95 



inches high, holding 40 tbs. 

 each, as may be needed. Place 

 them in an oblong boiler 

 (Fig. 98), made to order if 

 necessary. Get a suitable 

 tank for cooling, and a stirrer 

 (see Fig. 98.) That is all 

 there is required. 

 Fig. 98. I acknowledge, however, 



that if money and steam is at command, it is less work to 

 use some special apparatus than to keep four or five cans 

 stirred by hand, yet part of this gain is counterbalanced by 

 the increased labor in keeping the apparatus clean. 



Stir the milk continuously until it is 140 or whatever 

 higher temperature that may be decided on, and see to it that 

 when it has reached that temperature the water in the boiler- 

 is only a degree or two higher. 



If it should be higher, reduce it by adding cold water. 

 Place the boiler where the temperature will remain station- 

 ary for 20 to 30 minutes and cover the milk can. 



Meanwhile, have a tub filled with cold water, preferably 

 with ice water, and place the milk can in it. Moving the 

 can round with one hand (so as to stir the water), the milk 

 is stirred with the other hand until at least 50 cold. 



Where there is a tank with flowing cold water, it is 

 enough to stir the milk, but where neither this nor ice are at 

 hand, the quantity of water must be regulated according to 

 its temperature. 



If, as for instance, there are 20 Ibs. of milk at 155 that 

 we desire to cool to 60 (50 would be better), we have to cool 

 20 Ibs. 95 or 1900 units. 



Supposing then we have water at our command at 48; 

 then we must theoretically have 158 J Ibs. of this water to 

 reduce the milk to 60, but practically this is not enough and 

 it would be too slow work, hence I consider that 300 Ibs. of 

 such water would be nearer the mark. 



The best way of cooling is to run it over one of the small 

 surface coolers in a clean room. 



This question of cooling is the great stumbling block 

 which for years will prevent farmers from pasteurizing the 

 milk. Indeed, I feel inclined to make the broad assertion 

 that unless there is flowing water of not more than 48 or 



