The STORY of CUBAN SUGAR ^SSS " Stand" of Mature Carte The '^rOKY of CUBAN SUGAR PHILIP KEEP REYNOLDS Published by United Fruit Company BOSTON, MASSACHUSETTS 1924 Cori KicHi' I 924 liV UnITEIJ 1<'rMT CoMI'ANV ;ClA7h2»«ls MAR ^/I924 Introductory ^A(ote 7 HIS pamphlet has been compiled in response to numerous requests for general intormation regarding the Cuban sugar industry. As nearly all Cuban raw sugar is shipped to refineries, principally those on the Atlantic seaboard of the United States, there would be a decided lack in any account that did not include some description ot refining operations. The subject, therefore, is treated under three main heads: I "The Plantation in Cuba"; II "The Factory or 'Central' in Cuba"; III "The Refinery in the United States." The description ot the industry is based mainly on the operations of the United Fruit Company and those of its subsidiary, the Revere Sugar Refinery. It is not generally realized that the United Fruit Company, most widely known for its banana activities and steamship transportation, is the best example in the world today of a self-contained sugar enterprise. It owns in Cuba some 89,000 acres of growing cane, as well as undeveloped land suitable for additional planting; 340 miles of railway; and at the seaboard in Oriente Province two large modern sugar mills. Central Boston and Central Preston, each having a rated daily average capacity for grinding 7,000 tons of cane. With the exception of the grinding units, these two factories are electrically operated throughout and represent a combined maximum annual output of 1,400,000 bags (200,000 tons) of raw sugar. Adjacent to Central Preston the Company has recently erected a distillery, complete in every detail, for converting the final molasses of the sugar mill into alcohol-ether motor fuel, to be used in internal-combustion engines in- stead of gasoline. In some respects, this fuel is superior to gasoline. The sugar fleet of the United Fruit Company comprises four modern oil-burning steamships. Each of these vessels has a carrying capacity of 24,000 bags, is equipped with a 20-ton lift for handling heavy cargo, has accommodations for six passengers and can develop a 10J2 knot speed. This fleet transports the Company's raw sugar directly to the Revere Refinery, situated on deep water in the Charlestown district ot Boston, and on the return trip to Cuba carries the necessary suppHes for the two Sugar Divisions of the Company. The Revere plant, which has a daily refined-sugar output of 4,000 barrels, embodies the most up-to-date construction, the latest mechanical improvements and the highest engineering efficiency in sugar-refining opera- tion. It has direct rail connections whereby its product, of unexcelled quality, is distributed throughout the New England states and elsewhere. It also owns and operates a modern fireproof cooperage plant which has a daily output of 5,000 barrels and 4,500 wooden cases. In the compilation of this work, the Author has purposely av^oided statis- tics and, wherever possible, technical language. Throughout he has en- deavored to treat the subject broadly, yet in sufficient detail to present an accurate picture of the processes which mark the progress of a stalk of sugar cane from the field, through the mill and the refinery, to its final state — re- fined sugar. The Author takes this ojijiortunity to express his appreciation of the assistance received in the jirejiaration of this article from the agricultural and the factorv staff's in Cuba as well as from the rcfinerv staflF at Boston. Qontents PART \~The Plantation in Cuba Page History ij The Plant 15 The MoDERiV Plantation 18 Preparation of the Land for Planting 19 Planting 21 Cultivation 25 Crops 25 Harvesting 28 Transporting the Cane 30 "Colono" Cane 32 Factors of Yield 33 PART \\ The Swsar Factory or ^'CentraF' in Cuba o Usual Method of Manufacture 3-7 Chemical Controi -y-j Factors of Efficiency 3-7 Delivery of the Cane 39 Extraction of the Juice ■. . 39 Clarification 44 Evaporation, and Formation of the Crystals 48 Separation of the Crystals from the Molasses . 51 Bagging and Storing 51 Marketing 52 "Blackstrap" or Final Molasses 52 PART III The Refinery in the United States Basis of Purchase ^5 Import Duty <;j Discharging the Sugar Cargo j6 Usual Method of Refining 59 Melt House 60 Filter House 63 Pan House 65 Finishing House 66 Cooperage 67 Marketing 68 Delivery 68 Disposal of Empty Raw-Sugar Bags 68 Conclusion 69 Bibliography 71 Illustrations "Stand" of Mature Cane Krontispiece PAin^ \ — T/ie Pla7itation in Cuba Page BrRMXG Underbrish ox New Land 15 Cane Cut as "Seed" for Pi.antinc; 16 Making Hill Readv ior "Seed" 16 Slipping "Seed" into CiRorxD 16 Cane Four Months Old 18 Cane One Year Old — Sixteen Stalks from One "Seed" 19 Plowing with Oxen (2 \'iews) 20 S'lEAM Plow — "Kxifinc;" the Soil --.23 'I'rac'for Pi.owinc; 22 Weeding by Means of Hoes 24 Cutting Cane 24 A I'l'iuRE Cane-Ci'i'I'er 25 Hafiling Cane in Old-Stvle Cart 26 Hal'ling Cane in New-Style Cart (Cateri-illar) 26 Hauling Cane with Gasoline Tractor 26 Transferring Caxe from Carts 10 Cars — Sin i-l. eg Hoist 28 Transferring Cane frclm Carts to Cars — \\\.\ H(hst 28 Herd of Steers Rrf:i) on Plantation 29 'l\ PE OF Pl.ANTAI ION LoCOMOTIXE BaLDWIN jO Train of Loaded Caxe Cars 3^ .Administration Hfildixg 32 Hospital 33 I<'arm Overseer's IIouse 34 Lakorers' Barracks I<',rected r>Y CoMi' \XY 34 Native Huts 34 PART II I'/ic Sinrcu- Mill or'-'Ccfitrur^ i/i Cuba Cenfral Presfox 36 Cenfrai. Boston 3^ Lfs Clubhooe, Church and Cottages for Mf.ch\nics 38 Switching Caxe (. ars af the Mill Yard 40 L XI.OADlXf, "SiDE-DuMI'" CaXE CaR 4I IllustriU'ioris (Continued) Page Cane Bein'g Co.weved to the Crushers axd the First "iMii.l" 42 Cane Mat in Foreground Leaving Second Crusher 43 Tandem with Double Crushers and Three "Mills" 44 Four-Unit Dorr Clarifiers 46 Two Sugar Ships at Presion Wharf 48 PART \\\-'The Refinery in the United States Revere Sijgar Refinery 54 Unloading Raw Sugar at Refinery 56 Sampling Raw Sugar at Refinery 56 Weighing Raw Sugar on U. S. Cjo\er\mfnt Scales 57 Raw Sugar in the Warehouse 58 Power Plant 59 The Laboratory 60 Vacuum Pans — Where the Sugar Crystals are I'"ormed 61 "Purging" THE Sugar IN the Centrifugals 61 The T'lNisHED Product — Packed in Barrels, Bags and Carions 62,63 Loading Truck with Sugar ■ 64 Battery of Trucks Loaded with Sugar 65 Cooperage Plant— Exterior AND Lnterior 66,67 Diagram of Refinery Process (Condensed Flow-Sheet) 70 Part I The T^lantation in Quha The Story k V of C i' i? a n S u ci a r ^- -hO' ■.,; t^lts Hhj^miii^' '^ii£X± Burning Underbrush on Nck- Land 4,000,000 tons of raw sugar in 191Q. It is today the largest single source ot the world's supply of cane sugar and for this reason is often termed the "World's Sugar Bowl." In the Island at the present time there are nearly 200 mills, many of which are of the most modern type and do exceedingly efficient work. It is very interesting to trace the introduction ot sugar into the civilized world. At first, it was regarded as a curiosity and was presented to royalty; then it came into use as a medicine; later, it became a luxury; and now it is a necessity. It is only within the past thirty years that the food value, or energy-producing power, ot sugar has been appreciated.* "The T^layit C^UGJR cane is a member of the grass family, known i \ botanically as Sacchaj'nm officinaritm. It grows in all tropical and sub-tropical countries and, although attaining its best development in the lower levels, it can be cultivated on elevations of 4,000 feet. A hot, moist climate with copious rains previous to planting and in the growing season, and cool, dry weather during the ripening period, are essential to the production of sugar cane to the best advantage. An annual rainfall of about sixtv inches is considered desirable. 'Food Products from Afar," by C. H. S. and H. S. Bailey. [Page I 5 1 The Story of Cuban Sugar -»?- -5«. n. The sugar-cane plant consists of roots, stalks, leaves and flowers. The roots, slender and numerous, grow lateralK' rather than downward, and vary in length from eight- een to thirt\-si\ inches. From the original rootstock, several shoots develop, forming tinalh' a hill or stool. Extending the entire length of the cane stalk, joints or "nodes" occur at distances of from four to eight inches i^i-:-;:'.: Ki'-Jti::*: -a^'-i^i.-: L'pPER \'iE\v: Mtikiii\; liill Rcuiiy Jfir " Sicd Centre View: (unic Cut as " Seed" for Phuiting apart, five inches being the average interva in a good growing season. Kach section be- tween these joints is called an "internode." The top section of the cane, termed "cogollo," contains but little sucroseand is unfit for sugar making.