56 



a faucet for emptying the last milk and F is outlet for ex- 

 haust steam and I is outlet for condensed water. The price 

 for both with a capacity of 6,000 to 8,000 fibs, per hour is about 

 $812 f. o. b. Berlin. It is claimed to be easy to clean. As far 

 as the incomplete description goes it seems that there are 

 two cylinders inside the drum and that one is revolving while 

 the milk goes between them, first up, then down and then up 

 again. 



TANK HEATERS. 



To all the "continuous" heaters, the bacteriologists ob- 

 ject as before said because even a large body of milk in 

 transit there is no assurance that all the milk has been ex- 

 posed to the high temperature for the time needed. 



On this principle Prof. Russell, of Madison, Wis., con- 

 structed an apparatus illustrated in Figs. 24, 25 and 26, which 

 he calls a "combined pasteurizer and cooler;" this is a misno 

 mer, it is a "pasteurizer;" if it were not designed to cool as well 

 as heat it would simply be a heater. I point this out as there 

 is a tendency to call the simple heating of the milk pasteuriz- 

 ing; this is wrong, pasteurizing is both heating and cooling. 



Fig. 57. 



Fig. 57 Diagrammatic side view of pasteurizer i. v. in- 

 side vat for milk; s. c. stop-cock in outlet tube; ni. o. milk 

 outlet; 1. lever to control stop-cock; o. v. outside vat; w. 

 c. water chamber; w. p.. water pipe (steam or water); ther. 

 thermometer in milk chamber; r. brass rod to which i. s. 

 (inside stirrers) in milk chamber are attached; r. rod to 



