112 
Description of a Stove . 
soft enough to admit of being bored, so as to rivet on bent 
slips of plate iron, which would perfectly answer the 
purpose of the tongues and grooves. As these would ne- 
ver be exposed to the action of the dame, there is no rea- 
son to fear their casting. The latter of these two me- 
thods is obviously the most advantageous, as it occupies 
less room, and yet affords more surface to receive the ac- 
tion of the heat, and communicate it to the circulating 
air. 
In concluding my description of this stove I ought not 
to omit saying, that nearly two years experience has con- 
vinced me of the good effects of its proportions. 
It is placed in a room fronting the north, the door of 
which measures 47 metres square (about 12 toises |) and 
which is 42.5 decimetres (13 feet) high. 
Every day a log of wood 28 or 30 centimetres (10 or 
11 inches) round, sawn into three pieces, or an equal 
quantity of smaller wood, is burned in it at once. The 
slider of the door of the fire-place is shut, and the key 
R, fig. 6, is turned, as soon as the wood is reduced to 
charcoal. Ten hours after the air throughout the room 
is at a temperature above the mean ; and the centigrade 
thermometer, placed 38 centimetres (above 13 inches) 
from the stove, rises rapidly to 16 or 17 degrees. 
To shew still more plainly to what degree the economy 
of fuel and preservation of heat may be carried by this 
construction, I shall relate another experiment, which I 
have repeated on several occasions, and which has al- 
ways afforded me very nearly the same results. 
The thermometer in the room, in which there was no 
fire the day before, being between 9 and 10 degrees, a 
log sawn in three as usual was put into the fire-place 
about eleven in the morning ; and at three in the after- 
noon a similar quantity of fuel was put in. 
