196 



CITY MILK SUPPLY 



A charge of 15 cts. per man and 12 cts. per horse was made and the 

 cost of teaming the milk for each herd was calculated from all the milk 

 hauled from each farm during the year and the number of men and horse 

 hours required to move the year's product of milk to the factory or station. 



Temperature and Bacteria of Milk Increase in Hauling. Since 

 bacteria multiply rapidly in milk at temperatures above 50F. and 

 since the rate of increase is greater the higher the temperature, the 

 tendency for milk to warm up in transportation is a serious matter. 

 The U. S. Department of Agriculture in some experiments found that 

 when milk, cooled to 50F., was hauled in an open truck 13 miles on a 

 bright sunny day with the temperature at 82.6F., in 3 hr., cans covered 

 with hair-quilt-jackets showed a rise in temperature of 5.5, those wrapped 

 in wet burlap 8.5 and unprotected cans 28.5F. At Milwaukee, Gunn 

 studied this question and some of the measurements made by him are 

 set forth in Table 59. 



TABLE 59. RISE IN TEMPERATURE OF MILK COLLECTED BY WHOLESALE WAGONS IN 

 MILWAUKEE, Wis., AUG. 30, 1911 (GUNN) 



Air temperature at first collection, 50F. 

 Air temperature at last delivery, 70F. 

 To'tal miles traveled to city limits, 16. 

 Total time consumed on trip, 5 hr., 35 min. 



At Springfield, Mass., Gamble studied the relationship between the 

 temperature at which milk is transported and the bacterial count. In 