* From each node grows a single leaf, which usually falls from the stalk as the cane * Sucrose is the chemical term for pure cane suaar. [I'age i6] nppnig " Seed" niiu The Story of Cuban S i' g a r matures. At the top of the cane arises a cluster ot long ribbon-like leaves, from the centre of which springs a slemler stem bearing the flowers; these torm a large tassel of a light reddish-gray color. Along the stalk, running lengthwise, are fibrous strands serving as chan- nels to conduct the water and the plant food from the roots to the leaves. The preliminary development of the sucrose in the plant takes place in the leaves, where, through the action of sunlight, carbohydrates are formed. This partially elaborated material then passes down into the stalk and is gradually converted into sucrose. The height attained by sugar cane varies considerably, according to the richness of the soil, the rainfall during the growing season, the amount of cultivation received, and the number of crops gathered from the same rootstock, or stool. A period of drought or of heavy rains leaves its imprint unmistakably upon those sections of the cane that are in process of forma- tion. Drought causes them to remain short and stunted; heavy rains make them grow long and rank. Fully matured cane in Cuba, grown under normal conditions, stands in the fields at an average height of from seven to twelve feet, although it sometimes grows as high as twenty feet. A field of young sugar cane resembles a field of corn; later, when the cane is full)' grown and the leaves have attained their normal size, this resemblance is much less marked. There are a great many varieties of sugar cane, but that almost univer- sally found in Cuba is the Crystalina, constituting more than ninety per cent of all the cane grown in the Island.* Sugar cane will grow in a great variety of soils. The most suitable is a clay loam, which, while retaining moisture, remains sufficiently open to permit of proper aeration and drainage. Potash, phosphoric acid, nitrogen and lime are the principal soil elements required. * 1 11 his hook," Cane Suaar, " Noel Deerr gives some tliirty pages to a discussion of cane varieties. Classi- fications have been made according to the colorof the stalk, shape of eye,colorot pith and other physi- cal characteristics, as well as according to the geographical origin of the varieties. In all these methods the line of demarcation is not always distinct, particularly in the case of canes produced by breeding. The original cane brought to the West Indies was of the variety since known as Creole. Later, other varieties, known as Otaheite and Batavian, were introduced and named for the islands of their origin. .\ Batavian cane known as Crystalina has been so largely developed that it is now the principal varietv in Cuba, and produces most of the world's cane sugar. It has been found that desirable qualities in cane can be developed by cross-breeding. The experi- ment stations in this manner have developed hundreds of seedlings, which they have designated by letters and numbers rather than by name. This development has been accompanied by a systematic study of characteristics, the object being the production of a cane which will grow well, which will be resistant to disease and drought and which, when brought to the mill, can be readily worked to produce a high yield of sugar. So far as Cuba is concerned, seedlings have not been developed to a point where thev are a commercial factor. [Page 17) 1^ H E S r u R V of C r B A N 8 I' G A R <*:r- 77;c -JM'oc/er/j T'la?itatioji -M^ inv( -5o. '//£ number and the magnitude ot the operations involved in preparing and equipping a large and efficient sugar plantation in Cuba are not usually comprehended by any one whose basis ot comparison may be general farming operations in the United States. \\ ithina tewyears' time a tropi- cal wiKlerness is transformed into a cultivated tract, with ample accommodations tor the housing and medical care of the army of laborers and other em- \, )iloyces. In additicjii, transpor- tation facilities on a large scale arc jiroxitletl. The land is first thorough- 1\' examined b)- experts who de- citle regarding its suitability for the culti\ation of cane. When selected, the lanil is surveyed and IS laid out in sections con- duci\e to the convenient ap- poi^t ion merit and efficient handling of the work to be done later, aiul with a \-iew to keep- ing )iroper records of all jiroiUic- tion ami other costs pertaining to each section. These prehminaries are fol- lowed by the work of clearing the land of trojiical growth, the digging of main ilrainage ditches and the actual plant- ing. Then, too, the sugar mill and the emplo\-ees' houses are erected; railroads are constructed; and food- stuffs and merchandise are made available at moderate cost. Likewise, hospital treatment is furnished in case of sickness or accident and the general sanitarv condition of the jilantation is maintained; in short, all means of general and emergency care of the personnel are atlequately established. [Page I S 1 Ciuie I'oi'.r Mouths Old T H E Story of Cub a n S u (; a r -05- '■'Preparation of Y'^ ^'^*^ preparation of virgin land for planting, the ,/ p Jr.. I trees and underbrush are first cut down. All good, the 1 a?ia [Of § . , . , , 1 r 1 -i r ,V. -\ -^ hard timber is taken out and saved tor Iniilding i la?ltlflg purposes, and a certain portion of the other wood is cut up and delivered' to the mill for fuel. The remaining timber and brush, which can- not be utilized in any way, are allowed to dry out and are then burned; whatever part may resist the first burning is gath- ered up in piles and burned again, until the land is gen- erally cleared. The utmost pre- caution is taken to prevent burning cinders, carried by the wind, from setting fire to standing cane. The ground, al- though containing roots antl some stumps, is now ready for planting. Accidental fires, due to sparks from locomotives and to other causes, constitute the most serious menace to grow- ing cane. To minimize this risk, fire lines are established, with an average width ot twenty yards. In many instances these fire lines are planted with sweet potatoes and other green veg- etables, which not only furnish food for the laborers, but also in themselves provide more or less protection against fire. The preparation ot the land for replanting is effected by means of steam plowing, tractor plowing or bull plowing, the fields usually being first burned over. The expense attached to the steam-plow method restricts its use to large areas, of one hundred rosas (177 acres) or over, but this Cane One Year 0/J — Sixteen Stalks Jro»i One "'Seed" The Story of C r b a n Sugar -o$- -5«. plow, if properly handletl, is very efficietU. Tractors are usetl to adxantage in small areas, but it delays are to be avoided, all logs and stumps must first be removed. Bull plows can be used on small areas with two or more yoke of bulls or oxen to a plcjw. After the various plowing operations, harrows are used further to puh'erize the surface of the soil. Ploiviuz 'ii'ilh (Jxcn [Page 2 o 1 T HE Story of C u b a n S v g a r ^ -_^ . ^ ^-^iV T'laJltinor I HE methods ot planting cane in Cuba vary con- -»- siderably, as do also the distances between the rows. Planting seven feet apart in the row, with a space of seven feet between rows, is the practice of the United Fruit Com- pany in new lands. The ground should receive not less than three inches of rainfall previous to planting. The usual seasons for planting cane are spring and tall. Except tor cross-breeding and selection work, the flower seeds are not used in planting. It is often difficult to obtain a good "stand" from them and, when they do germinate, the resulting plants are likely to vary in type to a considerable extent. This latter characteristic, however, is turned to good account in some experimental stations in the cross-breeding of de- sirable varieties and the selection ot the most promising plants to propagate in the regular manner. Superior varieties have been obtained in this way. Ordinary held propagation or planting is effected by means of cuttings from a stalk of mature cane, each cutting having usually three buds or "eyes," corresponding to the eye of the potato, located at the nodes. These cuttings are called "seed." The field of cane to be used for "seed" purposes is selected for its proper age, vigor of growth and general freedom from disease and insect pests.