40& THE OVERRUN 



ing of milk and cream for the fractions of pounds that fall be- 

 tween the smallest graduations on the beam of the scales ; they 

 provide no tolerance in the testing of milk and cream for fractions 

 of the per cent of fat that fall between the smallest graduations 

 on the neck of the test bottle; and furthermore, they assume, in 

 the calculation of the money due the farmer, that all fractions of 

 pounds of butterfat, even those of the last decimal are included, 

 making no allowance for the dropping of any fractions. 



But in practical operation these details do exist, and contrary to 

 the general impression, their occurrence very vitally affects the 

 actual overrun. 



It is not often that either the empty or the full can weighs 

 exactly to whole or half pounds. In the majority of cases the exact 

 weight is somewhere between the whole and half pound and the 

 operator has to choose between dropping the undeterminable and 

 unrecognized fraction or calling that fraction one whole or one- 

 half pound. 



Similar limitations of accuracy occur in the testing of milk and 

 cream, and particularly in the case of cream. The smallest division 

 marks on the neck of the standard cream test bottle record one-half 

 per cent and the distance between the graduation marks is very 

 minute, about one thirty-seventh of one inch, making it impractica- 

 ble, if not impossible, to determine and record fractions of less than 

 one-half per cent, and occasionally difficult to even distinguish one- 

 half per cent. 



But quite often the length of the fat column fails to exactly 

 coincide with the whole per cent or the half per cent marks and the 

 tester has to choose between dropping the uncertain, undeterminable 

 and unrecognized fraction, reading to the next lower line, or calling 

 that fraction a whole or a half per cent. 



Finally, the pounds of butterfat, as calculated from the pounds 

 of cream and the fat test, often represent an amount with three to 

 four decimals, rendering the computation of the money due the 

 farmer complicated, time-consuming, uneconomical and inviting 

 errors in the results. This has led to the practice on the part of the 

 creameries, of dropping some of these fractions, usually including 

 those of the second decimal. 



These unreadable and unrecognized fractions in the weights and 

 tests of cream have, in the past, failed to be considered in the treat- 



