Improvement of Missouri Herds. 



375 



machine must ahvays be made to balance. In case there is only one 

 sample to be tested, a bottle of water may be used for a balance. 



Fifth — Start the machine slowly, gradually increasing the 

 speed until the test bottles are whirling at a rate of 1,000 to 

 1,200 revolutions per minute. (By counting the number of revo- 

 lutions made by the pockets for each turn of the crank it can be 

 easily calculated how many turns of the crank will be necessary 

 to achieve the required speed.) Turn steadily for five minutes, 

 then gently stop the machine, and with the pipette carefully, in 

 order that no bottle be run over, add clean, soft hot water into 

 the test bottle until the water and fat rise two-thirds of the way 

 up the neck of the bottle, then close the lid, and whirl as before for 

 a period of two minutes. Now the test is made, and simply re- 

 quires reading. 



Showing how to read the test. Spread the dividers from the extreme bottom to the 

 extreme top of the fat, then place the lower point at O and read the number at the top 

 point. 4.6 fat in this case. 



Sixth — With a sample compass or dividers measure the fat 

 in the neck of the test bottle, as shown in figure 23. The points 

 of the comipass should extend from the very bottom to the very 

 top of the fat, as shown in the cut. Read the fat while hot, or if 

 it gets cool warm it up to about 130 or 135 Fahr. before reading. 

 Do not count out anything for the little cup or maniscus on the 

 top of the fat, Being careful not to change the spread of the 