* It is most important that only healthv plants be used. The best seed for planting consists of cuttings from plant cane not over twelve months old. The cane selected is cut down, and in the same field it is prepared for use by being cut into sections of not less than two joints — preferably three. The end of the section cut should be about one inch, on each end, away from the joint or " eye." Any cuttings which have poor or broken eyes, or which show evidences of borer injury or disease, are rejected. In the cutting of a stalk of cane for seed, the upper portions below the "cogollo" are usually considered superior, while the lowest section, par- ticularly if it shows much rooting, is generally rejected. In the transporta- tion of the selected seeci to the field where it is to be planted, great care is necessary to avoid injury to the "eyes" from handling or from exposure to the sun. The seed should be planted not later than three days after cutting. * Deerr devotes thirty-six pages to the subject of diseases and pests of the cane, which are many, and which are liable to attack the roots, stalk and leaves. Among the diseases may be mentioned the Mosaic or mottling disease, the rind disease, the red rot of the stalk and the "pineapple" disease. Of the insect pests, the moth stalk-borer is conspicuous because of the holes it bores in the stalk. The damage it causes, while not very serious in itself, induces fungous infection and subsequent deterioration of the sugar content. Frequently, caterpillars cause considerable damage by eating the leaves of young cane. [ P .T g e 2 I ] The S t o k V of Cuban Sugar .05- -5«. Steam Ploiv (laki)i'^ on ivn/t'r) B\ means oj a steel cable the ploiv or k>iijcr is draivu hack and forth Tractor Ploivni" Pa ^- Thk Story of Cuban Sugar -So- " Knifing" the Soil between these two powerful engines stationed at opposite ends oj the field In the planting ot new land, the work must he done with a j-iick mattox or a sharply pointed stick, hecause ot the stumps and roots that remain even after the usual burning. The outer edge ot the field is measured off with a tape line tor planting, and stakes are set at proper distances as guides. A check wire is used in the lining and in the distributing of the seed. In the planting of the cane, a stick is thrust in a slanting direction into the ground to make a hole, into which one or two pieces of cane are inserted, generally with the upper end not more than two inches under the ground. The earth is then packed tightly around the seed by pressing with the foot. In the replanting of a cultivated field, alight plow is used to trace the fur- rows in which the cane is to be planted. These furrows, or rows, are usually six feet apart, instead of seven as in the case of the planting of new land, and the cane cuttings ("seed") are generally placed in the row six feet apart. The proper interval for planting varies according to the soil, so that throughout Cuba are found such variations as cuttings end to entl, every twelve or twenty inches apart, two rows of cuttings in a furrow — and many other different practices. The cuttings are laid in the furrow by hand; then a light plow is run alongside the furrow, and the earth is turned over to cover the cane from four to six inches deep. [Page 2 3 I The Story of Cuban Sugar •og- -.V U'ceding In Menus oj llocs Ct(tti>ig Cane [Page 2 . The S t o k ^' of Cuban S u g a r -05= -5«^ Cultivation T'F the ground is damp and in good condition, the / cane may be expected to show itself above the sur- face about two weeks after planting. Weeds, how- ever, soon make their appearance, and the work ot destroying them should not be delayed. The operation of weeding must be repeated as often as necessary until the cane leaves have grown over so that they completely shade the ground and prevent the sun from pene- trating through to the soil. In new lands this cul- \J' tivating is usually done by means of hoes. ?^| In the case of replanted fields, after they have % ," been cleaned by hand for the first time, the weeds are destroyed by running a cultivator, a light plow or a disc harrow between the rows of cane. Mules, tractors and oxen are usetl in this work. Crops .1 Future Ccuic-Citttcr 'HE first crop, calleci " plant cane," usually takes from twelve to fifteen months to mature. Spring cane, however, planted in May, is sometimes cut the following April, or eleven months after planting. After plant cane is harvested, new shoots develop from the original rootstock, and form what is called the second crop, or "first ratoons." These shoots may be cut after about twelve months' growth, and the operation may be re- peated a year later, given the right kind of growing weather. However, if enough cane is available for the mill so that the ratoons may be allowed from fourteen to eighteen months of growth, they will give a much better sucrose yield. The question of maturity, as regards each particular field, is something to be ccjnsidered individually by those in charge of cutting; no set rule can be given to indicate definitely the exact month in which canes should be harvested. Close observation of maturity, chemical analysis of average samples, amount of cane available for the crop, possibility of pro- viding "stand over" cane for beginning the next crop, — all these are factors that enter into the final decision as to harvesting. Leaving uncut cane too long in the field tends to start a series of new shoots, called "suckers," which are offspring of the parent plant, and which sometimes grow to the size of the parent plant itself, if harvesting is delayed too long. While these well-developed suckers produce tonnage, their sugar [Page 2 5] T H E S T O R Y of C U 1! A N 6 l G A R ^= -5«. mJ^. ^IvJifl^ ti^ \ llaidbi'^ C.auc ai Xi-iv-S/y/t' Cuirt yCatcrpillar) content is \'cry low. Further, there is a hea\ y accumulation of (lead leaves from over-ma- tured cane which increases the difficulty of har\esting. \\ hen cane becomes too old, it dries upantl the sucrose tends to be- come uuerted.* . .I'^^hi IxsKRT: Hdiiliiix Cinic in ()!(l-Stylc Cart Lower \'iE\v: IIaiilin\( Cintc n-ith Gasoline Tractor * Inversion ot sucrose is the changing of sucrose into glucose through processes of fermentation. [Pace 2 6 1 The Story of Cuban S i' c; a r •og ^ -^ .V When the cane is \ery young, its sucrose content is extremely low, being utilized in meeting the needs ot the growing plant. When cane ot these two extremes is harvested, the yield in sugar at the mill is less than would have been the case had such cane been harvested at the right time, and the opera- tion means smaller financial returns. The number of successive "ratoon" crops depends upon the quality of the soil, varying from six to eight on lands ot medium quality to considerably more on the newer lands. Virgin lands, from which the forests have been cut, produce the heaviest cane, although it is not usually as rich in sucrose as that produced on the old lands. In Cuba, a yield of from i^^^ to 50 tons ot cane per acre can be obtained from virgin lands, and sometimes even more, whereas the average yield for the Island probably does not exceed 18 to 20 tons per acre. When the ratoon crops become so poor that a reasonable profit cannot be obtained from continuing their cultivation, the land is either devoted to other crops, temporarily or permanently, or immediately or subsequently replanted in cane, according to the soil constituents and other factors. As cane lands become old and the yields decrease, the question ot ter- tilizers and their comparative values torces itselt upon the planter's attention. While many commercial fertilizers are on the market, Cuba, particularly the section comprising the Provinces ot Oriente and Camaguey, has not as yet developed the practice of fertilization to any considerable extent. It is much behind other countries in this respect. Because of an abundance of available virgin lands, it has heretofore been the practice, especially in these two provinces, to make use of new lands rather than to replant, cultivate and fertilize exhausted areas. Since these woodlands are now scarce, cul- tivation and fertilization must become important factors if the present Cuban sugar production is to be maintained. At the beginning and the close ot the crop season, the sugar content of the cane is usually the lowest. It is always the endeavor to grind the cane during its period ot maximum sugar content, although, where large cane areas are involved, it is sometimes necessary to begin grinding earlier, and continue later, than the sucrose content would seem to warrant. In the western and middle parts of the Island, the crop season generally starts the latter part of November or early in December and plantations in these sections finish their grinding — at the very latest — by the first of June, as the rainy season usually starts about the middle of May. In the eastern section ot the Island, how- ever, grinding usually begins the latter part of December or early in January [Page 27] The Story of C i' b a n Sugar -05- -5«. ^jj^ TrtDisJiiTiHi:^ Cane Jroui Carts to Cars — Stlf-Lci Hoist and is continufd until July -in the case ot a tew mills, until September or October. Weather conditions in Cuba, which vary consitlerably from year to year, as well as in different parts ot the Island in a single year, affect the length ot the grinding season. Hcirvesthig r 7y^///^.V the I/m/ cane is ready tor harvesting, it is cut by hand at the base of the stalk, t^ush with the ground, a long knite or cleaver be- ing used.