108 LESSONS IN AGRICULTURE 



thoroughly mixed. Take about a half cupful as a sam- 

 ple and put it into a clean bottle. From this bottle the 

 sample is drawn for testing, after mixing the contents 

 of the bottle thoroughly. 



Having determined the per cent of butter-fat in the 

 sample, an estimate can be made of the total amount 

 of butter-fat in a gallon of milk. (A gallon weighs 

 8 14 pounds.) 



Make many tests of the same cow's milk to determine 

 its richness. A pound of butter-fat should make, in 

 ordinary practice, about 1.1 pounds of butter, and the 

 pupils can compare the price paid for butter and for 

 the butter-fat, if sold at the creameries, and determine 

 which method of sale is better. 



If the school is in a dairy district, this lesson will 

 furnish work for several weeks, and be profitable to 

 patrons as well as to pupils. 



Free Bulletins, U. S. Dept. of Agriculture 

 Farmers' Bulletins. 



No. 29. Souring of Milk and Other Changes in Milk 

 Products. 



No. 42. Facts about Milk. 



No. 55. The Dairy Herd: Its Formation and Management. 



No. 57. Butter Making on the Farm. 



No. 63. Care of Milk on the Farm. 



No. 151. Dairying in the South. 



No. 166. Cheese Making on the Farm. 



No. 201. The Cream Separator on Western Farms. 



Problems 



1. How many pounds of butter-fat in 5,000 pounds 

 of milk that tests 4 per centt 



2. A farmer owns a herd of 15 cows that average 

 24 pounds of milk per head daily. How many pounds 

 of milk does he get in six months (thirty days each) ? 



