KEEPING OF BOOKS. 



307 



In the first place, a record should be kept of the annual yield of 

 milk per cow, its average percentage of fat, and the annual yield of 

 butter, in order to form a basis for the economic valuation of the 

 individual cows. Further, the books must exactly indicate how 

 much of the milk supplied to the dairy is used, and how much is 



Fig. 84.-Machine for Weighing Milk. 



sold; how much is treated, and what amount of bye-products are 

 obtained; what loss the bye-products involve, and what value they 

 fetch. In addition, calculations should be made with regard to all 

 the bye-products, by which the yield, both with regard to quality 

 and quantity, as well as the amount of working expenses, is influ- 

 enced. Records should also be kept of the temperature of the milk, 

 cream, and skim-milk; and, in the case of cream-raising, particulars 



