. 32 



usually expressed in Quevenne degrees. 1 A slight 

 meniscus will obscure the surface line, and it is necessary 

 to estimate its depth. This will cause no error if it is 

 remembered that the point to be read is at the surface of 

 the milk and not at the top of the meniscus. 



A type of lactometer known as the New York board of 

 health lactometer is in somewhat general use. The scale 

 of this instrument does not give the specific gravity di- 

 rectly, but is so arranged that milk having a specific gravity 

 of 1.029 (at 60 F.) will read 100. As the zero mark is the 

 point to which it will sink when immersed in pure water, 

 100 on the scale corresponds to 29 on the Quevenne scale. 

 New York board of health lactometer degree may be con- 

 verted into Quevenne degrees by multiplying by 0.29. 



CALCULATING TOTAL SOLIDS BY FORMULA. 



When the percentage of fat and the specific gravity of the 

 milk are known and only the closely approximate percent- 

 age of total solids is wanted, it should be calculated by the 

 Babcock formula. The following table and directions for- 

 using it are taken from Bureau of Animal Industry Bulletin 

 134: 



1 Quevenne degrees are converted into specific gravity by dividing by 

 1,000 and then adding 1 to the quotient. This is done at a glance. For 

 example, if the Quevenne reading is 32.5, the specific gravity is 1.0325. 



