500 Of the Management of Fires 



must be placed very near the surface of the burning 

 coals, otherwise so much more cold air than is wanted 

 will find its way into the fire-place and mix with the 

 flame that the bottom of the boiler cannot fail to be 

 sensibly cooled by it. 



When a boiler is properly set, if a fire of a moderate 

 size that burns well does not heat it in a reasonable 

 time, the fault must necessarily lie in the bad manage- 

 ment of the doors and registers of the fire-place ; for, 

 as the heat required to heat the boiler is a certain 

 quantity^ which cannot vary, if the boiler is not found 

 to be heated as fast as it ought to be by the quantity 

 of fuel consumed, a part of the heat generated must 

 necessarily go to heat something else; and there is 

 nothing at hand that can take it, except it be the cold 

 air of the atmosphere, which, whenever it is permitted 

 to enter a fire-place in an improper manner or in too 

 large quantities, never fails to rob it of a great deal of 

 heat, which it takes with it up the chimney, as has 

 already been observed. 



If the door by which the fuel is introduced into the 

 closed fire-place of a kitchen boiler is not kept con- 

 stantly closed, it is quite impossible that a well-con- 

 structed fire-place can answer. With such neglectful 

 management, a bad fire-place is certainly preferable to 

 a good one ; for, when an enormous quantity of fuel is 

 consumed under a boiler, some part of it must neces- 

 sarily find its way into it, even if, instead of being set in 

 brick-work, it were suspended over the fire in the open 

 air; but, when a fire-place is made no larger than is 

 necessary in order to heat the boiler in a proper time 

 when the door of the fire-place is kept closed, it is not 

 surprising that the boiler should be much slower in 



