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upon cooling ; consequently, the hot-air must be allowed to enter by a 

 flue, as near the roof or ceiling of the shed or house as convenient, and 

 so that only the coolest air may be exhausted. The point furthest 

 away from this, and consequently the lowest, should be the place from 

 which to exhaust the dr by means of fans. The building of course may 

 be of iiny size, but should be greater in length than in breadth, and 

 should be, as near as possible, hermetically sealed. 



" In the first place, a framework of sawn hardwood timber is 

 erected to the height of, say, 10 to 12 feet, with flooring joists set on 

 blocks 3 inches or 4 inches above the level of the ground, but not 

 boarded (open battens being the floor, which is afterwards covered with 

 coir or other matting.) Upon the roof is also placed flooring joists for 

 the ceiling, and set on the wall plates as if for a two storey building. 

 If bricks area cheaper material than galvanised iron, the whole building 

 may be made of brick, but I have found iron both cheaper and more 

 portable. 1 prefer the flat galvanised iron to the "corrugated," as it 

 does not require skilled labour to turn, rivet and solder the edges. The 

 inside only of this building is next covered with iron sides, ends, and 

 ceiling. At the angle of the ceiling it is best to turn the edges, rivet, 

 and solder, before nailing up. All other joints can be stuffed, or calk- 

 ed with hemp or cotton, even pasted over with brown paper is good. 



u The roof can either be left flat, or an ordinary shed-roof of corru- 

 gated iron. It may even be raised into a second storey, or loft, to be 

 used as a finishing room above the hot-air chamber. 



"A brick furnace is now built at one end of the shed with smoke 

 stack either of brick or iron. The furnace should be built about two 

 feet away from the end of the shed to allow of the hot-air flue (2 feet 

 inside measurement) to connect the furnace with the shed which will 

 emanate about six inches from the ceiling of the chamber and in the 

 centre. In building the furnace a double row of four inch gas pipes 

 are laid, one set of ends set in fire clay but entering the flue, and the 

 other set of ends, open to the air on the other side of the furnace. Great 

 care must be taken that neither fire nor smoke is allowed to enter the 

 flue direct from the furnace, and the pipes, or tubes should never be 

 allowed to get red-hot, or they are liable to burn, or crack. Now,at the 

 other end of the shed, a trench should be dug in the ground, below the 

 flooring of the same size as the draught capacity of the flue, and emanat- 

 ing below the wall for a few feet. Over this draught trench, either one 

 or two exhaust fans are built, and these are in my case worked by water 

 power, so that I could regulate their pace to one degree of temperature 

 night or day. 



u It will be understood that, as the air is exhausted from the chamber 

 it must necessarily pass through the heated pipes to replace the air 

 withdrawn, and that, that heated air is drawn through the matting on 

 the battened floor, and, consequently, through the crop that is spread 

 upon it, thus only the coolest and dampest air is withdrawn." 



