hopper was not doing material damage on the plantations in Australia, the inference was that it must be controlled there by its natural enemy. The chief of the Department of Entomology was sent to London. There in the archives of the British Museum he found a full description of the leaf-hopper and that its native habitat was Queensland, Australia. On his return to Hawaii, entomologists were sent to Australia and the search for the enemy of the hopper began.

LEAF-HOPPER (GREATLY MAGNIFIED)

SUGAR CANE

For weeks the entomologists virtually lived in the cane fields, undergoing extreme privations, but at last their faithfulness was crowned with success. Several species of parasites that kept the Queensland leaf-hopper in check were discovered, and later on more were found in the islands of Fiji. These tiny creatures as a rule were invisible to the naked eye and could only be seen with the aid of a powerful magnifying glass. All of these insects were parasites either of the leaf-hopper or its eggs. Two of them were particularly efficacious. One, quicker in movement than the hopper, caught it unawares and attached itself to the hopper’s body much in the same way that a mosquito does to a human being. After catching it, the parasite would sting the hopper and lay an egg in its body. In a few days a young parasite was hatched from the egg, and so ravenous was this young insect that it devoured the hopper in a short time and then sought a fresh victim in which to lay its eggs.

The other insect was even more effective. It liked the hoppers’ eggs and for a long time found plenty in Hawaii to stay its appetite. As soon as the leaf-hopper laid its eggs in the cane, this particular insect would appear and lay its eggs in the eggs of the leaf-hopper. When the little enemies hatched out, they fed on the hoppers’ eggs and in turn laid their eggs in the eggs of the hopper. It came to pass that the hoppers, attacked by the parasite on the one hand and by the enemy on the other, rapidly dwindled in number until only a few remained, and these not enough to do material damage. As the hoppers and their eggs diminished, so did the parasite and the enemy, for the latter could live on insect food only.

How the scientists collected these tiny animalcules, kept them alive, transported them thousands of miles across the ocean, bred them in Hawaii and saved the Hawaiian sugar industry, reads like a romance.

The study of entomology is extremely interesting and the every-day business man rarely understands its importance. The finding, breeding and distribution of parasites of insect pests vitally affects the world’s food supply. The entomological name of the leaf-hopper family is Hemiptera, and Dr. Sharp, an authority on the subject, has said: “There is probably no order of insects that is so directly connected with the welfare of the human race as the hemiptera; indeed if anything were to exterminate the enemies of hemiptera, we ourselves should probably be starved in the course of a few months.”

It has been estimated by competent authority that the damage done in the world each year by the hemiptera, in spite of all their parasites, is conservatively $600,000,000. Were it not for the parasites, it would only be a year or two at most before every green leaf and spear of grass would disappear from the face of the earth. The direct influence of the practical application of this science to the production of sugar is readily apparent.

Pathology is almost equally important. In former years when cane failed to grow strong and sturdy and did not yield much sugar, the planter usually attributed the difficulty either to lack of water, poor soil, cool weather, too much rain or insufficient cultivation of the field by his manager, when in fact the trouble was due to none of these causes. He would personally oversee the operations of the following year, but with no better results.

EXPERIMENT STATION

PLANTATION SCENE IN HAWAII—LIGHT-COLORED FOLIAGE IS SUGAR CANE

When the roots of the cane became matted, stuck together and turned black, when a thick gum exuded from the stalk and leaves, preventing the plant from drawing proper nourishment from the air, it was thought that these troubles arose from climatic or local conditions, while in reality the plant was sick and needed a doctor. Today, under the new régime, whenever the plant shows any symptoms of ill-health, the pathologists are called in to eradicate the disease by scientific treatment.

Insect pests and plant diseases are generally brought into a country through planters sending to other cane-raising countries for new varieties of cane for seeding purposes that they think may produce more sugar than their own. Great trouble and heavy loss have been occasioned in this way and, as a consequence, the United States government has established a strict quarantine, allowing plant life to be landed only after rigid examination and when it is clear that no danger exists.

Another example of the work of the entomologists may be of interest:

During the visit of a well-known Hawaiian to Mexico many years ago, his attention was attracted by a beautiful shrub that he thought would make a splendid hedge around his home. It grew about five feet in height and its foliage was of a rich green, with a brown, red and yellow flower. The slips he brought to Honolulu thrived wonderfully and cuttings of the plant were taken to the other islands for a like purpose. Wherever planted it grew amazingly fast. It quickly spread over the hillsides and became so dense that cattle could not penetrate the thickets formed by it. It made valueless large areas of land that formerly had been used for the pasturing of cattle and plantation stock, and reduced the grazing area at an alarming rate. Land that adjoined the plantations and that in the course of time became needed for plantation purposes was also over-run by it.

The curtailment of the grazing lands and the increased cost of clearing were so great that the entomologists were finally sent for and asked if they could not eradicate the trouble. After a careful investigation they went to Mexico, whence the lantana, as the shrub is called, had come. On their return journey they brought back with them a fly. The fly laid its eggs in the bud of the lantana, and when the young flies were hatched they fed upon the lantana seeds. The flies multiplied rapidly and soon made away with the seeds, thus preventing the shrub from spreading any further. When it was once cleared from the land or the plantation it did not reappear.

These illustrations demonstrate the fact that the culture of sugar cane involves a constant struggle between science and unrestrained nature.

As a rule, Hawaiian sugar plantations are located close to the seacoast, between it and the base of the mountains. The lands slope gently toward the sea, thus insuring good drainage and easy application of water for irrigation. Most of the cane is grown on land less than five hundred feet above sea-level, although in a few rare instances it is cultivated at an elevation as great as three thousand feet. Parts of the leeward side of the islands, where it is extremely dry and hot, and where the cane thrives best, depend entirely on irrigation, the water being brought to the plantations by ditches or pumped from wells. On the windward side of the island of Hawaii, where the rainfall is abundant, irrigation is unnecessary except during very dry periods.

In cultivating, the ground is turned with steam ploughs to depths up to twenty-four inches. These ploughs are operated by powerful engines that work in pairs, one on each side of a field, usually from one thousand to fifteen hundred feet apart. One engine pulls a gang-plough across the field and the other draws it back. By this method the rich soil is thoroughly loosened and a wonderful vegetable growth results. Ordinarily in California the farmer ploughs only from four to six inches deep.

