ii4 GUIDE TO DAIRYING IN SOUTH AFRICA 



this country. The best method to employ, especially 

 with natives, is to use a simple little instrument 

 called a metronome, shown in Fig. 12. 



SPEED TRIAL. TABLE No. I. 



This can easily be adjusted to suit the speed 

 of any machine, and the pendulum, which merely 

 swings backwards and forwards, acts as a guide to 

 the native working the separator; in fact, if the 

 metronome is correctly set, and the handle of the 

 machine is turned exactly in time with the swing- 

 ing of the pendulum, then, and then only, can the 

 cream suppliers safely say that the speed of their 

 separators has been correctly maintained. It is 

 always advisable to work a separator at the speed 

 recommended by the makers, or if anything 3 to 

 5 % higher rather than lower. The only time when 

 it is permissible to reduce the speed of any machine 

 is when the feed tin is partially empty. This, how- 

 ever, can easily be regulated by watching the cream 

 as it leaves the cream spout. If this turns in under 



