MAKING BUTTER 329 



EXERCISE. Who has seen and can describe a cream separator? 

 Obtain two small clean bottles of the same size and shape and fill both 

 with milk as soon as it comes from the cow. Shake one of them about 

 every half hour. Leave the other perfectly still. On which does the 

 cream rise best ? Another day fill one of the these same bottles with 

 the milk first drawn from the udder and the other with strippings. 

 After the cream rises, try to estimate how much more cream there is in 

 strippings. 



NOTE TO THE TEACHER. Ask the pupils to take the temperature of 

 the well or spring water at home and of the contents of the churn. Could 

 a can of milk be kept advantageously in water of this temperature? 

 Would such water chill and harden butter? Ask for experiences in 

 churning when the butter would not come. What were the condi- 

 tions? 



OPTIONAL PROBLEMS IN DAIRYING. (i) In one year cow \ gives 

 4000 pounds of milk and cow B gives 5000 pounds ; the Babcock test 

 shows that A's milk contains 4.5 per cent of butter fat and B's milk 3.5 

 per cent ; how many pounds of butter fat are pro'duced by each in a 

 year? 



(2) Assuming that one pound of butter fat is mixed with enough 

 water, curd, and salt to make i pounds of butter, what is the number 

 of pounds of butter produced annually by each cow? What is the 

 value of the yearly butter product of each cow, with butter at 25 cents 

 per pound ? 



(3) How many more pounds of butter fat would cow A produce in a 

 year (see problem i) if the cream from her milk were separated in a 

 cream separator than if it were raised in shallow pans, assuming that 

 there is left in the skim milk from the separator -fa of the fat in the 

 whole milk and in the skimmed milk of the fat that was present in 

 the whole milk? 



(4) What would be the value of this increased production of butter 

 fat in problem 3, at 25 cents per pound of butter, assuming that each 

 pound of butter fat would make I x pounds of butter ? 



(5) Use the answer to problem 4 to determine how many months or 

 years it would require for the extra amount 01 butter made by the sepa- 

 rator from a herd of 6 cows like A to pay for a small hand-power 

 separator costing $75. Can any one point out an additional saving (in 

 feeding the calves) when a separator is used ? 



