109 
Description of a Stove. 
geous for renewing the respirable air of the apartment, 
and prevents the danger of currents of cold air attracted 
by the fire ; and which is necessary, as I have observed, 
whenever the volume of air in the apartment is not suffi- 
cient, to supply both the consumption of the fire, and the 
circulation in the heat pipes. 
Fig. 2. is a plan of the foundation of the hearth at the 
height of the line A B, fig. 1. 1 1 are empty spaces, to re- 
ceive the air, and convey it into the compartments; where 
it is to be heated before it issues by the heat openings, 
whether the air be obtained from without, or simply by 
the apertures m m, fig. 1. 
Fig. 3. pi. 4. plan at the height of the line C B, fig. 1 ; 
that above the door of the fire-place, nn nn are the dou- 
ble plates of cast iron, forming the compartments in which 
the air is to receive the effect of the heat of the fire. 
o o The empty space between these plates. 
Fig. 4. Front section at the line I K, fig. 3. The ar- 
rows indicate the direction of the smoke in the circulatory 
pipes of the front part.^ 
In this the plates of iron n n are seen in their perpen- 
dicular situation, with the tongues which form their com- 
partments on each side of the fire-place. One of these 
plates is represented in front fig. 7. 
T is an opening left at the bottom of the fourth circu- 
latory pipe, to restore the draught of air in the fire-place, 
if necessary, by burning there a few slips' of paper, or 
other light combustible ; I say if necessary , because I 
have found by experience, that this precaution may be 
* Among 1 the number of Swedish stoves described and delineated in the col- 
lection published by baron Cronstedt there are several, the circulating pipes of 
which pass under the hearth. This gives them a little more extent no doubt, 
but as soon as the hearth is covered with ashes, the air passing beneath can re- 
ceive but a very slight impression of heat ; it obliges the fire-place to be raised 
higher ; and it renders the construction more complex and expensive. For 
these reasons I have adopted the most simple plan. 
