3 1 8 On the Construction of Kitchen 



burning fuel, and is decomposed by it in the process of 

 combustion, contributes any thing to the heat generated ; 

 and that all the rest of the air that finds its way into and 

 through a fire-place is a thief that steals heat, and flies 

 away with it up the chimney." 



The draught occasioned by a fire in a closed fire-place 

 being into the chimney and not into the fire, cold air 

 is as much disposed to rush in over the fire as through 

 it ; and it violently forces its way into the hot fire-place 

 by every aperture, even after all the fuel is consumed, 

 carrying the heat away with it up the chimney and into 

 the atmosphere. It even makes its way between the 

 bars of the grate whenever they are not quite covered 

 with burning fuel ; hence it appears how necessary it 

 is to make the grate of a closed fire-place small, and 

 to give to that part of the fire-place which is destined 

 for holding the fuel the form of an inverted truncated 

 cone or pyramid, or else to make it very deep in pro- 

 portion to its length and width. 



But the prevention of the air from finding its way 

 through the fire-place without coming into contact with 

 the burning fuel is not the only advantage that is de- 

 rived from constructing closed fire-places in the manner 

 here recommended : it serves also to increase the in- 

 tensity of the heat in that part of the fire-place which 

 contains the fuel, which tends very powerfully to render 

 the combustion of the fuel complete, and consequently 

 to augment the quantity of heat generated in that 

 process. 



To prevent the bottom of the oven (or boiler) from 

 being too much affected by this intense heat, nothing 

 more is necessapy than to make the fire-place sufficiently 

 small, and to place it at a sufficient distance below the 



