126 Morey on. Heat and Light. 
and furnishes a constant and almost perfectly regular sup- 
ply ; so much so, that while evaporating the pitch pine or 
other substances for the light, it is hardly possible some- 
times to perceive any variation for hours. 
The cylinder for holding the pitch pine or other sub- 
stance, is placed within or surrounds this. I find the best 
mode of letting out the vapor, is from a circular tube, on 
the principle of Argand’s lamp ; sometimes, when much 
light is required, from a cluster of them; and to furnish 
them with fresh, and very hot air, by a tube passing down 
and through the ignited coal and grate. This very hot air 
tends much to preserve the temperature of the vapor until 
inflamed ; and to increase the bulk of the flame, as well as . 
its intensity. ‘This tube requires a register also. And this 
kind of lamp, or lamp-stove, admits of a glass burner or flue, 
as conveniently as any other. 
It will easily be seen, that thin sheet-iron on this plan, 
will give as regular and as durable a heat, as brick or stone 
of any thickness. If instead of putting in ignited coals at 
the bottom, two or three inches of them are placed on the 
top, the red heat of the coal passes down through the whole 
in a few minutes, leaving the coal black above, just as fast 
as it is ignited below, until it reaches the bottom, when it 
becomes stationary. After this process, there is no smoke 
from the coal, even if there was before. 
We can burn in this kind of stove or lamp, (which may 
be at the same time, for aught I see, extended to warming 
and cooking, as well as to the lighting of houses, manufac- 
tories, &c.) charcoal partially saturated with water or not; 
or the steam may be furnished by a small tin plate, or other 
boiler, receiving its heat from the stove, and directing the 
steam to or near the bottom of the tar, &c.: tar, rosin, rough 
turpentine, or the spirit, or alcohol, or any kind of oil, fat, 
or tallow; mineral coal, pitch-pine wood, and the knots, 
birch bark, pumpkin, sun-flower, flax, and other seeds; as 
well as many other substances: the result is, a pleasant or 
intense white flame, free from smoke. That substance 
which nature has the most generally distributed over the 
earth, and which too is the cheapest known or used for 
affording light, appears to be the best adapted for burning 
in these lamps: for it is equally safe, easiest managed, 
evaporates at a lower temperature, consumes a greater pro- 