STEAM PLOUGH

PLANTING CANE

After the lands are ploughed and harrowed and all the weeds turned under, double mould-board ploughs are used to make the furrows in which the seed is planted. The furrows are not like those made for planting potatoes, but are about five feet apart and eighteen inches deep, each furrow and hill being symmetrical. They follow the contour of the land so that the irrigation water will fill the furrow and remain there until it is absorbed by the soil and penetrates to the cane roots. At regular intervals of about thirty-five feet, lateral ditches are cut, from which there is an entrance into every furrow. These lateral ditches deliver the water from the main ditches to the various parts of the fields. The land is now ready for the seed.

Meanwhile, the harvesting of the ripened cane in other fields is going on. As the laborers cut the cane, they top it, that is to say, they cut off about twelve inches of the upper part of the solid stalk. Sugar cane resembles bamboo, in that it is cylindrical in shape and divided every few inches into sections by rings or joints. In every joint there is a bud or eye, from which a shoot of cane will sprout, if properly planted in the ground and watered.

These tops, always cut from untasseled cane, contain very little sugar. They are carried to the newly prepared field and placed in rows in the furrows, end to end, lengthwise, the ends overlapping a trifle in order to guard against blank spaces in the growing cane. They are then covered, according to the season, with one to one and a half inches of earth, and the water is turned in until the furrow contains from three to four inches of water. Between six and ten days afterward, the little green cane shoots appear above the ground. From this time forward continuous irrigation and cultivation, together with proper fertilization, are required until the cane matures.

Planting usually begins in March and continues until September, sometimes later, and the cane ripens one year from the following December.

Growing cane should be watered every seven days, and the amount of water used for this purpose is enormous. For example: a plantation producing thirty-five thousand tons of sugar per annum needs twice as much water per day as the city of San Francisco.

The appearance of growing cane is much like that of Indian corn. The whole field area is covered with a dense, jungle-like vegetation of brilliant green. The leaves are long and narrow and hang in graceful curves. The cane grows so thick that it is almost impossible to crawl through it, and so seldom do the sun’s rays penetrate to the ground that rapid evaporation of the irrigation water cannot take place, hence the cane gets the full benefit of the moisture.

In certain varieties of cane, the great weight of the juice in the stalks causes them to bend, droop and take fantastic shapes. Sometimes they lie on the ground with the ends turned upward, and in fields where the stalks grow to a length of twenty-four feet, the average height of the tops above the ground is not over twelve feet. In other kinds the stalks stand straight up to a height of from eight to fourteen feet.

The production of cane per acre varies in different countries and in different parts of the same country, according to the character of the soil, climatic conditions, care and attention, use of fertilizer and amount of rainfall or irrigation. In Hawaii it ranges from twenty to eighty-five tons, and the amount of sugar obtained per acre runs from two and one-half tons to twelve tons, the average being about five tons.

Broadly speaking, lack of a normal amount of cane per acre, lack of sugar in the cane, or the prevalence of disease, is primarily due to an unsanitary or unsuitable condition of the soil. This can usually be corrected by proper cultural methods, such as adequate aeration of the soil, the turning under of the cane tops and leaves, application of lime and suitable combinations of fertilizing ingredients. Fundamentally, cane requires a well-aerated, moist, alkaline soil and a fertilizer in which the nitrogen content is high and in excess of the potash and phosphoric acid. It is found that nitrate of soda, when applied alone or in combination with potash and phosphoric acid, produces a very strong growth. The proper sanitation of the soil tends to promote the beneficial bacterial action so essential to the growth of the cane.

IRRIGATION DITCH—SHOWING TUNNEL

IRRIGATION DITCH

In December and January the cane tassels or flowers, which indicates that it has about reached maturity and is ready for cutting. Thenceforward very little irrigating is done, as additional water applied at this time might retard ripening, which would mean a reduced amount of sugar stored up in the cane.

It is interesting to note that while the cane is growing and in an unripe state, there is no discernible sucrose or pure sugar in it. As the ripening process goes on, the content of the cane juice is changed by the action of the sun’s rays, and the amount of sucrose as determined by polariscopic test shows when the time for harvesting is at hand. Nature’s operation in thus changing glucose or invert sugar into sucrose or pure sugar cannot be accomplished by any human means.

The harvesting then begins and continues until the end of July or August. Usually the field is set on fire before cutting. On account of the great amount of moisture or juice in the cane, the stalks do not burn, but the leaves are thoroughly consumed. This operation eliminates a good deal of leaf material that is not only useless, but which, if sent to the mill, would increase the cost of crushing, besides absorbing a certain quantity of the juice expressed from the cane.

Formerly men stripped the leaves from the cane in the fields, but it was a difficult matter to accomplish such work, and the cost was heavy. An accident changed the method of doing this work. A field took fire and it was found that while all the leaves were consumed, little or no damage was done to the stalks provided they were cut promptly and sent to the mill to be crushed. The practice of burning has since become general, although the advisability of continuing it is now being given very careful study.

Burning eliminates the arduous labor of stripping, and no doubt does away with many harmful insects and fungi, but at the same time it destroys the enemies and parasites of these insects and this loss is severely felt. Another disadvantage of burning is that the nitrogen contained in the cane leaves is liberated and not returned to the soil as would be the case if the leaves were stripped and ploughed under. In the latter case the leaves rot rapidly, add humus to the soil, help aeration, and improve the sanitary condition, all of which tends to increase the yield of cane per acre. From recent experience it is not improbable that burning will be discontinued in the near future.

As soon as the field is ready, whether burned or not, the laborers go in to cut the cane. A long, heavy knife is used. The cutter grasps the stalk and drives the knife into it, severing it just at the ground. He then tops it, that is, he cuts off the upper part that contains no sugar, and, to aid in subsequent handling, the long stalks are cut into convenient lengths.

As the burning destroys the eyes or buds, certain fields are cut and topped for seed before the burning takes place.

There are two general methods of transporting the cane to the mills. One is by rail and the other by flumes. On the irrigated plantations where water is never overplentiful, railroad tracks and locomotives are invariably employed, while on the non-irrigated plantations, located in districts where there are copious annual rains, V-shaped flumes are extensively used. In some cases a combination of both systems is adopted to advantage. From the upper lands where it is difficult to construct railroads, the cane is flumed to a convenient point on the railroad system, at a lower elevation, and delivered into cars, while the water is conducted into ditches and used for irrigating the lower cane lands.

