10 ON THE HEAT EVOLVED 



rests, as will be seen, by referring to the enlarged sectional 

 view on the plate, Fig. 2. Three inches above this chamber 

 is another, closely fitted within the body of the stove, and per- 

 forated with holes one quarter of an inch in diameter. The 

 interior of the body of the stove above, is made to assume the 

 conical shape which it presents, with the apex downwards, by 

 coating it with fire clay, so as to expose only one and a half 

 inches diameter of the surface of the chamber, and on which 

 the fuel rests. The space between the chambers is necessary 

 in experimenting on anthracite coals in small quantities, for 

 the purpose of heating the air as much as possible before it 

 comes in contact with the burning body, and the clay coating 

 is also necessary in the same experiments, to act as a non-con- 

 ductor. The stove, Fig. 1., is supplied with air through aper- 

 tures just above the ash pit, or lower door, and to lessen, or 

 close these apertures, a sliding sheet iron hoop, (not shown in 

 the engraving,) is fitted with great accuracy. The middle 

 door is necessary, to obtain access to the upper chamber when 

 its apertures require clearing, during an experiment. For 

 heating water, a tin vessel in the shape of a crescent, rests on 

 cleats, between the upper and middle doors. This vessel is 

 accurately fitted to the body of the stove, but may be removed 

 to any required distance, at pleasure ; and we may thereby 

 lessen the evaporation of the water, its object being to regu- 

 late the hygrometric state of the air. 



All the doors of the stove are represented as open. The upper 

 door is to admit the fuel. The cone, leading from the body 

 of the stove to the pipe, is ten inches long, and very accurately 

 fitted to the former, but removable for the purpose of separat- 

 ing them, to take from the stove and ash pit, the unconsumed 

 parts of any body, that may have been experimented upon. 

 This is done with facility, as the pipe is supported from the 

 ceiling, by wires which sustain it in its place, after the body 

 of the stove is removed. 



In the cone, three quarters of an inch above its junction 

 with the body of the stove, (which in this place is mftde flat,) 

 is an aperture one inch broad, and one and a quarter inches' 



