Transactions of the Horticultural Society. 16? 



to cover three or four acres of ground with a glass roof, as 

 it is now to cover a few square yards, a Sierra Leone orchard 

 will be a matter of no difficulty. The original expence being 

 once incurred of covering an acre, the after management, 

 excepting fuel, will be little more expensive than that of a 

 flower-garden. 



71. Directions for the Management of the Hothouse Fire-places, 

 that are constructed ix>ith Double Doors, and Ash-fit Registers. 

 By William Atkinson, Esq. F.H.S. Read April 6. 1824. 



This is a valuable practical paper, and ought to be maturely 

 studied by all those that have the care of hothouse fires. In 

 abridging it, we will endeavour to give the sense as completely 

 as possible. 



After the fire is lighted, the fire-place door should be kept 

 close, and no more air admitted by the ash-pit door than is 

 necessary to make it burn briskly, — not violently, — because 

 that increases the waste of fuel, without increasing the heat. At 

 all times the air that is necessary for blowing the fire must be 

 admitted by the ash-pit door, or register, in order that it may 

 get heated in passing through the fire to the flame. When air 

 is admitted by the fire-place door, it will generally rush over 

 the fire into the flue, without being heated, thus tending to 

 cool the flue, instead of heating it. 



When the flue is properly heated, and the fuel burned 

 nearly to redness, scarcely any air need be admitted by the 

 ash-pit door ; in most eases the fire will burn with what air gets 

 through the crevices in the iron work. The damper should 

 also be put in as far as it can be, so as only to keep the fire 

 just alive, and prevent, as much as is practicable, heat escap- 

 ing by the chimney. The object is to generate heat in the fire- 

 place, just as fast, and no faster, than it is required to be given 

 out by the flue, for maintaining the temperature of the house. 



Equal quantities of coal and small cinders keep up a steadier 

 fire than either alone. Before adding fresh fuel to the fire, 

 push that which is unconsumed towards the farther ends o. 

 the bars, and apply the fresh fuel immediately behind it, so 

 as to fill up the space close to the fire-place door. When fresh 

 fuel is thrown over the surface of a hot fire, it produces an 

 immense volume of smoke and blacks ; when added in front 

 of the fire much of the smoke given out is consumed in pass- 

 ing over the part ignited. When fuel is thrown to the further 

 end of the fire, or into the throat of the flue after the fire has 

 burnt low, and the flue is hot, " the heat of the brick work 

 distils gas out of the coals ; this gas gets into the flue, and 

 when the fuel over the fire becomes inflamed, if the flame be 



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