YOUNG SUGAR CANE

RIPE SUGAR CANE—SHOWING TASSELS

In the case of rail transportation, paths one hundred and fifty feet apart are cut through the fields so that temporary railroad tracks may be laid and cars run in and loaded on these tracks. The whole field is then cut in the same way and the work continued until the entire crop is harvested.

The loaders follow up the cutters. These men lay a strap on the ground and pile the stalks on the strap until they have a bundle of cane weighing from seventy-five to one hundred pounds. With a dexterity born of long practice, they sling a bundle upon their shoulders and carry it up an inclined runway to a railroad car not over seventy-five feet away and dump it on the car. The cutting and loading are usually done by contract, at so much per ton, and it is remarkable how proficient the men become.

When flumes are used exclusively, much the same methods are adopted. Paths are cut through the fields and in these paths are placed the flumes which, like the temporary railroad tracks, are moved from time to time as necessity demands. The mill is located at the lowest point on the plantation and the flumes are placed so as to insure a good grade from the cane fields on the uplands to the mill below. The flumes are either carried on low trestles or run along the ground, but always at a height which enables the laborers to throw the cane into them conveniently.

Water is turned into the upper end of the flume and, rushing rapidly down, carries or floats the cane to the mill. Cane is flumed in this way for distances up to seven miles at low cost and with satisfactory results.

The cars when loaded in the fields are made up into trains and hauled by locomotives to the mill, which is generally located about the center of the plantation, or at a point where most of the cane can be delivered on a downward grade. Each car is carefully weighed on a track scale and the exact quantity of its load of cane is ascertained and recorded.

For years past the planters have been offering large rewards for the invention of a machine to cut and load the cane, but the old hand method is still employed, although some experimental loading machines are meeting with more or less success, but none are in common use.

The problems involved in cutting cane by machinery seem insurmountable, and, while many devices have been tried, not one has proved successful.

After the cane is cut the first time, ploughs are sent through the fields and a furrow is ploughed along each side of the stubs of the cane which are left in place. This ploughing opens up the ground, aerates the soil, and affords the irrigating or rain water a means of easy access to the cane roots. The water tenders follow up the ploughs and the furrows are filled with water, which is gradually absorbed by the old cane roots left in the ground. In time new sprouts spring up from buds on the old stalks of the cane and another growth begins. The second crop is called “first ratoons” and, when cultivated for a single year only, it is designated “short ratoons.” As a rule it does not yield as much sugar as plant cane, but the saving in seed, in the preparation of the fields and in other labor frequently makes up for the reduced amount of sugar. If allowed to grow for two years, as is generally the case, it is called “long ratoons” and produces proportionately more sugar. In the past a very large percentage of the Hawaiian crop was planted with fresh seed every year and but a small percentage ratooned. Nowadays, however, the tendency is to ratoon the crop as long as the yield justifies, which in many cases is from three to four times. In Cuba the cane when once planted is ratooned for many years.

There have been specific instances in Hawaii where ratoons that have been allowed to grow for two years (long ratoons) have shown a better yield than the first planting. According to the best information, this is due to the presence of poisonous matter in the ground, turned up for the first time at the first planting.

CUTTING CANE

LOADING CANE

The object of all the ploughing, weeding, cultivating, fertilizing and irrigating, is to produce a large number of strong, sturdy stalks of cane, yielding a maximum amount of sugar. The sugar is contained in solution in the sap or juice and the amount can be materially increased by due care and attention.

As some of the elements which form the plant are absorbed from the air through the leaves, favorable climatic conditions are essential to its full growth and development. Proper fertilizers must be added to the soil, and water applied regularly and in sufficient quantity.

Commercial fertilizers are used in Hawaii probably to a greater extent than in any other country in the world. It is quite common for plantations to use half a ton of fertilizer per acre per crop, and at times as much as two thousand pounds per acre. The yearly fertilizer cost per acre will probably average twenty-five dollars.

As it takes eighteen months for a crop to mature in Hawaii, it will readily be seen that the plantation area must be at least double that used for any one crop. While one crop is being harvested, another crop is in the ground growing. As soon as the cane is cut, the lands are immediately prepared for replanting or ratooning, as the case may be. During certain periods each year, usually in June and July, a visitor on an Hawaiian plantation can see one crop growing, one being harvested and one being planted.

From the foregoing it will be seen that the harvesting begins in December and ends in July or August. The planting begins from March to June and usually ends in September, according to plantation conditions and whether or not the land is irrigated.

THE MANUFACTURE OF RAW SUGAR

The details of the manufacture of raw sugar from cane and of sugar from beet roots differ, but there are several processes common to both. The operations necessary for making raw cane sugar are as follows:

  • 1. The extraction of the juice.
  • 2. The purification of the juice.
  • 3. The evaporation of the juice to syrup point.
  • 4. The concentration and crystallization of the syrup.
  • 5. The preparation of the crystals or grains for the market by separating them from the molasses.

Every mill has an extensive laboratory where skilled chemists are constantly engaged in sampling and analyzing cane, raw juices, syrups, sugars and molasses. In fact the chemical work is a most important feature in the raw-sugar house, beet-sugar factory or refinery. The superintendent should be an expert chemist, as the proper recovery of the sugar from the cane and beet juices is wholly dependent upon the technical control of manufacturing processes.

EXTRACTION

After passing the scales, the cars containing the cane are switched alongside the carrier which feeds the cane into the mills. Before the cane is unloaded, however, samples are taken from each car and sent to the laboratory, where they are carefully analyzed. The amount of sugar present is ascertained, as well as the quantity and quality of the juice in the cane. It is, however, impossible to get a fair average sample of the cane in this way, and therefore the efficiency of the mill work is determined on the basis of an analysis of the juice and the fiber after it has passed through the crushers.

TRAIN-LOAD OF CANE READY FOR THE MILL

A MODERN MILL

The carrier just referred to is a wide slat conveyor, running alongside the railroad tracks in the yards to a point directly over the first set of crushers. The cane is taken from the cars by a mechanical unloader, the arms of which reach out and with distended fingers pull the cane stalks off and land them on the slow-moving carrier, which takes them onward and upward to the crusher.

The crusher consists of two large rolls, with immense interlocking, corrugated teeth on the circumference of each. These rolls are set close together, and the cane passing through is broken into short pieces and matted to an even layer. The juice squeezed out by this preliminary crushing runs through a metal trough into a large receptacle known as the juice tank.

