READING TEST BOTTLES. 



307 



less chance there is for errors. When 1 per cent on 

 the reading, of the test bottle takes up only 1/18 of 

 an inch, and 5 per cent takes up only 5/18 of an 

 inch, one can readily understand that the chances 

 are greater than with a bottle on which 1 per cent 

 takes up about 1/6 of an inch on the reading of the 

 test bottle, or 5 per cent takes up about 5/6 of an 

 inch, or nearly one inch. 



TABLE XIII. 



Comparative Length of the Oradiiated Part of tlic Keck 

 of Cream Test Bottles. 



86. Reading' of cream tests. 



We must not forget that in practical work there 

 must be a method for reading tests, which can be 

 quickly as well as accurately performed. In Bulletin 

 . No. 58, U. S. Department of Agriculture, we find a 

 short rule to be used to assist in reading cream tests 

 accurately. It- is as follows: "Read the test from 

 the extreme top to bottom of fat column ; deduct 

 from this reading four-fifths of the depth of the 

 meniscus and add .2 per cent to the results." This 



