420 THE AMERICAN FARMER. 



This places the successive operations of defecating, concentrating, and finishing by 

 steam under the immediate and convenient control of the sugar-maker. The heat is readily 

 increased or diminished or withdrawn from either vessel at pleasure. 



As sugar-making by a connected steam train is a continuous as well as rapid process, it 

 is important that proper arrangement and proportion of all the parts be provided, including, 

 also, the even and reliable working of the mill, so that the continuity of the operations may 

 be harmoniously and effectively preserved to the end. 



Whilst beyond question steam is the best agent used in boiling cane- juice, and the con 

 nected steam train the most perfect and simple apparatus, the effectiveness of the latter may 

 be seriously impaired or totally destroyed by ignorant management, or improper proportions 

 of vessels and pipes. In these, experience and skill are absolutely necessary. 



If the planter has an engine and boiler of sufficient capacity to run his mill, and plenty 

 of steam to spare, he can use steam profitably for working up even a small crop, either with 

 steam pans entire, or with steam pans for defecating and finishing, and a fire evaporator for 

 concentrating.&quot; 



The chief objection to the open pans in the evaporating process is in the high tempera 

 ture required to boil sugar solutions in the open air, which converts much of it into glucose. 

 Vacuum pans, therefore, are greatly to be preferred. 



Crystallization. After a perfect cleansing or defecation of the juice, and its rapid 

 evaporation to the sugar point, the next step in the process is to secure crystallization. When 

 this condition is reached is a somewhat nice point to determine, for one not experienced in 

 the business. The common test is, that when the liquid has reached that degree of concentra 

 tion that a drop of it, placed between the thumb and fore-finger and pressed, may be drawn 

 into a thread which has a granular appearance, it is an indication that the evaporation is 

 complete, and it is ready to be transferred to the cooler. This should be large and shallow. 

 As the sugar gradually cools and crystallizes, it should be occasionally stirred to make the 

 granulation as uniform as possible. A small quantity of granulated sugar, mixed into the 

 syrup as it cools, will hasten the crystallization; hence, by putting a little into the first that 

 is drawn off into the coolers, and permitting some of the sugar to remain attached to the 

 bottom and sides, as they are emptied each time, to be again refilled, will materially aid in 

 this process. 



After the sugar has crystallized in the coolers, it must be separated from the molasses, 

 or syrup, that does not granulate. This is done by various methods of draining. Large 

 tanks, tubs, or boxes, perforated at the bottom, and provided with movable plugs, or false 

 bottoms of slats covered with coarse sacking, for straining out the liquid portion, are some 

 times used;, but the best method is the centrifugal machine, which rapidly expels the 

 molasses from the siigar by force, leaving the latter quite dry. This is a great improvement 

 in sugar making and refining. 



There are various kinds of centrifugal machines. They are constructed with a cylinder, 

 the walls of which are formed of finely perforated metal. This is supported, and with 

 proper appliances, is made to revolve with great rapidity, from a thousand to eighteen 

 hundred times a minute. The sugar is placed inside the cylinder, and the machine set in 

 motion, which causes the sugar to form a lining of uniform thickness on the interior, while 

 the molasses is driven through the perforated metal and caught in the drum that surrounds 

 it. The machine is then stopped, and the sugar scraped out. By this means the separation 

 of the sugar and molasses may be easily accomplished in a few minutes, while it might 

 require days by the former draining process. The yield of sugar varies from half a ton 

 to two and a half or three tons per acre, according to the variety of the cane, methods of 

 culture, soil, season, and the efficiency of the machinery employed in its manufacture. The 