From the crusher the mat of cane passes to the mills proper. These mills consist of from nine to eighteen rolls, about thirty-four inches in diameter and seventy-eight inches long, arranged in groups of three, set in the form of an isosceles triangle, one above and two below, one set following the other in a direct line. The lower rolls are parted enough to allow the expressed juice to fall through them, while the half-crushed cane is carried over by means of an iron bar called the returner. The faces of the rolls are more or less roughened, or grooved, so as to draw the cane through and give a better crushing action. They are turned slowly by powerful engines, which transmit the power to each set of rolls through a system of gears. The rolls are forced together by hydraulic rams exerting a pressure of from four hundred to six hundred tons. It is this tremendous pressure that squeezes the sugar-bearing juice out of the cane.

From the crusher the matted cane passes through the first set of rolls, where a large percentage of the remaining juice is liberated. This is caught in a metal trough and, after passing over a fine screen to remove the small pieces of cane, runs to the juice tank. The cane passes through the second set of rolls, thence to the third set, and so on to the end of the mill. In front of the last set of rolls, hot water is sprayed on the cane to soften the fiber and dilute the remaining juice, thus aiding the final extraction. The adding of hot water is termed maceration. By the time the cane has passed through the last set of rolls, all the economically recoverable juice is out of it and delivered into the juice tank, with the exception of the juice and maceration water from the last set of rolls, which is always returned to the preceding set of rolls for maceration purposes. The juice or maceration water coming from the last set of rolls contains very little sugar, and the object is to secure greater concentration by using it for double maceration instead of adding that much additional water which would have to be evaporated later on in the process.

In well-designed, modern mills, with cane carrying not over twelve per cent of fiber, more than ninety-eight per cent of the sugar in the cane is extracted, the remainder being left in the fiber. This is almost perfection today. What it will be tomorrow no one can say.

The fibrous, woody part of the cane, or bagasse as it is called, is comparatively dry as it leaves the last rolls. It is conveyed from the mills to the boiler house on a wide slat conveyor, and fed directly into the furnaces under the boilers that generate the steam for power and boiling purposes. A modern raw-sugar mill requires practically no other fuel than that obtained as a by-product from the crushing of the cane.

The boiler plant is usually of large capacity, as a great deal of steam is required to drive the engines that run the crusher, the rolls, the electric lighting system, the pumps and other machinery. Besides, a large amount is needed to evaporate the water in the juice and to boil and dry the sugar. The ashes from the furnaces are returned to the fields as fertilizer, so that very little is lost.

CANE CARRIER AND MECHANICAL UNLOADER

ANOTHER TYPE OF CANE UNLOADER

PURIFICATION

The juice as it comes from the mills contains impurities such as dirt from the fields, small pieces of cane stalks and other foreign matter, besides salts, gum, wax and albumen. It is necessary to remove as many of these substances as possible, and this is where the chemist’s work begins.

So long as the juice is confined in the living cells of the cane it does not quickly ferment, but when liberated it rapidly undergoes such change. Therefore no time is lost in arresting this action. The juice is pumped to the top floor of the mill and there a solution of milk of lime is added in sufficient proportions to neutralize the acidity. The mixture is then heated in closed tanks under pressure to 215 degrees Fahrenheit. The heat causes the lime to combine rapidly with the gums and salts in the juice, and the albumen to coagulate.

The hot juice is then run into large settling tanks, where the insoluble solids and the albumen sink to the bottom, carrying with them vegetable and other matter suspended in the juice. Certain foreign substances of light specific gravity float to the surface in the form of scum.

After settling for a time the clear juice is drawn off and the scum, mud and cloudy liquor left in the tank. As a vast amount of liquor must be handled every hour, it is not practicable to have tank capacity great enough to admit of the liquor standing a sufficient length of time for every particle of foreign matter to settle, so as an adjunct to the settling tank, filters are used. These are cylindrical iron tanks, packed tightly with ordinary wood fiber, known as excelsior. The juice is conducted to these filters, and as it percolates through the excelsior, practically all of the remaining foreign matter is caught and retained in the fiber. The clear juice is then run to the receiving tanks for the evaporators and the mud and scum that remain are drawn off into mud tanks, where more lime is added and the mass stirred up. Finally it is delivered to the filter presses, where the mud and other impurities are taken out and the clear liquor containing sugar is sent to the evaporators.

Another method for cleaning, called “precipitation in motion,” is to carefully lime the juice and then heat it in closed vessels and under sufficient pressure to carry it through a pipe to large insulated settling tanks.

These settling tanks, usually of sheet steel, are made in the form of truncated cones with conical bottoms, the small diameter of the tank being at the top. Suspended in the center is a vertical cylinder somewhat less in diameter than the upper part of the tank. This cylinder extends downward about eight feet to a point opposite the largest diameter, which makes the area between the circumference of the suspended cylinder and the tank at that point very much greater than the area of the cylinder itself. This difference in area is necessary to retard the flow of the juice and allow the sediment, mud and insoluble solids to be deposited at the bottom of the tank.

The juice is delivered by a pipe into the top of the cylinder which projects a few inches above the edge of the surrounding settling tank. It passes slowly down the central passageway, turns at the bottom, where its speed is materially slackened, and goes out through a pipe line connected to the side of the tank just below the upper edge.

There are several other methods in general use, but in all of them the principle of settling, upon which the separation or cleaning depends, is the difference in specific gravity between the juice and the dirt. A high and even temperature should be maintained by preventing radiation, as lowering the temperature would increase the specific gravity and viscosity of the juice without increasing that of the dirt in equal proportion.

TWELVE-ROLLER MILL

MODERN CRUSHING PLANT—TWO FIFTEEN-ROLLER MILLS AND CRUSHERS. CAPACITY, ONE HUNDRED AND FIVE TONS PER HOUR

There are many different types of filter presses, but those at present in general use are long, oblong machines, set horizontally on the floors, with layers of corrugated iron plates, covered with canvas sheets, between which are hollow frames so arranged that the juice will pass from the hollow frames through the canvas to the corrugations in the plates.

In passing through the presses under pressure the sediment, scum and other impurities are caught on the canvas sheets and the clear juice passes through the canvas, down the corrugations and out through small holes in the plates controlled by valves on the outside of the presses, from whence it runs to the evaporator tanks. The sugar in the mud caught in the hollow frames is washed out of the mud with water and is sent to the evaporator, while the mud itself is finally returned to the field, to be used as a fertilizer.

