CHAPTER XXV. 



THE CONTROL OF THE FACTORY. 



By the term ' chemical control ' it is not meant that the control of the 

 factory should be given over to any one but the manager, but there is implied 

 a system of routine analysis and sampling combined with an organized scheme 

 of technical book-keeping whereby the chemist can detect, locate, correct and 

 hence control any imperfections of the process of manufacture. 



To obtain this end three postulates are demanded, correct weights, correct 

 samples and correct analyses ; neglect of any one of these three will vitiate 

 the control, but as shown in some sections below incorrect measurements may, 

 in some cases, be indicated from analytical data alone and it is not the least of 

 the duties of the chemist to check the weights against the analyses ; this is 

 particularly the case where the cane is bought or where its weight forms a 

 basis of payment for the labour. 



In addition the sugar factory should be regarded as a huge chemical 

 experiment and efforts should be made to account for every pound of sugar 

 entering the factory. The points necessary to the control as denned above are 

 discussed below. 



Direct Measurements. Canes. What is regarded as the weight 

 of cane is not the same in all factories ; in some the gross weight is used and 

 in others an arbitrary allowance is made for trash, dirt, &c. ; there can be no 

 doubt that, for control work, the weight of cane should be denned as that 

 material which actually passes between the rollers of the mills. 



The balances used to weigh canes are of the conventional type ; they 

 should be repeatedly checked and adjusted and the (in general) native clerk 

 should be carefully watched especially when the weight of cane forms a basis 

 of payment to contractors or when canes are purchased from native planters. 

 ."Balances automatic in action and self -registering are to be bought, and these 

 are beyond the control of the operator whose functions are merely mechanical. 



Juices. In most factories the determination of the weight of liquids is 

 obtained from volume measurements and when carefully conducted and con- 

 trolled accurate estimates are possible. The most convenient scheme is to 

 employ two or more tanks for the reception of the cold juice, which also may 

 serve as liming tanks ; in each of these tanks a slot is cut on one side and the 

 flow of juice is continued until it freely overflows ; a constant volume is thus 

 ensured; the overflow is received in a gutter and returns to the juice pump 

 tank. The volume of juice combined with density and temperature 



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