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to the end B, the green scum is drawn over the sloping side into the gutter C, from which it is conducted into a reservoir provided for its reception, from B the thickened juice passes into D, and is finally discharged into the vessel E.
I have already stated that when a strong solution of sugar be kept sometime near its boiling point it is gradually changed into uncrystallizable sugar; hence arises the necessity for rapid evaporation at low temperatures and from thin masses. This principle is much better understood in Ohio than in Illinois, and is very well carried out in Cooks & Jacobs' pans, which are more extensively used in that State than any others.
Three distinct impurities should be separated from the syrup in the process of evaporation.
The first, is a green scum consisting of chlorophyl, pectin and (albuminous matters, which is thrown up in great abundance on the fore-part of the pan, it must be removed continually with the skimmer.
The second, is a resinous gummy matter of a grayish color, which forms a pellicle on the hinder part of the pan of the consistency of spermaceti. It does not form until the juice reaches a density of 16 deg. B, nor unless the surface is still; ebullition breaks it up into small particles which are suspended in the juice and they cannot afterwards be removed, its taste is very disagreeable and it resists the granulation of sugar.
The third is a white saline deposit which forms upon the bottom of the pan. When allowed to accumulate, it forms a hard coating, which can bardly be removed by the chisel. Mr. Wm. Clough, editor of the Sorgo Journal, procured an analysis of this matter; he informs me that it copsists chiefly of the binoxalate of lime, but that he believes it will vary in different places, according to the composition of the soil.
Mr. Jacobs gets clear of this cement by setting his pan over the fire and burning it; others put straw into the pan and burn it. After either of the above modes of treatment it scales off the bottom very easily with a chisel. Mr. Wm. Edgerton washes it off with the sour scum; but the easiest mode is to wash it with dilute sulphuric acid (see Cook's sugar evaporator, fig. 8).
The operation of this pan will be understood at a glance. The juice is contained in the reservoir at the end nearest to the furnace door; the cock being kept open enough to keep a stratum of juice in the bottom of the pan from a half to a quarter of an inch in thickness, it flows in a zig-zag direction around the end of the partitions. It will be observed that the edges of the pan project over beyond the furnace; the juice, therefore, is cooled down as often as it passes round the end of the partition, which prevents it from boiling over. It is known that syrup will throw up a scum as often as it is boiled, after cooling. The advocates of this pan assert that the frequent coolings which it occasions purifies the juice more perfectly than any of its rivals can do it; but its opponents assert that these coolings are themselves the causes of the degradation, and deny the inferences of the friends of the Cook pan. The rockers are to regulate the flow of juice. It is used by a greater number of sugar makers in Ohio, and has taken the premium at more fairs than any other. I have unfortunately lost my price list of the Cook pans; but I believe they do not differ materially from those of Jacobs' pans.
I have already given a view of Jacobs' pan, set in brick work, at p. 51; below I give a view of it in a portable form (see Jacobs' evaporating pan in a portable form, fig. 9). The prices are as follows:
Evaporating Price List. Jacobs' patent evaporator and clarifier, complete, with two pans, two double door fronts, two sets of grate bars, two arch irons, anchors, skimmers, &c., ready for brick work
No. 1, complete; capacity, 3 to 5 gallons of syrup per hour.. ..... $50 00
5 to 8
Evaporators with Portable Furnaces.
2, The Cook pan may be procured of the Clark Sorgo Company, Cincinnati; the Jacobs pan of J. L. Gill & Son, Columbus, Ohio.
Although the Cook pan has taken the greatest number of prizes at the fairs, it is a curious fact that the syrup from Jacobs' pan has taken the premiums at the saine time.