The clarified juice from the settling tanks, filters or presses, is light brown in color, but is thin and watery, and must now be reduced to syrup point. All the suspended impurities have been removed, but some impurities in solution and the original coloring matter still remain. Some of these foreign substances are subsequently eliminated during the process of crystallization in the vacuum pans described later on.

The object to be attained in a raw-sugar house is the production of a sugar containing ninety-six per cent of sucrose, and there is little or nothing to be gained by carrying the process of manufacture beyond the stage that insures such result.

The final extraction of all the impurities and the conversion of the impure raw into pure white granulated sugar is the work of the refiner, which is dealt with in a subsequent chapter.

From the time the juice leaves the cane until it is crystallized it is kept at a high temperature, as cold juices or syrups are viscous and run slowly. High temperatures kill germs, prevent fermentation and expedite manipulation.

EVAPORATION

Under ordinary atmospheric pressure at sea-level, water boils at a temperature of 212 degrees Fahrenheit and sugar juice at a few degrees higher, according to its density. This temperature if long applied to sugar juice would tend to burn and destroy the sugar, but the juice can be heated to 250 degrees for a short time without deterioration.

The clarified juice contains about eighty-five per cent of water and fifteen per cent of solid matter. A large proportion of the water must be removed by evaporation. To accomplish this under ordinary atmospheric conditions would require heat increasing from 212 degrees Fahrenheit, as the solution increased in specific gravity above the standard of pure water. This would require a large amount of fuel, and the juice would also be more or less adversely affected by long maintenance of comparatively high temperature.

To obviate these conditions the juice is boiled in a multiple evaporator, the invention of Norberto Rillieux, whose first construction in New Orleans in 1840 was a double effect horizontal submerged tube apparatus which has since undergone many changes and improvements. The theory of evaporation in vacuo was extended to two or more cells or vacuum bodies, using the steam or vapor from the first to heat the juice or syrup in the second and so on. At the present time the quadruple effect, or four-cell evaporator, is most commonly in use, although sextuple effects are not rare. The ordinary practice is as follows:

The juice enters cell No. 1 and covers the heating tubes, to which is admitted sufficient steam—generally exhaust from the engines—to cause the liquid to boil. The steam or vapor liberated from this first boiling is conducted through the vapor pipe directly into the heating tubes of cell No. 2, while the juice from cell No. 1 is passed into the second, or cell No. 2, and surrounds the heating surfaces which contain the hot vapor given off from the same juice in cell No. 1.

DELIVERING BAGASSE TO FIRE-ROOM

GENERAL INTERIOR VIEW OF MODERN RAW-SUGAR MILL

As there is little or no pressure above the liquid in the first cell, the juice boils at from 215 degrees to 220 degrees Fahrenheit. By maintaining a vacuum of five inches in the second cell, the temperature at which the liquid will boil is reduced to 203 degrees, and the vapor from cell No. 1 is hot enough to boil the juice in cell No. 2 without any addition of heat. The vapor from cell No. 2 in the same way enters the heating tubes of cell No. 3, while the juice entering this cell is exposed to a vacuum of fifteen inches, which reduces the boiling temperature to 180 degrees, so that the difference of 23 degrees between the conditions of cell No. 2 and cell No. 3 causes a third boiling and evaporation without any additional steam being added.

A vacuum of twenty-six inches in the last cell, No. 4, brings the final boiling temperature down to about 150 degrees. The vapor from this last cell enters a condenser, where it is exposed to a spray of cold water, is condensed and passes down a pipe not less than thirty-four feet long, terminating in a water seal, and called the Torricellian tube, after Torricelli, who discovered that mercury would rise thirty inches in a tube while water would rise thirty-four feet with a perfect vacuum.

The juice in passing through these evaporating cells is boiled to a syrup containing about thirty-five per cent of water and sixty-five per cent of solid matter. It is pumped out of the fourth cell into the receiving tank for the vacuum pan.

This quadruple system of boiling only requires about one-fourth the amount of heat that would be necessary to do the same work in a single vessel. As the evaporators operate continuously, a constant level of the boiling liquid is maintained in each cell, the juice being drawn from one to the other by increasing vacuum and controlled or regulated by means of valves.

A powerful vacuum pump draws the air and other incondensable gases from the condenser and maintains the vacuum, which is applied to the necessary extent in each cell. The heating tubes are connected to drain pipes, which remove the condensed vapors.

Vacuum, simply and concisely stated, is the absence of air or gas. It is usually obtained by pumps which suck the air or gas out of closed containers or pipes. No doubt many of the readers in their younger days have sucked on the end of a bottle and were amused to find the bottle hanging on the end of the tongue. It was the vacuum, or lack of air in the bottle, which caused it to hang thus. The outside atmospheric pressure (which at sea-level is fifteen pounds per square inch) was doing its best to gain an entrance through the tongue into the bottle from which the air had been extracted.

The pumps simply suck the air out of the containers or pipes and discharge it through valves, in much the same way that the air was sucked out of the bottle. It must be remembered, however, that in boiling water or juice, the vacuum is being continually broken or reduced by the liberation of air and gases from the juice, steam and condensing water. This action must be overcome by the constant work of the vacuum pump.

To determine the amount of vacuum carried in any container, a small mechanical contrivance, known as a vacuum gauge, is used. This, in its simplest form, is a bowl of mercury with a long glass tube leading from it. If the upper end of the glass tube is attached to the container from which the air is to be drawn, the mercury in the tube will rise in proportion to the amount of air extracted. When an absolute vacuum has been formed, the mercury in the glass will stand at a height of thirty inches.

FILTER PRESSES

SET OF QUADRUPLE EVAPORATORS

In commercial operations a vacuum greater than twenty-eight inches is seldom required, as this is sufficient for all practical purposes. The degree of vacuum for any container can be varied easily by mechanical manipulation, so that a vacuum anywhere from one to twenty-eight inches may be maintained.

CONCENTRATION AND CRYSTALLIZATION

From the receiving tanks the syrup is drawn into the pans by a vacuum ranging between twenty-five and twenty-seven inches. The pans are large cast-iron or copper cylinders, standing in a vertical position, with dome-like tops and conical bottoms, almost spherical in shape. Leading from the top is a large pipe through which the vapors from the boiling are drawn off and condensed. On the conical bottom is a large valve, which may be opened when the boiling is finished to allow the massecuite (a French term meaning cooked mass) to drop out.

At regular intervals in the height of the pan there is a series of copper coils, connected with a steam line at one end and a drain line at the other.

