162 Testing Milk and Its Products. 



184. If the diameter of the sampling pail used is 8 

 inches, and that of the sampling tube ^ inch, the quan- 

 tity of milk secured in the tube will always stand in the 

 ratio to that of the milk in the pail, of (1/2) 2 to 8 2 , 1 

 that is, as 1 to 256, no matter how much or how little 

 milk there is in the pail, the sample will represent ^ 6 

 part of the milk. For composite sampling of the milk 

 of single cows, this proportion will prove about right; 

 if more milk is wanted for a sub-sample, dip twice, or 

 pour the milk to be sampled into a can of smaller diam- 

 eter. If the mixed milk from a number of cows is to 

 be sampled, a wider sampling can may be used. By ad- 

 justing the diameters of the tube and the can, any de- 

 sired proportion of milk can be obtained in the sample. 



For factory sampling, with a weighing can 26 inches 

 in diameter, a tube three-quarters of an inch in diameter 

 will be found of proper dimensions. 



In using these tubes, the milk or cream must in all 

 cases be in cylindrical cans when the sample is drawn. 



The sampling tube will furnish a correct sample of 

 the milk in the can, even if this has been left standing 

 for some time; it is better, however, to take out the 

 sample soon after the milk has been poured into the can, 

 as the possible error of cream adhering to the sides of 

 the sampling tube is then avoided. 



185. The accuracy of the sampling of milk by means 

 of the Scovell tube was proved beyond dispute in the 

 breed tests conducted at the World's Columbian Expo- 

 sition in 1893, in which tests this method was adopted 



1 The contents of a cylinder are represented by the formula Tfr^h, r 

 being the radius of the cylinder, and h its height. The relation brtwrei) 

 two cylinders of the same height, the radii of which are 7\* and r. Is 

 therefore as 7TR2h to 7T r 2h, or as R2 to r2. 



