38 Of the Management of Fire 



ashes which occasionally fall through them into the 

 ash-pit. 



One great advantage attending fire-places on the 

 construction here proposed is, that they serve equally 

 well for every kind of fuel. Wood, pit-coal, charcoal, 

 turf, etc., may indifferently be used, and all of them 

 with the same facility, and with the same advantages ; 

 or any two, or more, of these different kinds of fuel 

 may be used at the same time without the smallest in- 

 convenience ; or the fire having been lighted with dry 

 wood, or any other very inflammable material, the heat 

 may afterwards be kept up by cheaper or more ordinary 

 fuel of a more difficult and slow combustion. Some 

 kinds of fuel will perhaps be found most advantageous 

 for making the pot boil, and others for keeping it boil- 

 ing ; and a very considerable saving will probably be 

 found to result from paying due attention to this cir- 

 cumstance. When the fire-place is so contrived as to 

 serve equally well for all kinds of fuel, this may be 

 done without the least difficulty or trouble. 



I have just shown that narrowing that part of the 

 fire-place which lies below the grate serves to make 

 the air enter the fire in a more advantageous manner. 

 This construction has another advantage, perhaps still 

 more important : the heat which is projected downwards 

 through the openings between the bars of the grate, in- 

 stead of being permitted to escape into the ash-pit (where 

 it would be lost), striking against the sides of this in- 

 verted hollow cone, it is there stopped, and afterwards 

 rises into the fire-place again with the current of air 

 which feeds the fire, or it is immediately reflected by 

 this conical surface, and, after two or three bounds from 

 side to side, is thrown up against the bottom of the 

 boiler. 