The general principle involved in boiling sugar is the separation of the sucrose contained in a solution from the impurities present in that solution, and this is accomplished by evaporation and concentration through the agency of heat. After the sugar is once formed in definite crystals these crystals attract and appropriate the sucrose in solution in the process of building up the crystal structure, while repelling or excluding the impurities, so that, as a consequence, the latter remain in solution. The crystals thus formed are subsequently removed from the solution by means of centrifugal machines. Crystallization, whether in a pure or impure solution, will proceed to only a certain extent, and will only partially remove the sucrose from the solution in one boiling, the limit of crystallization being governed by the amount and nature of impurities present.

The process of boiling is begun by drawing some of the concentrated juice into the pan and turning steam into the coils, which starts the boiling. This is continued until the supersaturation is such that minute crystals of sugar form or “grain out.” By properly timed admissions of fresh concentrated juice, drawn into the pan by vacuum as before, the crystals grow in size and at last the pan becomes filled with a mass of sugar crystals of regular shape and size, immersed in a thick “mother liquor” containing sugar and the impurities that were not removed by the filters or settling tanks.

The size of the grain may be varied at will by the operator in charge, who is known as the sugar boiler. After the grains are once formed, their number (if the sugar boiler is an expert) does not increase, but the size does, as the original grain continually builds up on itself from the outside.

The question may be asked, why is all the moisture not boiled out in the pan and the sugar dropped in a dry, crystallized state? There are several reasons why such a course is impracticable; first, because the impurities, which must be eliminated by crystallization and which are carried off in the mother-liquor, would be boiled into the sugar and make it unsalable; second, because to aid crystallization and prevent scorching or burning on the hot steam coils the mass must be kept in active circulation during the boiling process, or, long before all the moisture could be driven off, a large part of the contents of the pan would be burned on the coils; and third, even if it were practicable to boil the contents down to a solid state, the grains would stick to each other and become one solid mass, which would have to be removed from the pan with bars, picks or chisels. Enough moisture, or rather liquor, is left in the mass to enable it to flow from the pan by gravity. This liquor, with the impurities it carries, is subsequently removed from the sugar by a drying or separating process which will be explained later on.

Massecuite is a viscous, sticky, semi-fluid mass of the consistency of half-formed ice.

VACUUM PANS

CENTRIFUGAL MACHINES

The reason sugar “grains” is because the water in the juice has the power to hold in solution only so much sugar. As it goes into the pan, the juice is almost a saturated solution, and as the water is driven off by evaporation, the solids that up to this point have been in solution must of necessity crystallize.

When the sugar boiler decides that the “strike,” that is, the massecuite contained in the pan at one boiling, is satisfactorily grained, he breaks the vacuum by opening a valve on the top of the pan, thus allowing the air to enter. He then opens the valve at the bottom of the pan and the mass drops into a long tank with a rounded bottom, called the mixer, in which a shaft, equipped with paddles, is revolving. The paddles are for the purpose of keeping the mass agitated and in an even condition. The agitation prevents the grains from dropping to the bottom of the tank and forming a solid block, called concrete.

PREPARATION OF CRYSTALS FOR THE MARKET

From the mixer the massecuite runs through spouts into the centrifugal machines. Centrifugal machines are cylindrical-shaped, perforated brass baskets, usually forty inches in diameter and twenty-four inches deep, hung on a central shaft suspended from beams overhead, and surrounded by a solid outside curb or casing.

On the shaft is a pulley, which is driven by a belt connected with an engine or an electric motor. The inside of the basket is lined with a fine-meshed brass screen, which retains the grains of sugar, but allows the liquor to escape freely into the outer casing.

As soon as the centrifugal machine is filled with massecuite from the mixer above, the power is turned on and the machine begins to spin around at an increasing speed until a velocity of one thousand revolutions per minute is reached. The centrifugal action forces practically all the liquor out through the screen and leaves in the machine all the grains of sugar that were formed in the pan. A little dry steam is sometimes turned in to assist in reducing the moisture in the sugar.

The centrifugal is then stopped, a valve in the bottom is opened, and the nearly dry crystallized raw sugar is dropped into bins. From the bins it is drawn off through spouts and packed in sacks containing about one hundred and twenty-five pounds each.

It has been demonstrated that raw sugar containing a large amount of moisture inverts or deteriorates more rapidly than that with a low-moisture content. It is apparent that as moisture adds to the weight, the transportation charges, which are based on tonnage, are greater in the case of wet sugar than in the case of dry. In many of the modern mills, therefore, a further treatment is given the sugar to reduce loss by inversion and lessen freight charges.

From the bins last mentioned the sugar is dropped into revolving drums six feet in diameter and twenty-six feet long, set at an incline so that as the drum revolves the sugar is carried round to the highest point on the circumference of the drum and dropped to the lower side, at the same time traveling from the receiving to the discharging end. The shape, motion and inclined position of the drum cause a perfect shower of sugar in the drum for its entire length and breadth. While it is revolving a current of hot, dry air is drawn through the drum by means of suction fans, and as a result the moisture in the sugar is absorbed by the air and carried out of the building. At this stage the product has a good hard grain of a yellowish-brown color; contains from ninety-six to ninety-seven per cent of pure sugar and about one-half of one per cent of moisture.

FILLING, WEIGHING AND SEWING SACKS

TRAIN-LOAD OF RAW SUGAR LEAVING MILL

From the end of the revolving drum the sugar is drawn off into sacks holding about one hundred and twenty-five pounds each. These sacks are sewed by machinery and put into railroad cars to be hauled to the docks at the shipping port, where the cars are switched under huge hoisting cranes or alongside speedy conveyors which carry the sugar into large seagoing steamers especially built for the trade. Some of these ships have a cargo capacity of two hundred and twenty thousand sacks, and they transport the sugar to the buyers on the mainland in San Francisco, New York or Philadelphia, as the planter directs.

The liquor thrown off by the centrifugals is not lost; it is taken back to the pans and reboiled. After this has been done several times and most of the sugar extracted, the purity is so low and the sugar content so small that it does not pay commercially to reboil further, and the residue is sold as molasses. It contains about thirty-five per cent of sugar and from twelve to fourteen per cent of invert sugar, or glucose, as it is generally called.

Some of the waste molasses is mixed with fodder and tender cane tops and fed to cattle and plantation stock, the sugar content proving of great value as a fattening agent and energy builder. Part of the molasses is sprayed on the bagasse as it leaves the crushers and serves, first, as a fuel under the boilers, and, second, as a fertilizing agent in the form of ashes after it has been burned. During the past few years much of it has been shipped in tank steamers to the mainland, where it is used for the manufacture of spirits and vinegar, and also as the principal ingredient in prepared stock foods which are much in demand today.

