CONSTRUCTION OF IIOT-HOfSES. 283 



tieiits have liajipened by furnaces havino- been thrust 

 into the house; besides, too powerful a heat is there- 

 by excited at one place. 



It has been argued, that such a flue as the above 

 is too shallow; that it would often require sweeping, 

 there being so little room to hold soot. But the in- 

 tention is to burn nothing but charcoal or cinders, 

 as mentioned above; so that very little soot will ac- 

 cumulate, and sweeping oftener than once a-year 

 will seldom be found necessary. Even peat, mixed 

 half with cinders, make very little soot. But small 

 coals, uncharred, should not be used, as they give 

 out too much smoke, and too little heat. 



I come now to the consideration of the air-fuic. 

 These flues, in my opinion, in the ordinary manner 

 in which they are constructed, notwithstanding the 

 encomiums bestowed upon them by certain theo- 

 rists, are quite useless in the hot-house. The idea 

 of collecting the heated air about a furnace, and 

 conducting it to the cold end of the house, is just, 

 and natural enough. But if this cannot be done, 

 Arithout conducting the tube or flue that shall con- 

 vey it, upon the Are flue, to the evident loss of its 

 surface, and of its best part, 1 would ask, what is 

 gained by the experiment ? or rather, what is lost 

 by it? Evidently a great deal; all the expense, and 

 double the quantity of heat that can be thus con- 

 veyed. The fact is, there is no heat comes to the 

 far end of the house, but just what is collected from 

 the flre-flue into the air-flue, as it travels along. 

 None of it comes from the furnace. 



