280 soRGrruM. 



feet per minute, and another with rolls 36 inches in diameter, and 66 

 inches long, the average speed being 9 feet per minnte. 



The first gave 59.9 pounds of juice from each 100 pounds of cane, 

 and the latter 77.61 pounds of juice to 100 pounds of cane. The first 

 gave 9.36 pounds of sugar from each 100 pounds of cane, the latter 

 14.87. One gallon of juice from the first gave .572 pounds of mo- 

 lasses, and 1.672 pounds of sugar, and 1 gallon of juice from the 

 other gave .66 pounds of molasses, and 2.07 pounds of sugar. 



According to this calculation, there Avas lost in the bagasse of 

 each 100 pounds of cane ground 7.53 pounds of sugar in the first case 

 and 2.47 pounds in the latter, equivalent to an increase on tlie crop of 

 46.6 per cent by the slow mill. The above experiments were made 

 Avith sugar-cane, but Avill illustrate the principle. Very many exj^eri- 

 ments are reported from Louisiana bearing upon this question, but 

 generally a difierence in the cane used in the two cases vitiates the 

 result. 



VARIOUS METHODS FOR THE EXTRACTION OF JUICE. 



Although the three-roll mill of capacity suited to the requirements 

 is the ordinary method employed in the extraction of the juices from 

 sugar-cane and sorghum, it is, of course, to be expected that many 

 other methods have been devised to accomplish this result Avithout the 

 enormous and inevitable loss Avhich the system of simple crushing of 

 the cane involves. 



It is proposed briefly to refer to those several methods which have 

 been devised, more for the purpose of stimulating ex2;)eriments and in- 

 vention than for the full elucidation of the difierent processes. 



The several methods devised for the extraction of sugar may be 

 classed as folloAvs: 1. Multiple rolls ; 2. Disintegration of the cane; 

 3. Maceration ; 4. Diffusion. 



1 . Multiple Rolls — Auxiliary Mills — Doiible Crushing. 

 One of the largest mills in the Avorld is that belonging to the Khed- 

 ive at Aba-el-Wakf, in Upper Egypt. This is a three-roll mill, each 

 roll being 48 inches in diameter and 5 feet 6 inches long. The length 

 of time during Avhich the cane remains under pressure (tlie surface 

 velocity of the rolls being the same) is proportioned to the diameter of 

 the rolls, and although running Avith a velocity of 36 feet per minute, 

 this immense mill is said to express as high a percentage of juice as 

 the ordinary three-roll mills do at half the velocity. This large per- 

 centage of juice obtained Avith large rolls is due not alone to increased 

 and prolonged pressure, but to the fact that the juice escapes from 

 contact Avith the bagasse, and thus less of it is absorbed. There is an. 



