RECEIVING, SAMPLING, AND GRADING. 



95 



sample, the test of that composite sample will be 3 + 5 -^-2, 

 or 4%. According to this test, these 300 pounds of milk 

 delivered will contain 12 pounds of butter-fat. In reality 

 6 pounds of fat were delivered in the 200 pounds, and 5 pounds 

 of fat in the 100 pounds, making a total of 11 pounds of fat. 

 Thus we see that the dipper method is not reliable, and in this 



-80 

 -70 

 -00 

 -50 

 -10 

 -30 



-20 

 -rlO 



FIG. 55. The McKay cream and FIG. 56. Cream sampling-tube, 

 milk sampler. 



case the patron was paid for 1 pound of butter-fat too much 

 for the two days' delivery. If the sample taken from the 

 200 pounds of milk had been twice as great as that taken from 

 the 100 pounds of milk, then the composite test would have 

 been perfect, no matter whether it had been taken with a 

 dipper or with a sampling-tube. If the same weighing-can 

 is used every day, then an exact proportion for a sample can be 



