59 



and the inner cylinder of heavy tinned steel plate or tinned 

 copper. There is a space of one inch between the two. The 

 water connection is at E, above which connection may be 

 made with both the regular water supply and an ice water 

 tank. Steam connection is made at A w r ith a jet at C, which 

 heats the water in the circulating pipes, GGGG, and in the 

 space between the drums, the flow being upward through 

 a check valve at D. An overflow escape is provided at R. At 

 T L there is a cotton cup connected with the inner cylinder 

 by an air pipe which allows steam and gas from the milk to 

 escape. Y is an air vent open while filling the water space. 

 The temperature of the milk is taken by a thermometer M in 

 the cover V, and that of the water in the jacket at S. Inside 

 the inner drum is a curved breaker, which stirs the milk or 

 cream and thoroughly mixes it. When cooling, the cold 

 water is turned on and passes directly into the space between 

 the drums as the check valve at D prevents it from getting in- 

 to the pipes G. The pulley F revolving at 60 to 90 revolutions 

 will make the drum revolve 10 to 15 times per minute. The 

 outlet pipe N is put on at P when ready to draw the milk off 

 as is the lever Z on the cock, which is so constructed that it 

 may be easily taken apart for cleaning. 



It is claimed that with water at 150 and the milk at 

 130, the temperature in the latter will rise showly to 140 

 after shutting off the steam, and that it may be cooled in 

 30 to 35 minutes on the large machines and 20 minutes in 

 the small ones, but it is not stated what temperature the 

 water must be to do this nor the flow. It is made with a 

 capacity of from 400 Ibs. to 2,000 Ibs., at prices from $125 up 

 to $250. If cooling by circulating brine is desired the inner 

 cylinder must be made of copper and an extra charge is 

 made. 



Of all tank pasteurizers this seems to have gained the 

 most favor, and at Madison Dairy School they seemed very 

 much pleased with it, but I cannot say that I like the auto- 

 matic vent T L, because it seems to me to be difficult to 

 keep clean, and it would be a small matter to have a simpler 

 vent and let the operator open it now and then. 



Bitter (Germany), who also condemns all continuous ap- 

 paratuses, constructed a small one where a dasher revolved 

 between two steam coils in a round tank. It is evident that 

 the keeping of these coils clean must relegate this apparatus 

 to the museums as impracticable. 



