564 IOWA DEPARTMENT OF AGRICULTURE. 



urlng, the tests were accepted as showing the superiority of one herd over 

 the other so far as the test of the milk was concerned. 



In the course of time it so happened that a student of the Wisconsin 

 Agricultural College visited one of these farms and tested some of the 

 cows. While engaged in this work one morning he needed one more test 

 to make the tester balance and as the can of milk to be sent to the cream- 

 ery was near he took a test out of that milk and ran it with the others 

 from the single cows. The owner of the herd chanced to come around 

 as the completed tests were being read and he noticed that the test of the 

 milk going to the creamery was about one-half a per cent higher than he 

 had been in the habit of getting at that place; he therefore asked the stu- 

 dent to test the can of herd milk each day just before it was sent to the 

 creamery. This was done and the farm test was always higher than had 

 been received at the factory for several months. Neither the student nor 

 the owner of the herd could explain the difference so the matter was taken 

 to the creamery for investigation. 



A search for an explanation was diligently and honestly made by all 

 parties concerned, many arguments and experiments were pro- 

 posed but without going into details about them we will give 

 the final result of the evidence obtained. It seems that the 

 custom of this butter maker was to test each patron's milk in 

 the same test bottle every week. The creamery was so steady 

 going that there were few changes in the number of patrons and few test 

 bottles were broken so this practice could easily be carried out without 

 any disturbance in the routine work. Such a system of doing the work, 

 however, proved to be the cause of the low test always coming on one man; 

 the investigation showed that the test bottle which had been used con- 

 stantly to test the milk coming from the farm where the student was 

 testing, was not correctly graduated and the results it gave were always 

 aboue one-half a per cent too low. The unusual practice of the butter 

 maker to test each patron's milk in the same test bottle was therefore the 

 cause of all the trouble; the defective bottle always cheated the same man. 



After making this discovery the patron began to figure how much he 

 had lost by this deal as it was a clear case of failure to get pay for one- 

 half pound of fat for every hundred pounds of milk which had been tested 

 by that bottle. A few calculations were made and the damage done by the 

 defective bottle was settled for $25.00 by the owner of the creamery. 



This little experience shows three things: first, that all test bottles 

 ought to be carefully examined and the graduations tested before the bottle 

 is used; second, that although tests may be incorrect the maker of them 

 is sometimes innocent of his error; and third, and every man who sells 

 milk ought to have aBabcock tester and he ought to use it. 



FARM SEPARATORS. 



There is another machine that is now being extensively bought by 

 farmers who own cows. The hand separator is just now having a marked 

 effect on dairying and in some localities it is the cause of radical changes 

 in the equipment and in the product of many creameries. This change in 



