154 



Of the Management of Fire 



To effectuate these purposes, the fuel is not mixed 

 with the limestone, but is burned in a closed fire-place, 

 which opens into one side of the kiln, some distance 

 above the bottom of it. For large lime-kilns on these 

 principles there may be several fire-places, all opening 

 into the same cone, and situated on different sides of 

 it ; which fire-places may be constructed and regulated 

 like the fire-places of the furnaces used for burning 

 porcelain. 



At the bottom of the kiln there is a door, which is 

 occasionally opened to take out the lime. 



When, in consequence of a portion of lime being 

 drawn out of the kiln, its contents settle down or 

 subside, the empty space in the upper part of the kiln, 

 which is occasioned by this subtraction of the burned 

 lime, is immediately filled up with fresh limestone. 



As soon as a portion of lime is taken away, the door 

 by which it is removed must be immediately shut, and 

 the joinings well closed with moist clay, to prevent a 

 draught of cold air through the kiln. A small opening, 

 however, must be left, for reasons which I shall presently 

 explain. 



As the fire enters the kiln at some distance from the 

 bottom of it, and as the flame rises as soon as it comes 

 into this cavity, the lower part of the kiln (that below 

 the level of the bottom of the fire-place) is occupied by 

 lime already burned ; and as this lime is intensely hot 

 when, on a portion of lime from below being removed, 

 it descends into this part of the kiln, and as the air in 

 the kiln to which it communicates its heat must rise 

 iipwards in consequence of its being heated, and pass 

 off through the top of the kiln, this lime in cooling is, 

 by this contrivance, made to assist in heating the fresh 



