322 



CITY MILK SUPPLY 



cuts that representing the automatic machines at 13,000 thus signifying 

 that in plants handling from 3,400 to 13,000 bottles the rotaries are more 

 suitable than the automatic machines. The filling and capping machine 

 curve crosses the hand-capping curve at 5,500, the automatic at 11,000 

 and the rotary at 27,000 and so indicates the field that the filling and cap- 

 ping machines can profitably occupy. These suppositions cannot be laid 

 down as rules because other factors than those considered affect the costs. 

 In these estimates the cost of power to run the automatic machines was 

 not included and definite figures as to the depreciation of the rotary 

 machines were not available since they have but recently been put into 

 service. The number of machines in use at a plant affects the cost. 

 Thus, with one method of filling and capping, in 10 plants using one 

 machine 766 bottles were handled per man per hour, while the number 

 at five plants using two machines was 904 and at two plants using three 

 machines was but 629. The chief reasons for this are: that often two ma- 

 chines were operated with one man less than twice the number necessary 

 to operate one machine, thus reducing the operating cost; when three 

 machines were used, one was often idle because a great deal of the time 

 not enough milk was handled to keep more than two machines busy. 



The number of men used at different plants with each type of machine 

 is shown in Table 92. 



TABLE 92. NUMBER OP MEN USED IN OPERATING DIFFERENT TYPES OF FILLING 

 AND CAPPING MACHINES (U. S. DEPARTMENT OF AGRICULTURE) 



Bottle Cases. As soon as the bottles are filled and capped they are 

 put in the cold room, being sent thither in the larger plants over roller 

 conveyors and in the smaller ones by trucks. The cases or crates that 

 hold the bottles, like other dairy implements, have been improved. The 

 first were entirely of wood and, while they had the advantage of being 

 light, were not easily cleaned and being absorptive soon became smelly; 

 moreover, they wore out quickly. Substituting removable metal par- 

 titions for the wooden ones was an improvement but these crates gave 

 place to those made entirely of galvanized iron. They were more dur- 

 able and more easily kept clean and free from odor but they were much 

 heavier. Furthermore, metal is a good conductor of heat and cold, so 



