THE CONTROL OF THE FACTORY. 



Horsin -Dean's Apparatus, shown diagrammatically in Fig. 272, is designed 

 to record the height of the juice in the receiving tanks. A wire or chain a a 

 transmits motion from a float b in the tank to a drum c which revolves when 

 the float rises or falls ; a pinion d on this drum in turn drives a rack e which 

 carries a pencil / pressing against a cylinder g which revolves once in every 

 twelve hours ; the height to which the pencil rises is governed by the height 

 of the juice in the tank, and, conversely, the pencil will show if the measuring 

 tanks have been properly emptied or whether through .carelessness any 

 1 running on bottoms' has occurred. 



Dilution. The dilution is calculated either as a percentage on the 

 normal juice expressed or as a percentage on the mixed juice. If B l and JB 2 

 are the degrees Brix of the normal and of the mixed juice, then water present 



7? 7? 



in mixed juice per unit of normal juice is given by the expression ^= - - 



and per unit of mixed juice by the expression 



B 



In this calculation it is not unusual to take B l as the degree Brix of the 

 first mill juice ; in other cases a factor is used to connect the Brix of the first 

 mill juice with that obtained when the mills work without added water. 



Extraction. The extraction is the amount of sugar obtained in the 

 juice per 100 sugar in canes; where direct measurements are used this 

 figure is at once obtainable ; in the majority of cases this is not the case and 

 resource must be had to inferential methods which were first used by leery. 3 

 If /be the fibre in the cane, and m be the fibre in the megass, then the weight of 



megass per unit weight of cane is and the weight of juice per unit weight of 



cane is 1 = - - . Consequently if the fibre in the cane and in the 

 m m 



megass are known, and also the weight of either the juice or the megass, the 

 other data can be calculated ; an example is appended. 



Recorded Data. Tons of cane 550 ; tons mixed juice 500 ; fibre in caiie 

 11 per cent.; fibre in megass 44 per cent.; sucrose per cent, in mixed juice 

 13 per cent. ; sucrose per cent, in megass 4*0 per cent. Then 



Tons megass = X 550 = 137-5 

 44 



Tons sucrose in megass = 137*5 X *04 = 5*5 

 Tons sucrose in juice = 500 X * 13 = 65-0 

 Tons sucrose in cane = 65-0 x 5*5 = 70-5 



Extraction = -- - - = 92*19 per cent. 

 70'5 



Sucrose per cent, in cane = - = 12*81 per cent. 



550 



501 



