216 ELEMENTS OF FARM PRACTICE 



problem is solved as follows: .04 x 175 lbs. = 7, the number 

 of pounds of fat. 



Cream is not pure butter-fat; so it must be tested also. 



Questions: 



1. Why was some device for testing milk badly needed? 



2. Who invented such a device? 



3. Upon what principles does it work? 



4. If you have seen testing done at the creamery, describe it 

 as best you can. 



5. What is meant by per cent of fat in milk? 

 Arithmetic: 



1. A hauls 230 lbs. of milk to the creamery. It tests 3.5% fat. 

 How many pounds of butter-fat does it contain? .How much is the 

 butter-fat worth at 31c. per lb. 



2. B hauls 150 lbs. of milk to the creamery. It tests 4.5% fat. 

 How many pounds of fat does it contain? How much is the fat worth 

 at 34c. per lb.? 



3. C delivers 75 lbs. of cream to the creamery. It tests 24% 

 fat. How many pounds fat has he? What is it worth at 34c. per lb.? 



TESTING COWS 



Culling. — Now that dairying is getting to be such an 

 important part of farming, farmers are studying how they 

 may secure greater profits. They have found that, if they 

 are to realize satisfactory returns on dairying, they must 

 keep only cows that are capable of producing large amounts 

 of milk and butter-fat. They have found also that the only 

 way to know just what each cow is doing is to weigh the milk. 

 At first this work seemed unnecessary, but now nearly every 

 good dairyman tests his cows and finds that it pays him to 

 do so, because it takes less time than to milk one or two 

 unprofitable ones. 



Weighing Milk. — This is very simple, if one has a spring 

 balance hung in the barn near the milk can, and a sheet 

 of paper with a column for each cow, tacked up nearbj^ so 

 that the results can be jotted down as the milk is weighed. 

 It is not necessary to weigh the milk every day. Weighing 

 it night and morning, once every ten days, or even once a 

 month, makes it possible to determine quite accurately the 

 amount of milk a cow has given for the month. 



Advantages of Weighing Milk Every Day. — There are a 

 great many advantages, though, in weighing milk every 

 day. By so doing one knows accurately how much milk a 