I made many careful comparisons of the syrups made on these rival pans, and am compelled to acknowledge that those made on Jacobs' pan are the best; and I am of opinion that it requires less labor and fuel. I therefore fecl constrained to recommend them to the farmers of New York. It is due to candor to state that the proprietors of the Cook pan assure me that I had not seen it operated by any one whom they considered as truly expert in the use of it. It is true that I saw Jacobs' pan used by those who were most skillful, among whom was Mr. Jacobs himself; but I also saw others who had just begun to use it, and I considered it as a great commendation of it that these raw beginners were able to make nearly as good syrup as those who were most accustomed to its use. Mr. George Wigands, of Grove city, Franklin co., Ohio, had been accustomed to use the Cook pan, but had discarded it for Jacobs' about a fortnight before my visit. On comparing the syrup made hy him after this short apprenticeship, I found it decidedly superior to that which he had made upon the Cook pan, to which he had so long been accustomed. Mrs. Wigands had been obliged to relinquish working on the Cook pan, on account of the severity of the labor. She informed me that she could attend Jacobs' pan without fatigue, and was actually working at the time of my visit.
Both pans are based upon the principle of shallow evaporation; in both, a stream of juice flows constantly in at the upper end and out at the lower end in the form of syrup; but there is no zigzag flow in Jacobs', the juice flowing under instead of around the adverse partition. Both of them I believe are equally successful in removing the first and third of the above mentioned impurities, but Jacobs' is the only one which successfully removes the second.
The Jacobs pan as shown in the figure has seven transverse partitions
extending from one side of the pan to the other and running very nearly to the bottom. Each of these partitions operates as a skimmer, so that the feculencies thrown up from the first compartment cannot enter the second, nor those of the second into the third, &c.
It is obvious that the juice in each of the compartments must differ in density, and that the density must increase as it runs backward, the boiling point of each succeeding compartment is therefore higher than the one in advance of it, and throws up a different kind of impurity. There is no active ebullition in the two last boxes, but a lieavy, waxy scum accumulates upon the surface, which is probably the substance which gives the unpleasant herbaceous taste which has been so much complained of in sorghum syrup. When the juice leaves the pan it stands at about 24° B. hot. It is then transferred to the pan D, where it is rapidly boiled down to 36° or 41° B. cold if intended for syrup, but if designed for sugar it is boiled down still more. The granulating point is determined by taking a portion of syrup on the thumb, placing the fore finger upon it, and separating the thumb and finger so as to draw out a thread ; if it extends to about the length of half an inch the sugar is judged to have been sufficiently boiled.
All that is now necessary is to set the syrup aside in shallow vessels, which should be kept steadily at a temperature of about 80° F., crystalization is hastened by throwing in some crystalized sugar which seems to act as a nucleus for the forination of new ones.
When crystalization is effected, the soft mass is to be dipped into moulds, and kept warm until a loaf is formed, the stopper is then to be removed and the molasses allowed to run off. I do not consider it necessary to go any further into minutiæ of sugar making, as the farmers of New York will not probably ever engage in the business.
REFINING THE SYRUP. This is usually done at the sugar refineries by processes which are carefully kept secret by the proprietors, but as some of the farmers may desire to do it for themselves, I give the process of a Mr. E. S. Recker, who is the only farmer that I met with who made any attempt at refining. The
syrup is first concentrated to 38° B. After his cane is all worked up, he draws off a barrel of syrup into a clarifying pan 6 feet by 3 feet, and adds water enough to reduce it to 25° B., which takes about 30 gallons of water to 42 gallons of syrup. He then adds 2 gallons of bone coal dust and eight or ten eggs, or two gallons of milk; these ingredients are thorougly stirred in and heated to the boiling point. The pan is then withdrawn from the fire and allowed to stand two or three hours; the scum being removed, it is then strained through a flannel cloth into a large kettle in which the syrup is kept hot, from this it is pumped into a tub, shaped like an inverted churn, furnished with a false bottom over which is placed a double flannel cloth, the tub is filled with bone coal about eight feet high and the syrup is allowed to remain in it for three or four hours when it is drawn off from the bottom in a small stream; the tub is kept constantly filled with the hot syrup. After it has been thus filtered through the coal,