THE CONTROL OF THE FACTORY 561 



guide to direct the operations and those on which the statement of yield and 

 losses is made. For the latter to have their full value sucrose and not polariz- 

 ation should be returned and all statements should be based on the former.* 



The writer regards the following scheme as sufficiently detailed. 



First Expressed and Last Mill Juice. Brix, polarization, in six-hourly 

 composite sample. 



Mixed Juice. Brix, sucrose, reducing sugars in 24-hourly composite 

 sample. 



Syrup. Brix, polarization every three hours. Gravity purity in 24- 

 hourly composite sample. 



Bagasse. Water, polarization, every hour. 



Massecuites and Molasses in Process. Brix, polarization, purity, each 

 strike. 



Waste Molasses. Brix, polarization, purity from each container. Peri- 

 odical detailed analyses including gravity solids in appropriate dilution, 

 sucrose, gravity purity, reducing sugars and ash, in composite sample. 



Sugar. Polarization, water per cent., every two hours. Periodical 

 detailed analysis as for waste molasses. 



Press Cake. Polarization every six hours on composite sample. 

 Condensed Water. Polarization in composite 24-hour sample. 



Records. In the technical accounting of a sugar-house, distinction should 

 be drawn between the " weighted average " and the simple average. The 

 former is used when the weights of the material are known and when a balance 

 is required. The latter used when the weights of the material in question are 

 not recorded, and where a great degree of exactitude is not demanded. 



The " weighted average " is determined periodically by a reversed 

 operation after the total of the materials over a period has been found 

 as the sum of the daily quantities. An example will make the method to 

 be used clear. Over a period of seven days the daily quantities of mixed 

 juice, of sugar therein and sugar per cent, were : 



Mixed juice.. 563-4 1180-2 1263-4 1187-2 1251-4 923-5 1151-2 .. Total 7520 -3 

 Sugar in juice 81-3 169-9 176-0 167-4 177-8 149-1 158-7 .. 1080-2 

 Sugar per cent. 15 -42 14-40 13-93 14-10 14-21 16-15 13-80 



_,.,,, , . IO8O -2 



The weighted average sugar per cent, is = 14-39 P er cent. 



The simple average of the daily determinations is 14-58. 



If, for example, in the ten previous weeks there had been recorded 

 80192-1 tons of mixed juice and 11170-5 tons sugar therein, the totals to 

 date will be 87712-4 and 11250-7 respectively, giving the to-date iigure for 



11250-7 

 sugar per cent, as ^ ^ - 12-83 per cent. 



The quantities which should be worked out as actual weights daily and 



* The very great majority of cane factories in Cuba, Java and Hawaii base their results on polarization as 

 opposed to sucrose per cent. In Mauritius, on the other hand, for the crop of 1918, eighteen houses, out of thirty- 

 three reporting, used the more rational basis. 



2P 