Every bag of sugar shipped from the plantation is marked to indicate the plantation from which it came. The net weight of the sugar in each bag is recorded, a sample of the sugar taken and its sucrose content ascertained, for it is on the basis of weight and sucrose content that raw sugar is bought and sold.

From the beginning to the end of the process of manufacture, chemists are vigilantly alert sampling, testing, analyzing and supervising the operations. Records are made of all analyses, temperatures, purities, densities, extractions, etc., and the results tabulated for future reference.

The average cost in Hawaii of preparing the fields, planting, irrigating, fertilizing, cultivating and cutting the cane, manufacturing the sugar and delivering it in the New York market, is about $56.00 per ton of two thousand pounds.

TRANSPORTATION AND DELIVERY OF RAW SUGAR

It has been explained that in Hawaii sugar is packed in one-hundred-and-twenty-five-pound sacks. Methods and customs vary in different countries. For instance, in Cuba it is put up in large gunny bags, each holding an average of three hundred and twenty-five pounds. The same custom prevails in Porto Rico. In Peru, and to a limited extent in Java, sacks containing two hundred and twenty-four pounds are used. A large part of the sugar in Java, however, is put up in bamboo baskets of native make, containing from five hundred to eight hundred pounds. They are about thirty inches in diameter, from thirty-six to forty-eight inches high, and are lined with coarse leaves to prevent the sugar from sifting out between the weavings of the bamboo. Philippine sugar is packed in leaf-lined mats of tough vegetable fiber, each holding about seventy pounds.

These various styles of containers necessitate different methods of handling to and from the ships and by the buyers, but Hawaii will again serve as an example of efficient, modern practice. Outside of what is consumed locally, all Hawaiian sugars are shipped to the mainland of the United States by steamers or sailing vessels to San Francisco, or by steamers to New York or Philadelphia, via the Panama canal.

As sailing vessels are rapidly disappearing from the seas so far as the sugar trade is concerned, reference will be made to steamer traffic only. The steamers are specially built for carrying sugar, having a cargo capacity of from five thousand to thirteen thousand tons, and the best loading and discharging facilities.

When loading in Honolulu, the steamers usually lie alongside wharves covered with immense warehouses, where rapid-speed conveyors carry the sacks of sugar to a point above the ship’s hatches and drop them into chutes which guide them down into the hold of the ship, where they are compactly stowed. On the off-shore side of the vessel small steamers from other island ports lie alongside and hoist the sacks by means of steam winches to a point over the hatch and deposit them in similar chutes. When steamers are loaded from both sides in this manner, as much as three thousand tons, or forty-eight thousand sacks, can be loaded in nine hours.

After a vessel is completely loaded and gets her clearance from the custom house, she departs for San Francisco, twenty-one hundred miles away, or for the Atlantic seaboard, via Panama, as the planter may direct.

The voyage ended, and the quarantine and health regulations complied with, she proceeds to the dock of the buyer, usually a sugar refiner. The Hawaiian planter invariably sells his sugar under contract prior to arrival of the vessel at destination.

Planters in other countries operate differently. Occasionally sugar is sold on the plantation at an agreed price, and the buyer arranges his own transportation. The planter sometimes ships his sugar unsold and negotiates its sale while it is en route. If so sold, it is delivered directly to the buyer on arrival; if not, it must be stored in a warehouse at the planter’s expense pending sale.

The practice of the Hawaiian planter is to sell his sugar to refineries in San Francisco, New York or Philadelphia, under contracts extending over a term of years. It is agreed that the sugar shall be shipped as soon as made and that the refiner will receive it immediately on arrival, the price for each cargo being that quoted in the open New York market for ninety-six-degree centrifugal sugar on the day preceding its arrival.

STEAMER LOADING SUGAR ALONGSIDE DOCK

LOADING SUGAR AT AN OUTPORT IN HAWAII

The value of raw sugar, like that of other staples, is based on supply and demand, and the price fluctuates from day to day according to the requirements of the refiners or the necessities of the sellers.

There are certain rules or trade conditions governing all sales, so that when one man buys and another sells at an agreed price, each knows what he is bargaining for. For instance, raw sugar is bought on the ninety-six-degree centrifugal basis, that is, the price agreed to be paid is for centrifugal sugar containing ninety-six per cent of sucrose. If it contains more sucrose, a higher price is paid; if it contains less, a lower price is paid; all according to an established scale of additions and deductions. Then again, the time of payment for the sugar is well understood. It is usually ten days after the sugar has been finally discharged from the ship, as this allows a sufficient period in which to determine the exact weight of the sugar and the percentage of sucrose it contains. An instrument called a polariscope is invariably employed to determine the amount of sucrose present and the results obtained from its use are absolutely accurate. A description of the operation will undoubtedly prove interesting.

POLARIZATION

The practical working of the polariscope is based upon the property of sucrose to rotate a ray of polarized light to the right.

Ordinary light is the effect on the eye of vibrations of the ether. These vibrations occur in all directions, but by certain optical devices they may be confined to a single plane, and light thus confined is called polarized. If rays of polarized light pass through a layer of certain bodies, e. g., quartz, sugar and many others, the plane in which the vibrations occur is rotated, and the polariscope has been devised for the purpose of measuring the rotation of the plane of polarization.

Polarized light, as used in the polariscope, is obtained from the Nicol prism or some development of it. Ordinary light passing through crystals of certain bodies, of which Iceland spar is an example, is split into two rays, one of which is known as the ordinary and the other as the extraordinary ray. A Nicol prism is made of two wedge-shaped pieces of Iceland spar, cemented together with a film of Canada balsam.

The accompanying sketch gives a good idea of the arrangement of an ordinary polariscope.

POLARISCOPE

A strong white light, e, enters the instrument through a lens at f, to the Nicol prism b, by which it is polarized. The ordinary ray is dispersed, while the extraordinary or polarized ray passes straight through and enters the sugar solution contained in the tube c, which has glass ends. In passing through this solution it is given a rotary motion to the right or to the left, according as the sugar in the solution is sucrose or levulose. When it emerges from the tube containing the sugar solution, the now rotated polarized ray encounters a second Nicol prism, of which one of the wedges is fixed and the other movable. This prism is called the analyzer. A pointer, controlled by a thumb screw, is attached to it, and when the correction of the polarized ray’s rotation has been made with precision by adjustment of the wedges, the pointer will indicate directly and accurately on a scale the amount of sucrose in the solution under test, because the polarized ray was rotated in exact proportion to the amount of sucrose contained in the solution through which it passed.