* The leaves and the green top are then severed ami the stalk is cut into lengths ot trom three to four feet and thrown into piles. f * Cane is cut at the ground level tor the rea- son that the lower portion ot the stalk is rich in sucrose, and further, it the end ot the stalk were left above ground, anti there should he anv " eyes " in it, thev would lie likely t( 1 sprout and Trail sfcrrhi;:; Cane front Carls to Cars -/ lUi Hunt impair the fertility of the stool. t The top is removed at a jioint between the end of the solid cane and the beginning of the soft, Crowina: portion. Inspection ot any cane stalk will reatiilv reveal, even to the uninitiated, where the solul cane ends. ' iiSas^f^ (Page 28] The Stor\- of Cuban Sucjar -<»§- '5^ Herd oj Steers Bred on Plantation The leaves and the green tops are left in the field. They conserve the moisture in the ground, and form an excellent mulch that aids in preventing the growth of weeds and grass until such time as the new cane afi^ords shade for the ground. This mulch, when it decays, has some value as fertilizer. The green tops also afford an excellent fodder for the cattle and constitute their principal food during the crop season. It is essential to economical operation that there be proper supervision of the cane cutters to ensure proper cutting and loading of the cane and to prevent the loading of the top portion, trash and leaves. Otherwise, the fac- tcjry pays for this trash — which has no sugar value — and carries the addi- tional and superfluous burden of eliminating these impurities in the manu- facturing process. The operation of harvesting the cane, as well as its cultivation, is usually handled on a contract basis, the contractors having direct charge ot the laborers, and their lodgings, food and wages. The mill settles directly with these contractors, but at all times exercises close supervision over their work and the treatment accorded their men. The mill actively assists the contrac- tors in obtaining their supply of laborers, and erects the lodgings, called "barracones," for the men. It is the general practice tor the mills to supply some of the bulls and carts used in hauling the cane. In the case of the United Fruit Company, practically all of the carts and more than halt of the live stock used for this purpose are furnished by the company. [Page 29] «05- T H E Story of Cuban Sugar -5«. p*^.. 7"_v/i(' «/ PlaiUatifiu I .(icoiiiDlivt — Baldicin The sramlard of weight on which payment is niaiie for cuttmg and loading the cane is the arrohc, or 2> Spanish pounds. (A Spanish pound is equi\alent to 1.014,^ Knghsh pounds.) Lahorers are paid hy the contractor usually from 7s cents to 5 1.00 per 100 arrohas for cuttmg and loading into carts. The cost of the haul to the railroatl siding is figured on the basis of the distance, and ranges from 25 to 50 cents per 100 arrohas, tor labor only; when the cartmen supply their own carts and the cattle that haul them, they are usualh' paid double rates. Cane-cutting iinoKes the most serious labor ]iroblem that confronts the sugar planter in Cviba. In the first jihice, to ojierate the mill economically it is necessar\' to furnish it with sufficient cane to keep it running night and day throughout the croji season. In the second place, cane-cutting is a laborious hand process, and the supply of labor is inadequate for the Island's needs. It is to be noted that thus far no mechanical cane-cutting device has proved successful in Cuba. Tr-ansport'uig the Qane I HE methods used for delivering cane from the -Afield to the factory are twofold: animal and me- chanical. The piles of cut cane are loaded into two- wheeled bull carts and hauled to the nearest railroad siding. Here the cane is weighed and then transferreti, generally by means of field cranes, sometimes by hand, to railroad cars of special design. The weighing of the cane in the [Page 3 o 1 The Story of Cuban S u c; a k t^- -5©. field is effected by means ot either a platform or an o\-erheat) scale. When the former is used, the cart is weighed with its loatl ot cane, the tare, or weight of the empty cart, being dedvicteil. When an overhead scale is used, the cane alone is weighed. The contractor pa\s his men on the basis of weights thus obtained, while he in turn is paid on the basis ot the weights cietermined at the mill. On the United Fruit Com- pany's plantations the ckniisy high wheels of the cane carts have been replaced with cat- erpillar treads, which make it possible tor tewer animals not ^"'-■i ' • only to haul greater loads ot cane, but to haul them under all kinds ot road and weather conditions. These caterpillar treads, moreover, improve the condition ot the roads. On the Company's plantations, haul- ing experiments have recenth- been made with tractors, antl it is not unlikely that within the next tew years tractors will g r a d u a 1 1 y r e p 1 a c e b u 1 1 s and oxen to a considerable extent in this phase ot the work. When each car is loaded, a tag is affixed giving the data required, such as the name ot the farm, the contractor, the siding, the date when loadeii and the car number. The farm overseer makes a daily estimate of the number of empty cars required for his district, together with the distribution by sidings, for the ensuing twenty-four hours. A proper distribution of "empties" is es- sential for purposes of maximum economy; it is particularly important when the mill is running to capacity that every available empty car be utilized in keeping the factory properly supplied with cane day and night. As the 1 P n g e 31] Traill of Loaded Caiic Cars The S t o r -i' of C r i? a x Sugar -o^- -^ . -tdmin'tstratiou Building railroad is efficient only when each car carries its capacity loadot cane, it is one of the duties of the farm overseer to see that every car is loaded Kill. The cane is delivered to the mill in long trains, each car containing from ten to thirty tons of cane, according to the gauge ot the railroad. a Qolo?io" Qane I T is the policy of most of the centrals in Cuba to purchase by contract a considerable portion ot their cane from adjacent planters, called "colonos," who grow the cane on their own or leased land, or on land belonging to the cen- tral.* This practice on the part of the centrals encourages the planting of cane by individuals within a convenient radius ot the tactory. As a rule, the centrals advance the necessary w^orking capital to the colonos, and the settle- ments tor cane delivered by them are applied against such loans. The usual form ot contract stipulates that the colono must supply cane of proper age and condition, without tops or suckers and not fermented, and that he shall receive therefor a certain percentage or unit of sugar, based on the weight of his cane as determined by the factory scales, or its cash equivalent. • The cane farms operated bv these planters are called "colonias." [Page :,z\ The Story of Cuban Sugar ■^ — g» rr FP ri" ^^^^^TB! r-lT?i?fi^Tif^ Hospital This sugar unit varies from 5 to 8 per cent, according to conditions and customs prevailing in different parts oi the Island. For example, if a colono has a contract stipulating 5 per cent, he receives, for every 100 arrobas (2,500 pounds) of cane which he delivers, 5 arrobas (125 pounds) of 96° test raw sugar, or its equivalent in cash. The latter usually represents the average of the market prices of raw sugar, as reported officially from Havana, during the week or fortnight within which the cane is delivered by the colono to the mill. It is the general practice to liquidate the colono accounts in cash, but some of the Cuban-owned mills pay the colonos in actual sugar. It is interesting to note that while about 80 per cent of the cane produced in the Island is raised by colonos, the greater portion of the cane ground at the two mills of the United Fruit Company (Centrals Boston and Preston) is company-grown or "administration" cane. FacfOf'S of t HE tonnage yield of cane per acre is the figure Yield closely followed by the agricultural management, while the raw-sugar yield per ton of cane ground is the controlling factor in the case of the sugar mill. Thus the basic figure, when available, for the sugar company's executives is the number of pounds [ P a g e 3 3 I The Story of Cuban S r c; a r -05- -5«. I arm Occrscir' s llonsi ot raw sugar produced per acre ot cane. This latter tactur, howexer, is not eiii- ployeci extensixeU in Cuba, because ot the "colono" svstem, and because the cane is usually deii\'ered to the mill smiultaneously from so man\' different points, that it is ditficidt, it not impracticable, to keej'' an accurate recori.1 ot the commercial sugar yield per acre. This record, h()\ve\'er, is available in Hawaii and is in tjeneral use there. Lj>**ii,;^ La(/u)i)\\' Han ill ks Liitttii i/\ Couijuuiy 11: [Page 34] Part II The Sugar Factory or '^QeutraV* in Quha Mt^- T H E Story of Cuban Sugar -5«. ri / - ' '-Si [ 1' a g e 36] The Story of Cuban Sugar Part II 'The Sugar Factory or ^^Qe^itra/^^ in Qiba