27 



the bottom into the outer can and thence out to the second set of 

 cans through M. Both are set in a tank of water which, together with 

 the water w in A, is heated by a jet of steam. 



The Creamery Package Mfg. Co. has changed this plan some- 

 what, and just finished a large apparatus, with six set of large cans, 

 arranged in a tank one below the other. It is intended for the cream- 

 ery of Mr. Wood, and supposed to pasteurize the milk fast enough 

 for two or three Alpha separators. 



Mr. Lawson, of Grinnel, uses a similar but simpler device, as he 

 lets the milk down through an outside pipe, something like the inlet 

 to Fjord's heater, into a single can from which it runs into the cooler. 

 The can and pipe is placed in a barrel with boiling water (direct 

 steam). 



As cooler he uses something like the cream cooler sold by F. B 

 Fargo, with a tube soldered to the inside of the can which he places 

 in a barrel with crushed ice and salt. It is possible to pasteurize 

 the cream from one separator with one such heater and two coolers. 

 Though of no practical value I illustrate in Fig. 23 a heater made 

 as early as 1887, by G. Reiiisch, of Breslau. 



It consists of a steam 

 chamber (5), and a milk 

 chamber (6), which has a 

 high rim ( 7 ) to prevent foam- 

 ing over. The milk enters at 

 (3) and leaves at (4). Not 

 being stirred it seems to me 

 that a direct current from 3 

 to 4 would soon be established. 

 The proportionate heating 

 surface is also too small. 



IF 



Fig. 23. 



TANK HEATERS. 



To all the "continuous" heaters, the bacteriologists object as 

 before said because even with a large body of milk in transit there 

 is no assurance that all the milk has been exposed to the high tem- 

 perature for the time needed. 



On this principle Prof. Russell of Madison, Wis., constructed an 

 apparatus illustrated in Figs. 24, 25 and 26, which he calls a " com- 

 bined pasteurizer and cooler;" this is a misnomer, it is a "pasteur- 



