45 - 



which, is made by von Schmidt. 

 in Bretten. 



Another late German adop- 

 tion of cover is show in Fig. 46, 

 and indeed there is hardly a cool- 

 er made where the air may not 

 be kept out sufficiently for all 

 practical purposes. 



The French heater by Hig- 

 net, mentioned on page 24, is of 

 course equally well adapted for 

 cooling. 



CENTRIFUGAL COOLERS. 



THE BERGDORFER Ma- 



chine works make a cream cooler 

 illustrated in Fig. 47. It con- 

 sists of an inverted cone of cast 

 iron in which revolves a similar 



shaped drum driven by P. The cream enters the lower bearing of 



the drum and escapes through the perforated upper part of the drum 



into the gutter and leaves at OR. 



The water enters at w and leaves through the siphon o. 



The cream is here, as in the centrifugal heaters, spread in a thin 



film over the drum. The speed given is 600 revolutions per minute. 

 If the friction of the water be not a too great objection to this 



system in larger apparatus, it seems to me there are great possibilities 



in developing this idea. I have thus suggested that the drum be ro- 



tated by aid of the 



cooling water. It may 



also be used for ele- 



vator, as indeed it is 



in Fig. 47. 



ICE COOLERS. 



Where water is 

 scarce and ice plenty 

 the cream cooler orig- 

 inally designed by 

 Prof. Fjord, Fig. 48, Fig. 46. 