The final product of a central is raw sugar of a light brown color and of approximately 96 degrees polarization, or sugar 96 per cent pure. The term polarization, as employed in the sugar industry, indicates the method of de- termining the percentage of sucrose by means of an instrument known as the polariscope. . ■ Usual zJACcthod t HE usual method of manufacturing raw sugar from ofzy^afiufacture cane may be considered under four general heads: Extraction ot the Juice Clarification Evaporation, and Formation ot the Crystals Separation ot the Crystals from the Molasses r*hetnical T^ ^^e manufacture ot raw sugar there are some r^07ltrol I '-I'l'ivoidable losses ot the original sucrose in the cane, principally in the "bagasse," or crushed cane; in the filter-press cake; and in the final molasses. To reduce these losses to a minimum, strict chemical control of the factory is essential. This involves keeping an exact account ot the sucrose entering the factory in the form of crude material — cane; and ot the sucrose leaving the central in the form ot finished product — raw sugar, as well as ot the losses ot sucrose in the bagasse, the filter press cake and the final molasses. This work requires that all weights and measurements be accurately taken and that the material in process at the various stations throughout the factory be properly sampled and carefully analyzed. A compilation of the various data constitutes what is known as the daily and the weekly report. FactOfS of i ERTAIN basic factors are of vital interest to the Efhciencv VV "''^'■'^ge'''''£"t in the proper checking of plant operation. These are: first, the milling or grinding efficiency, indicated either by the percentage of juice extracted, based on [Page 37] The SroR-i- of Cuban Sugar •>•- -5«. Ct'iilral Boston total juice in cane, or by the percentage of sucrose in the extracted juice, based on total sucrose in cane; second, hoiling-house efficiency, indicated by the percentage ot sucrose, in the form ot raw sugar, recovereii from sucrose in extracted juice; and third, general factory efficiency, determined by the percentage of sucrose in raw sugar produced, based on total sucrose in the cane entering the central. The average results obtainetl by the modern centrals in Cuba show a grinding efficiency of from 91 to 9> per cent; a boiling-house efficiency of from 92 to 97 per cent; and a general factory efficiency of from 85 to 90 per cent. .iitmiidl MMWiawnriri — -—•^-^ 1 -I'h I/s CIi(IjIwhsc\ Chunk diid Cottages jor Mcchivius [ P a g e 3 8 1 The Story of C r u a n Sugar T)elivery of the /^\^ arrival at the mill yard, or "hatey," the cars of ra?lC f J "-"^""^ ^"^"^ '^'"'-^ weighed indi\idually. The net weight of the cane in each car is ascertained by deducting the tare, i.e., the weight ot the empty car. It is on this basis that the contrac- tor and the "colono" are paid for company and private cane, respectivelv. After being weighed, the cars are placed alongside a conveyor which feeds the factory with cane. Next, each car in turn is shunted to a dumping platform, or tipping table, where it is securely held by clamps. One side of the car is then opened, and the platform, together with the car, is tilted towards a dump pit into which the cane falls by gravity. The floor of this pit is the initial unit of the conveyor which gradually carries the cane upward to the grinding or milling plant, located on the ground floor ot the factory, where the juice is extracted. The conveyor, or cane elevator, is driven independently of the milling plant, a method which tends to insure uniformitv in the delivery of the cane. After the car is emptied, the tilting platform resumes its h(M-izontal position and the empty car is removed. The handling of cars from the scales to the tipping table and from there to the mill yard is usually effected by means of an electric or steam winch. Extraction of the ^ MHE milling plant in the smaller factories usually 'fuicc -^ consists of one " tandem, " comprising a "crusher" and three or more "mills." The larger plants are usually equipped with two or more tandems (paralleling each other), each comprising double crushers and three or more mills. In two or three of the most modern installations in Cidia, the tandem consists of triple crushers and five or six mills. Independent records are carefully kept of the work of each tandem.* A "crusher" consists of two rolls, placed one above the other, with interlocking or corrugated teeth, or with deep grooves in their surface. A "mill" is composed of three rolls, as contrasted with the two cylinders of a crusher, one roll being on top and the other two on the lower level. Their surface is annularly grooved to facilitate the grinding action and to enable the rolls better to grip the cane mat. Both the crusher and mill rolls are high-grade cast-iron shells shrunk on heavy steel shafts and, in the larger plants, are usually seven feet in length and about three feet in diameter. * The first cane mill was a tree stump, hollowed out to form a mortar. In this mortar, a log, acting as a pestle, was revolved by oxen. Then came stone mortars, then wooden rolls and then the hydraulically- operated metal rolls of the present day. [Page 39] The S t o r ■!.' of C u c a n S i" g a r ^- ■i5«. Switchinz Cane Cars at the Mill Yard Each crusher and mill unit is hca\il\- mounted on substantial bedplates and housings. The toji roll of the crusher antl of the mill units is controlled by a hydraulic ram which permits the roll to rise and tall or "Hoat" with the va- riations in the teed ot the cane. Practice \aries as to the hytlraulic pressure applied to these top rolls. In the more modern ]ilants, this pressure approx- imates about 250 tons on the crushers anci ranges from about 350 tons on the first mill to about 500 tons on the last mill unit. The tandem is driven by steam or electricity, through a train of double retluction gears, the shafts being directly connected to the top roll or each mill unit. The gears are so arranged that the speed of the rolls is grailualK- increased from the first to the last mill unit.* Upon entering the tactor\-, the cane falls evenly from the head of the con- veyor by grax'ity chute to the first crusher, ami then passes by gravity to the second crusher below. This preliminary grinding breaks down the hard struc- ture ot the cane, which is prepared for milling by being crushed, torn and * Central Boston milling plant comprises the foUowins;: two tandems, each consisting of two sets ot crushers and five sets of mills; also two tandems, each consisting of four sets of mills, the first set being grooved and functioning as crusliers. Central Preston milling plant has two tandems, each consisting of two sets of crushers and five sets of mills; also one tandem with two sets of crushers and three sets of mills. [Page 40] ^- T H E S T O R ■i' of C U BAN S U G A R -5«. Unloading "Side-Dump" Cane Car matted. Thelarger percentage of the juice is extracted in this initial operation. The mat of crushed cane is then carried by an apron or slat conveyor, called an "intermediate conveyor," to the first and succeeding mill units. A heavy curved metal plate, supported by a proportionately heavy bar, and placed between the two bottom rolls ot each unit, guides the cane, which first passes between the top roll and the front bottom roll, called the "cane roll," and then travels between the top roll and the back bottom roll, called the "bagasse" or "discharge" roll. The blanket of cane in like manner passes through all the mills, the rolls of each succeeding unit being set closer together than those ot the preceding. The function of the mills is to grind the cane more thoroughly than the crush- ers and to extract as much additional juice as possible. After passing through the last set of mills, the blanket or mass of crushed cane (bagasse) is mechanically conveyed to the furnaces, into which it falls by gravity, and is burned as fuel to generate steam. Any temporary excess of bagasse is mechanically diverted to storage, and is reclaimed by the same con- veyor system and returned to the furnaces as required. Since the fuel value of bagasse is inversely proportionate to its moisture content, it is important to obtain as dry bagasse as possible. In a modern plant the bagasse from the [Page 41] The Story of Cuban S r g a r ^- -5«- ('.(Die Hc'ufr Conveyed to the (Juslwrs and the First "Mill" last mill will usually contain from 2 to ; per cent ot sucrose, ami from 47 to 55 per cent of moisture. As a rule, after the crop is well untler way, little fuel other than hagasse is necessary, except where maceration (descrihed below) is practiced extensively. Crude oil or wood is used tor auxiliary fuel. The raw juice, which is turhid and yellowish or greyish-green as expressed from the mills, tails into Juice pans directly helow the tandem; thence over strainer plates or screens, which remo\e the toreign matter ami the fragments or particles ot cane fibre, to the gutters or troughs; whence it flows by gravity to the juice wells. 