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ON THE CONSTRUCTION AND HEATING OF HOT-HOUSES, 
ages past been a desideratum with the British public, and the attention of the 
legislature has for some time been directed to this desirable object. It was, no 
doubt, the principle of combustion laid down by Scheele, Priestley, Lavoisier, and 
Cavendish, that led to the practice of throwing an excess of atmospheric air into 
the furnace, to produce this effect ; but it has always been attended with a great 
increase of fuel^ and still remains but partial and very imperfect. 
2 
In all the common methods of burning coal, a variety of gases, both inflammable 