The polariscope is made and set so that a standard weight of pure sugar (C₁₂H₂₂O₁₁), dissolved in a standard quantity of pure water, and placed in a tube of given length, will rotate the ray of polarized light in passing through, to a point on the scale marked one hundred degrees, the equivalent of per cent. Also, that by using the same quantity of water, but twenty-five per cent, fifty per cent, or seventy-five per cent less weight of sugar, the rotation will show seventy-five degrees, fifty degrees or twenty-five degrees of pure sugar, as the case may be.

A sample is drawn from each bag of sugar and all of these go to make up a general average sample. The standard quantity is carefully weighed, dissolved with the standard amount of water, clarified, filtered and poured into a tube with glass ends, which is then inserted in the polariscope between the eye of the operator and a strong artificial light. When the operator making the test applies his eye to the instrument, he sees a distinct shadow on a lens in the line of vision, one side being light and the other dark. He then turns the thumb screw which adjusts the analyzer until the whole field of vision is neutral, which indicates that the rotation of the polarized ray has been corrected. The pointer on the scale now shows the exact percentage of sucrose present in the raw sugar, ninety-four, ninety-five, ninety-six degrees, or whatever it may be. This test determines the real value of the sugar, based on the market quotation for ninety-six-degree sugar. If the polarization should show exactly ninety-six degrees, the price to be paid for the sugar and the market quotation will be identical.

In most sugar-producing countries the government imposes an import tax on all foreign sugars, in order to obtain revenue to defray governmental expenses and to protect the domestic industry, if any, against competition with other countries in which cost of materials and labor may be lower. Commodities produced in a country naturally add to its development and wealth, and this explains the fostering of the sugar industry by various governments.

The United States duty on foreign sugar is at present $1.256 per one hundred pounds of ninety-six-degree raw sugar. On account of our treaties with Cuba, the Cuban planter is allowed a deduction of twenty per cent, and, therefore, pays a duty of $1.0048 per hundred pounds, which, owing to trade conditions, is the duty effective today in the United States.

Sugars produced in the insular possessions, Porto Rico and the Philippine islands, are admitted free of duty.

In 1898, the Hawaiian islands, through annexation, became a part of the United States, consequently no duty is assessed on sugar or any other Hawaiian product.

Every vessel coming into a port of the United States must be entered at the custom house, where a record is kept of the port whence she came and of what her cargo consists. If from a domestic port, she is permitted to discharge her cargo without delay; if from a foreign one, customs officials are immediately sent on board to watch the cargo as it is discharged and supervise the tallying, checking or weighing, according to the class of merchandise. Besides being weighed, sugar is carefully sampled and the percentage of sucrose ascertained by the polariscope, for the customs duty is based upon the purity of the sugar, all raws testing not above seventy-five degrees polarization paying .71 cent per pound and .026 cent per pound for each additional degree. This is equivalent to 1.256 cents per pound for ninety-six-degree sugar.

The people of the United States used 4,257,714 short tons of sugar in the year 1915. It was nearly all produced within the United States or in countries enjoying tariff concessions, as follows:

SHORT TONS
Hawaiian islands (Cane) 570,375, U. S. territory.
Louisiana (Cane) 251,740, U. S. territory.
Domestic production (Beet) 861,568, U. S. territory.
” ” (Maple) 17,248, U. S. territory.
Porto Rico (Cane) 336,347, insular possession.
Philippine islands (Cane) 134,626, insular possession.
Cuba (Cane) 2,062,594, reciprocity treaty.
Foreign sugar (Cane) 23,216, full duty-paying.
4,257,714

Aside from the small amount of full-duty-paying foreign sugar imported, the only sugar in the above list that paid duty came from Cuba. It is evident, therefore, that under ordinary conditions an increase in the crops of any of the places mentioned would result in a surplus of sugar in the American market. In 1916, with the beet production of Continental Europe locked up by the war, Cuba’s increased output has been absorbed by Great Britain, France, Italy and Greece.

Steamers from Hawaiian ports, after arriving and entering at the custom house and passing quarantine and health officers, proceed immediately to refinery docks to discharge cargo.

REFINING OF RAW SUGAR

Cane-sugar refineries are always located in great seaport towns for the reason that, as practically all cane sugar is grown in the tropics, it must be transported by water to the world’s markets.

The refining operation is by no means as simple as may at first appear. It is essential that the finished product be almost chemically pure (99.8 per cent), and the greatest care must be exercised to obtain a perfectly white color, as well as a hard, lustrous grain.

The question naturally arises, why do not the planters of Hawaii, Cuba, Java and other raw-sugar-producing countries carry their process a few steps further and make a pure white sugar as the refiners do? This has been attempted many times, but has almost always been found impracticable, notwithstanding the fact that there is no mechanical or chemical reason why.

Among the arguments in favor of a mainland seaport site, the following may be mentioned:

1. The producing centers are generally far distant from consuming markets. Refineries located in the tropics would be under unusual expense for transporting and selling the refined article.

2. A refinery in the tropics would be out of direct and prompt touch with the individual requirements of the buyers.

3. Refined sugar should be moved and sold as soon as possible after its manufacture, so there follows the necessity for adequate dock and rail facilities as means of quick communication with the market.

4. An abundant supply of pure, soft water for refining purposes, and salt or fresh water for condensing, as well as fuel for the generating of steam, must be readily available. Another most important requisite is skilled labor, which is more easily obtained in populous seaport cities than in the small, isolated towns of the tropics.

5. There are many commodities used in the refining of sugar and in packing it for shipment that can be purchased more advantageously, both as regards price and promptness of delivery, in the great commercial ports than in the sugar-growing districts. Among these are bone-char, lime, acids, cotton filter-bags, burlap, cotton cloth, boxes, barrels, cartons, iron, steel and machinery of all kinds.

6. A sugar refinery is operated the entire twelve months of the year, while a raw-sugar mill must of necessity take care of the crop of cane in about eight months. To refine sugar where it is grown would require refining machinery capable of handling the entire output in the eight-month period, and during the remaining four months the plant would remain idle. This would mean a larger investment proportionately than that made in a refinery in a consuming center, running steadily the year round.