'I"he strained juice is then weighed or measured and pumped to the clarification department, onlinarily situateil at the top of the house. To obtain the maximum extraction ot sucrose, water (some factories using hot and others cold) is applied to the cane mass while it is passing through the tandem, usually in front of all the mills except the first set. This practice, called "maceration" (also "imbibition" or "saturation"), assists in washing out part of the remaining sucrose from the cells of the cane. The water used tor this purpose \aries from 10 to 25 per cent or more, figured on the basis ot weight ot cane. The extraction of sucrcjse is affected by the quantity ot maceration water used, which, in turn, may be limited either by the insufficient capacity of the evaporating plant to handle it or by the lack [ 1' a g e 4 : ] The Story of Cuban Sugar -o:'. ' - ^ ",/ / aliirijicrs Central Boston and CL-ntral Preston, hax'e recentU' installed Dorr Clarifiers to replace the defecators and settling tanks. These clarifiers, large cylindrical tanks, each di\itled into four compartments, continuously remo\'e the iminiri- ties from the strainetl raw juice, which has been previously limed and heated. The scums from the juice rise to the surface and are automatically skimmed oft ami dischargetl. The mud settles in each compartment and, by means of ir.echanically operated arms, is mo\ed to a central opening through which it drops to the bottom compartment. The mud is now of the consistency of porridge and is remcned by an especially designed type of pump, which delivers it in a uniftjrm, continuous flow to the filter presses. From each of the tour compartments the clear juice flows by gravity to a common o\erflow box, the discharge from each ccjmpartment being regu- lated by sleeves which permit the overflow level to be raised or lowered. This clear juice is sent to the evaporating department. [Page 46] The Story of Cuban Sugar ^ — .V At Central Preston, in conjunction with the Dorr Chirifiers, the Petree Process has also been installed.'" The principal object (jf this prcKX^ss is the elimination ot the filter-press station with its attendant sucrose losses and high cost ot operation and upkeep. Under this process the rich juice from the crushers anci the first mill is independently and separately clarified from the thinner juice resulting from the subsequent milling of the macerated cane. This practice constitutes what is termed "primary clarification" and "second- ary clarification." The juices are limed at the mills by means of a new type ot liming appa- ratus. This is operated from one of the mill rolls and thoroughly mixes the milk ot lime with the juices at an early point, whereby considerable inversion and fermentation are thus avoided. In the operation ot the Petree Process, the rich juice trom the crushers and the first mill is mixed with the juice trom the secondary clarifier. This mixture is heated and delivered to the primary clarifier, the clear overflow ot which goes to the evaporators. The mud from the primary clarifier is mixed with the juice coming from the second and the third mills. This mixture is heated and delivered to the secondary clarifier, which separates it into "secondary" clear juice and "secondary" mud. The former, as shown in the preceding paragraph, is mixed with the rich "primary" juice anti thus undergoes a turther clarifica- tion. The "secondary" mud is mixeci with the juice from the fourth and the fitth mills. This mixture is evenly distributed in a thin stream over the whole width of the bagasse coming from the first and the second mills. It is ot interest to note that the bagasse acts as a filtering medium, the solid particles ot the mud being enmeshed with the crushed fibres ot the cane. This en- trapped mud is carried to the furnaces as a part ot the bagasse, and con- stitutes a certain addition to the fuel. The ashes, which are remarkably tree from clinkers, are collected and used in the fields as tertiliz.er. The mud returned to the mills cannot get into the clear juice going to the evaporators, because any sediment passing through the bagasse goes only to the secondary clarifier, whence it is returned to the mills. With con- tinuous settling and withdrawal of mud trom the clarifiers, there is a steady flow to the mills; on an average, to each loo tons ot cane passing through the mills, there are returned 5 tons of mud. * The Petree Process is still in the experimental stage and has been installed at Central Preston on trial. [Page 47I The S t o r V of C r b a n 8 u g a r ^- -^ III.IM Tv:o Sugar Ships at Preston Wharj ^-vaporatiofl^cuul * MIIE clear rhin juice ohtaineil 1\\- clarification Por/Ilil t iofl of the -^ must now he reiluceil to the consistency ot a Crv ■/ //■ s\rup and it is sent, hy either yraxity or junnping, " to the supply tanks ot the evaporators. The exaporator is a series ot large closed \essels called "etlects, \w which the claritieil juice, under a partial \acuuni, is concentrated and its water content reduced from about 85 to about 40 per cent. 1^'our \essels are usually employed, the apparatus then being called a "ipiadruple effect." The sugar manufacturer, making use ot the principle that liquids boil in a vacuum at a lower temperature than m an open \essel subject to normal at- niositheric pressure, reduces the atmosjihenc ]iressure in each effect to a point below that of the precetling one, in order to secure the maximum ot economy in operation. The first \'essel is theretore heated by means ot steam, the second by the vapors evaporated trom the juice in the first \essel, the third by the vapors trom the second effect, and so on to the last effect. From the evaporators the thickened juice, called syrup or "meladura," now dark brown in color, is pumpeil to storage tanks on the pan floor to be boiled in the vacuum pans as required. These "pans" are closed vessels heated by steam and are somewhat similar m construction to the e\"aporator 1 1' a g <•• 4 S I T n E Story of C u b a n Sugar ^ - ^ — — 5^ effect. A portion of the syrup is admitted to the pan where the final hoiHng down takes phace. This is accomphshed under a vacuum ot trom 25 to 27 inches, maintained by means ot a steam or motor-driven vacuum pvimp and a large barometric condenser. When the syrup boils down to a certain density, generally 88 degrees Brix, the grains or crystals of sugar begin to form.* The principle ot sugar crystallization is embodied in the tact that water can hold only a given amount ot sucrose in solution. xAs the water is driven out of the cane juice, the latter finally reaches a stage where there is not enough water left to hold all the sugar dissolved. As evaporation proceeds, therefore, the sugar, deprived of its water, is compelled to pass out of solution into crystal form. The number and size of the crystals, and their proper growth as the syrup further evaporates, constitute a problem ot skillful manipulation ot the vacuum and involve the rate at which additional syrup or "first molasses" ox "second molasses" is drawn into the pan. This important work is under the control of well-trained men called "sugar boilers." The resultant prodvict ot the vacuum pan is a heavy mass ot crystals, dark brown in color, termed "massecuite."t It is not possible to boil all ot the syrup and molasses down to a crystal and at the same time separate the pure sucrose trom the impurities; therefore, enough moisture must be left in the massecuite to permit separa- tion of the crystals in the drying process. The impurities remain in the mother liquor and are carried off as molasses. In the process of manufacture the chief aim is to extract the greatest possible amount of sugar from the syrup. For this purpose various methods of boiling have been evolved, but the " three-massecuite " system, described on the following page, is the one mostwidelyused.t This involves the manufacture * The sugar industry uses floating spindles, called hydrometers, to indicate the amount of solids con- tained in a sugar solution. The scales enclosed in the stems of these instruments are graduated according to either the Brix or, the Baume system. Brix hydrometer, floated in a pure sugar solution, will indicate directly the percentage of sugar by weight. Any other substance present will increase the reading, so in an impure solution the Brix gives an approximation of the total solids. By dividing the percentage of pure sugar, as fount! by the polariscope, by the Brix reading, the purity of the material may be found. For this work, the Brix scale is used in the laboratory. The Baume scale, originally made to read percentages in a salt solution, has been revised so that now its reading is purely arbitrary. Its graduations are farther apart than a Brix scale of the same range, and therefore easier to read. This explains its