152 Of the Management of Fire 



8 inches deep ; and under its bottom, which is quite flat, 

 there is a thin spiral projection, which was cast with the 

 pot, and serves instead of feet to it, the turns of which, 

 when the pot is set down on a flat surface, form a spiral 

 flue in which the flame circulates under the bottom of 

 the pot. This projection, which is near half an inch 

 thick where it is united with the bottom of the pot, and 

 less than a quarter of an inch below where its lower 

 edge rests on the ground, is about 4 inches wide, or 

 rather deep. This projection was made tapering, in 

 order to its being more easily cast. To defend the out- 

 side of this pot from the cold air, the pot is enclosed in 

 a cylinder of thin sheet iron, equal in diameter to the 

 extreme width of the pot at its brim, just as high as the 

 depth of the pot and of its spiral flues taken together. 

 The pot is fastened to this cylindrical case by being 

 driven into it with force, a rim in the form of a flat hoop, 

 about an inch and a half deep and a little tapering, being 

 cast on the outside of the pot at its brim, the external 

 surface of which was fitted exactly into the top of this 

 cylinder. This projection is useful, not only in uniting 

 the pot to its cylindrical case, but also to keep this cyl- 

 indrical ' case at some small distance from the sides of 

 the pot, by which means the heat is more effectually 

 confined. 



To be able to move about this pot from place to place, 

 it has two handles which are riveted to the outside of 

 its cylindrical case ; and it is provided with a wooden 

 cover. 



I am sensible that I often expose myself to criticism 

 by anticipating what would more naturally find its place 

 elsewhere. But what I have here said in regard to this 

 iron pot is intended merely as hints to awaken the 



