122 FARMING ON FACTORY LINES 



knowledge, we can control the amount of heat in a 

 stack. Many farmers who follow the practice of hay 

 sweating know from long experience how much heat 

 is desirable. Their method is largely guesswork, and 

 wherever in farm work we can dispense with guess- 

 work, the better. 



Thermometers are cheap enough, and should 

 always be used in stack building. In building a 

 stack, put a long iron pipe in the centre and build 

 around it. Then place the thermometer in this pipe 

 and, by the assistance of a piece of graduated cord, 

 the heat at any part of the stack can be determined. 

 A good maximum temperature to get the stack to is 

 120° F., which means that if a piece of iron be thrust 

 into the stack and left about ten minutes, the iron on 

 being withdrawn is so hot that it cannot be borne on 

 the back of the hand. 



HEATING IN PIKES 



Slight heating will, of course, take place in pikes, 

 and when this is on the decline (judged by an iron 

 bar) the hay stacking may commence. 



If heating in a pike takes place through moisture, 

 that is damp heating, the pikes should be spread out, 

 dried a little more, and re-made before stacking, 

 otherwise they won't fire but turn mouldy. 



Re- heating also takes place in the stack, very slowly 

 at first and rapidly later. The following are the chief 

 points to be remembered in connection therewith: — 



First, the slower the stack is built the greater the 

 heat will become. The reason for this is that the 

 stuff is loose and a great amount of air is present. 



Well-trampling the stack also minimises the after- 

 heating, since trampling excludes air. Hence, with 

 very dry hay, slow carting seems to be indicated. In 