continued use in the factory, t A complete operation, or cycle, of the vacuum pan is called a "strike" in both a central and a refin- ery, but in the latter it is also sometimes known as a "skip." { First, second and third massecuite are called A, B and C massecuite, respectively. [Page 49] The Story of C v r. an Si' c; a r of "first," "second" and "third" sugar. The first and second sugars are mixed and sold as raw sugar of "96° test," while the third sugar is returned into the factory process. To make first sugar, the syrup or "melatlura" is drawn into the vacuum pan continuously from the time the grain is ft)rmed until the pan is full of massecuite, some first molasses being usualK' elrawn into the pan towards the end of the operation. When the pan has become filled with massecuite (called "first massecuite"), the contents are discharged first into a mixer and then into the centrifugal machines, where the crystals are separated from the molasses, as described on the following page. The sugar thus obtained is called "first sugar" and the molasses, which is thrown off, is "first molasses." The molasses is pumped to storage tanks abo\-e the pan floor where it is heatcil, ami diluted with water to a tlensit)' of about jo degrees Baume, equivalent to 54.J degrees Brix, to be used in making second sugar. In the making of second sugar, the ]ian is filled to about two-thirds capacit\- with grain formed as previously described; then half of its contents is drawn o\er into an adjacent empty pan. l-'irst molasses is then drawn into both of these pans and boiled down. As the concentration proceeds, the sucrose crystallizes out of the molasses on to the prexiously formed grain. The crystals in this "second massecuite" are then separated from the mo- lasses in the centrifugal machines in the same manner as for first sugar. This second sugar, having an average polarization of a trifle less than 96°, is mixed with first sugar as previously described. The second molasses is diluted and heatcil in the same way as the first molasses. Third sugar is made in the same manner except that second molasses is drawn into the pan instead of first molasses. After the required boiling in the pan, the massecuite is discharged into crystallizers. These are large c^■lindrical tanks jirovided with stirring mechanism, each crystallizer usually having a ca]>acitv equal to that of a vacuum pan. The massecuite is slowly but constantly stirred in these crystallizers for a period of from three to five days and during this time the grain continues tt) grow until the massecuite is cooled to atm(«pheric temperature. When this process, which may be considered as a continuation of the \acuum pan work, is completed, the massecuite is discharged into the centrifugals antl treated in the same manner as the first massecuite. The resulting crystals are then mixed with meladura or first molasses and are used as "seed" grain m the pans in making first sugar. [Page 5 o 1 The Story of C v v, a n S i' g a r ^ - ' — — -^-^^^^ .V Separation of the T TTHEN the first or second massecuite has Q-ysta/s from tfie f/i^ '-^^^" •-'"•'etl to a proper density the entire z^olasscs contents ot the vacuum pan are dropped into a ^'-shaped mixer equipped with paddles which revolve and keep the massecuite from hardening. From here it is drawn into the centrifugal machines as required. Each of these machines has a strong perforated bronze basket, about 40 inches in diameter and 24 inches in depth, lined with a very fine screen. After having been tilled with massecuite the basket is made to rotate at a very high speed (about 1,000 revolutions per minute). This centrifugal motion separates the crystals from the mo- lasses and forces the latter through the screen. The process is termed " drying of the crystals" or "purging. " After a \it\\ minutes' operation, the machine is stopped and the almost dry sugar, now of a light brown color and packed against the walls of the basket, is discharged through a plate valve on the bottom of the centrifugal. 'lagging and I HE sugar is then carried by a screw conveyor to Stori?l7 ^ mechanical elevator where it is deposited in a large storage hopper overhead. From here it is fed by gravity to automatic weighing and bag-tilling scales, which also record the number of bags tilled. As a rule, raw sugar is bagged without any dry- ing other than that received in the centrifugals. It is packed usually 325 pounds to the bag in jute bags imported from India. An empty bag ordi- narily measures 29 by 48 inches and weighs about 2.'; pounds.* During crop time, work in the sugar house goes on day and night, gener- ally in six-hour shifts. A great portion of this work, as well as the stevedor- ing of the sugar, is done on a contract basis. The storage of raw sugar without loss in polarization has been, and still is, a subject of much study. To possess good keeping qualities, raw sugar should be well made in a clean factory, should polarize not less than 96 degrees and shouki have a moisture content not in excess of i per cent. The crystals should be of good size and should have received little or no washing in the centrifugals. The modern central is provided with a suitable ware- house of adequate capacity where the bagged sugars are automatically handled and properly stored until shipped. According to the best practice in Cuba, the bagged sugar is not piled more than eighteen tiers. Until about forty years ago, it was the general practice in Cuba to export raw sugar in hoasheads. [Page 5 I 1 The Story of C ii B a n Sugar .){ rcfiniiiL; process (condensed flow-sheet) on page 7c. (Page- 6 o 1 The Story of Cuban Sugar -o?- -5«. J'acHuin Paris — Where the Siwar Cr\stals are Formed ' f urging" the Sugar in the Leutrijugats [Page 6 i] The Story of Cuban Sugar ■.V The Finished Prodncl — Packed in lumeli and Bags immediately be- low, which are simply scroll con- veyors equipped with mixing flights. There the rawsugaris mixed with wash syrup to soften the film of molasses ad- hering to the sur- face of the crystals. It is next sent to the centritugal machines, ot the type used in raw-sugar manufacture, where the molasses coating is separated from the crystals. These crystals are then washed with a measuretl c^uantity of cold water while the machines are rotating. As refining consists in separating the pure sugar from its impurities, the removal of this molasses film, containing most ot the impurities ot raw sugar, may be considered as the first important step in refining operations. The products of this process of separation are two: first, a washed sugar of greatly improved color and purity; second, a wash syrup of comparatively low purity, which can be handled better separately. The washed sugar is dissolved in about one-halt its weight ot hot water [Page 6 ; 1 The S t o r V of Cuban Sugar -05- -5©. The Finished Product — Packed in Cartons in tanks called "melting pans," equipped with mechanical stirrers. The resultant solution, dark brown and cloudy, is pumped to the filter house for further purification. Some of the wash syrup is used for mixing with the raw sugar in the minglers — as previously explained — and the excess is sent to the filter house, where it undergoes much the same process as the sugar liquor. Filter House J- UDS HE washed sugar liquor is pumped to the "blow- ups "where its temperature and density are adjusted, and some suitable porous filtering medium, as, for ex- ample, phosphoric acid and lime, infusorial earth or macerated paper pulp, is added to make the liquor more adaptable to filtration. These blow-ups are iron tanks fitted with steam coils for heating the liquor, and are equipped with con- ical bottoms to lacilitate drainage. The sugar solution is next pumped through mechanical filters where the suspended impurities are removed. The filtered Hquor, now of a clear brown color, is passed through char filters (large cylin- drical tanks) filled with boneblack (animal charcoal, or bone char). These char filters remove the coloring matter and some of the soluble impurities, the process giving a sugar liquor as clear and colorless as the purest spring water. The clear sugar liquor is followed on the boneblack by syrups from [Page 63] The Story of Ci'ban Sugar -o§- -h^ Loading Truck Kilh Su^rar which some granulated sugar has been boiled, ami these in turn by other material ot still lower grade, such as mechanically filterctl wash syrup. From all these the boneblack removes color and impurities, in decreasing amounts as its absorbuig power becomes exhaustetl. The exhausted boneblack must next be "washed off," so boiling water is admitted to the filter. This displaces the sugar liquor and when the out- flow of the filter becomes dilute, the sweet water is di\ertcd to the "sweet water" tanks. This sweet water is mixed with other similar solutions and is concentrated in evaporators, ot a type similar tf) that used in a "central," and re-enters the blow-ups to begni the jirocess o\-er again.''' N\ hen the sweet water from the char filters becomes so low in purity as to be worthless tor further sugar recovery, it is run to waste. The washing ot the bone char is continued several hours more to remcn-e the impurities it has absorbed. Some of these, however, are so strongly held by the boneblack that water will not remoxe them and heat must be resorted to; accordingh', the boneblack is discharged from the filter, partially dried, then heated in special kilns. * The evaporators in a raw suaar factory plav a verv important part in the process of manufacture, as all of the clarified cane iuice goes through them for concentration. In a refinery, however, they do not have the same relative importance, beina used only tor concentrating the "sweet water." [ P a g e 6 4 1 'O^- T H E S T o R -i' of C u 1? A N Sugar =5^ Biiticry ijj J'nn'.