THE LACTOMETER. 



211 



No cow should be admitted to a herd kept for butter- 

 making without knowing her qualities in this respect. 

 Many would find, on examination, that some of their 

 cows, though giving a good quantity, were compara- 

 tively worthless to them. Such was the experience of 

 John Holbert, of Chemung, New York, who, in his 

 statement to the state agricultural society, says: "I 

 find, by churning the milk of each cow separately, that 

 one of my best cows will make as much butter as three 

 of my poorest, giving the same quantity of milk. I have 

 kept a dairy for twenty years, but I never until the 

 past season knew that there was so much difference in 

 cows." 



Fig. 72. Lactometer. 



The simplest form of the lactometer is a series of 

 graduated glass tubes (Fig. 72), or vials, of equal diam- 

 eter; generally a third of an inch inside, and about 

 eleven inches long. The tubes are filled to an equal 

 height, each one with the milk of a different cow, and 

 allowed to stand for the cream to rise. The difference 

 in thickness of the column of cream will be very per- 

 ceptible, and it will be greater than most people imag- 

 ine. The effect of different kinds of food for the pro- 

 duction of butter may be studied in the same way. 



