162 THE FARMER'S 



ed with great care against the inclemency of the 

 season. In the winter too, acid or fermented food 

 cannot so well be procured for them, as the low 

 temperature of the air will stop fermentation, if 

 not freeze the wash under ordinary circumstances. 

 The food fpr swine may be fermented by being kept 

 in an apartment kept at near summer heat by a stove. 

 The wash may also be kept warm by steam introdu- 

 ced according to Rumford's plan. But heating 

 liquids by steam is not so easy a process as would 

 seem at the first thought. There must be a large 

 ■j^that is large in proportion to the quantityof liquid 

 to be warmed] knd strong boiler, with two safety 

 valves, one opening outwards to let out the steam 

 if by the sudden icrease of heat, it should acquire 

 so much elasticity as to endanger the bursting of 

 the boiler; and one valve opening inwards to pre- 

 vent the sides of the boiler from being collapsed, or 

 crushed inward, or the liquid fiorn being forced 

 out of the cistern through the steam tube into the 

 boiler by the weight of the atmosphere. Then 

 there must be steam tubes rising some height above 

 the surface of the wash in the cistern, and de- 

 scending, vertically, tonear its bottom. The steam 

 must be so elastic as to overcome not only the 

 pressure of the atmosphere, but also the additional 

 pressure of that part of the liquid in the vessel, 

 containing the wash, which lies above the opening 

 or end of the tufe where the steam is discharged 

 into the vessel. 



Various means may be used to give the wa^ 

 a temperature conducive to fermentation. Water- 

 tight tubes filled with hot air, from a furnace or a 

 stove, might answer the purpose by being carried 

 thro' the cistern containing the wash to bd ferinen- 