^ U These kilns are so constructed that the char passes through in a continuous stream, but air is excluded since an unregulated air current at this stage would be fatal to the life of the boneblack. This treatment, to a considerable extent, restores the purifying properties of the char and it is used and re-used until those properties are entirely exhausted. T*a?i House <:Lyi^l FTER char filtration has been effected, the sugar solution, or liquor, is pumped to the pan house. Here it is drawn into vacuum pans and concen- trated at a low temperature under approximately twenty-six inches of vacuum until it has formed a magma, a mass of crystals mixed with a small quantity of syrup, resembling in character the massecuite of the raw-sugar factory. This crystallization is a very important stage of refining, as the temperatm^e at which the sugar is boiled and the method of forming the grain determine the character of the finished product. The men who do this work, known as "sugar boilers," are of long experience and training. The magma is purged in the centrifugals, the crystals being separated from the syrup and slightly washed with a mechanically controlled spray of purified water. The sugar is then automatically discharged from the machines [ P a g e 6 5 ] The Story of C i; b a n Sugar -o?- '5«. Cooperage I'uDti Lxicri'jV anti is passed througli long revolving drums, calleil "granulafors," and thoroughly i.lricd in a current ot hot air. The light colored syrups Irom the centrifugals are re-boiled with liquor to protluce more granulated sugar. The darker syrups are either re-boiled to remove the remaining sugar, which is then re-melteil and re-enters the process, or they are rc-tiltered through bone- black and boiled tor a sott or brown sugar, which is sold as such. The final exhausted resielue from the centrifugals constitutes refinerv svrup. The latter is protluced either as filtered syrup or as blackstrap, according to the demantls of the trade. Fi?lis/ii/liJ- House ^ / ^E. dried granulated sugar is screened into various J^ sizes and is packed in barrels, bags or cartons. The work of packing is done almost entirely by machiner\-, the sugar flowing from overhead bins into the various containers. The barrels are first lined with paper by hand and are automatically shaken while the sugar Hows into them. This shaking aids in filling them to capacity. 1 1' a g e 6 6 I The Story of Cuban S ii g a r Cvopcragc Phvil — Interior Each barrel of sugar is headed and weighed separately and the weight is marked thereon. It is then sent by a conveyor to the shipping room or the warehouse. A single machine automatically fills a bag with the required amount of sugar, sews the mouth and discharges the full bag into a chute leading to the shipping room. The carton-packing machine automatically fills, weighs and seals the two and five-pound packages of granulated sugar, operating at the rate of thirty per minute for the former and twenty-six for the latter. For powdered sugar, which is generally packed in one-pound cartons, the machine performs the additional work of inserting a lining of wax paper before the sugar is admitted into the cartons. Cubes and tablets are made by a process of pressing moist granulated sugar into molds and then drying them in ovens. CooperaP'e fT'is, evident that a refinery, requiring containers in / such quantities for its products, cannot risk depend- ence upon the usual sources of supply in the open market. Consequently, a well-equipped cooperage plant is operated as an [Page 67I The Story of Cuban Sugar ^ -.V adjunct to the modern refinery, producing all the liarrels and wooden cases necessarv for the packing ot its sugars. Elm, gumwooei and other semi-hard woods are largely used, the hulk ot the supply commg from Kansas, Missouri, Mississippi and Louisiana. ^J^arkctUl'J' /he sugar product ot the refineries is sold to the J^ confectionery antl other manufacturing trades and to wholesale grocers and jobbers, either directly or through brokers, tor domestic use, or through brokers tor export. The wholesale grocers and jobbers sell to the rctad traiie, which in turn supplies the indi\'idual consumer. The filtereii syrups and blackstrap are soKl either directly or through brokers, to blenders, exporters and jobbers. The syrups are sold on the basis ot their color, clarity and chemical analysis and are used tor human consumption. The blackstrap is used tor the same purposes as the final molasses ot a raw sugar factory, i.e., it is either distilled into alcohol or used as feed tor live stock. 'T)eIi'Very /J RAILROAD siding furnishes facilities for the V_-^^ shipment of full carload lots ami a fleet of" auto- mobile trucks makes prompt delivery in local and adjacent territory. "Disposal of C/npty * MHE empty jute bags, after being washed in hot T{aw-Sucrar '^a^s -^ water to remove all adhering sugar particles, are sold as second-hand bags and eventually find their wa\- into the potato, coconut and other trades. Only in times of extreme shortage of new bags are these washed bags mended and re-shipped to Cuba to be used again as raw-sugar containers. They prove unsatisfactory for this purpose, as the washing weakens the fibre. It is interesting to note that the Revere Sugar Refinery makes it a prac- tice not to wash the best of the empty bags. These are mechanically dry- brushed tor the recovery of any ailhering sugar, mended by sewing machines, baled and returned to Cuba to be used a second time by the United Fruit Company for shipping its raw sugar to Boston. This practice has proved highly economical and efficient as, when the bag is dry-brushed, the fibre is not weakened. [ P .1 g e 6 8 ] The Story of Cuban Sugar •^r- ■5©. Qonclh ■ISlOfl CL/J^er SUGAR refinery operates on the basis ot the differ- ence between the cost of its raws, including the im- port ciuty, and the selling price of its refined sugar. On this narrow margin it must pay all manufacturing expenses, including the loss due to the impurities in raw material, as well as the cost of packing and selling. It is essential that a refinery have deep water for directly receiving its raw-sugar cargoes. Moreover, its location should afford a good supply of labor, coal and water, in addition to adequate rail and highway transporta- tion for the delivery of its products. All these factors, together with the increasing number of fancy grades of refined sugar demanded by the public, have resulted in the concentration of the industry in a few large refineries, situated for the most part at the large Atlantic seaboard centres, with daily productions ranging from 1,000,000 to 5,000,000 pounds. * See page 5 5 Table of Allowances and Deductions for Raw Sugar Polarizing Above AND Below 96 Degrees, Respectively Effectit'f lotth crop of igig — ig20 AUowanct !• er Degree Allowauct per Degree 95 to 9' Price pc /■ Pound 96 to 95 Above 97 96 to 97 C and F Duly Paid C and F Duty Paid C and F Duty Paid Cents Cents 5.00 5.999 6.00 — 6.999 10 pts. 12 pts. 5 pts. 1 pts. 6.00 6.999 7.00 7.999 II 13 " 5K iH " 7.00— 7.999 8.00 — 8.999 12 14 " 6 8 8.00 8.999 9.00 9.999 ^3 15 " 6K 8J2 " 9.00 9.999 10.00 10.999 14 16 " 7 9 10.00 10.999 I 1. 00 — 11.999 15 17 " 7K 9K " 11.00 11.999 12.00 12.999 16 18 " 8 10 Fractions of a degree in p re portion. Forpriceshigherorlower than those that appear in this table, the allowance to the seller on sugars over 96 degrees (but not exceeding 97), and to the refiner on sugars under this figure, increases or decreases one point (1 cent per 100 pounds) for each cent of increase or decrease in price. The rate of allowance to sellers for polarization over 97 degrees increases or decreases one-half point ('< cent per 100 pounds) for each cent of increase or decrease in price. [Page 69] The S t o r -i' of C r n a n S h g a r -=»5- -5©. Refinery - ConDEMSED FLow Sheet MeltHouse I I ■STorsy^Cr^ £>ir/5 I CE:rrrRiFuqAi-s\ \MELTirilov^ Uf=s h \E>Orf£:E>i-y^<^K F~/L.TE/S^ ^ 3_ \Kii-nt,\ I EvAF^I^ATtPf?^ F^aj-f House. VVacuum F'AriS) 1 I I CEnTFllFUCA.L.^ I I I /ggA/g^r-StAj^ie"! ISoFr^t/q/i/gF |.Pi'^/^f5t/