96 



Watts -^ gives a table showing the approximate result with different 

 kinds of mills: 



According to the above, the hand mill used in making analyses of Negros canes 

 would when working very juicy and tender canes be considered about as efficient 

 as a very poor, single 3-roller mill, wliereas with canes containing 14 or 15 per 

 cent of fiber it would be said to approximate in power the work of two 3-roller 

 mills and crusher, without maceration. The differences obtained in actual practice 

 among 3-roller mills are by no means so great, but there is, as will be shown 

 later, a decided variation in the efficiency, calculated according to this factor, 

 of the same mill when working canes of different fiber content, so that the quotient 

 "mill juice per 100 fiber in bagasse," can not be accepted without question as 

 an absolute standard of efficiency of mill work, regardless of the kind of cane 

 ground. Given about the same composition of cane, it is of some value in deter- 

 mining the comparative efficiency of mills in the same neighborhood, and, in 

 conjunction with complete analyses of the canes ground, affords a ready method 

 for ascertaining the per cent of total sugar lost in bagasse by muscavado mills. 



The results of a mimber of determinations made on different mills 

 in Negros are here ^given. The usual method of procedure in taking 

 samples and preparing them for analysis was as follows: 



Samples, consisting of a few handfuls at a time of the bagasse as it came 

 from the mill, were taken at intervals of five or ten minutes and placed to dry 

 in a large coarse sack laid directly on top of the uncovered portion of the engine 

 boiler. At the same time four or five samples of 5 cubic centimeters each of 

 juice were taken directly from the mill bed and put in a liter bottle containing 

 0.2 gram mercuric chloride. Sampling was continued thus for three or four hours 

 until both bottle and sack were full ; the bagasse was then, as a rule, allowed to 

 remain for a few hours longer, while field samples of soil and cane were being 

 taken, by which time it was sufficiently dry to allow of its being transported a 

 considerable distance back to the laboratory. On arrival at the temporary 

 laboratory headquarters, the bagasse, was either analyzed at once or spread out 

 over the boiler there to keep dry until morning. The whole sackful was spread 

 out on a clean floor and chopped into coarse pieces, then quartered down to a 

 final weight of about half a kilo, which was chopped much finer and used 

 for analysis. The work of taking the original samples at the mill was all done 



^^ West Indian Bull. (1909), 10,' 109. 



