20 Some new Researches on Flame. 
oil, and that of a wick fed with oil smaller than that of car-: 
buretted hydrogen; and a ring of cool wire which instantly ex- 
tinguishes the flame of carburetted hydrogen, only slightly di- 
minishes the size of a flame of sulphur of the same dimensions. - 
Where rapid currents of explosive mixtures are made to act 
upon wire-gauze, it is of course much more rapidly heated ; and 
therefore the same mesh which arrests the flames of explosive 
mixtures at rest, will suffer them to pass when in rapid motion ; 
but by zxcreasing the cooling surface by diminishing the size, or 
increasing the depth of the aperture, all lames, however rapid 
their motion, may be arrested. Precisely the same law applies 
to explosions acting in close vessels: very minute apertures when 
they are only few in number will permit explosions to pass, which 
are arrested by much larger apertures when they fill a whole 
surface. A small aperture was drilled at the bottom of a wire- 
gauze lamp in the cylindrical ring which confines the wire-gauze 5 
this; though less than ]-18th of an inch in diameter, passed the 
flame and fired the external atmosphere, in consequence of the 
whole force of the explosion of the thin stratum of the mixture 
included within the cylinder driving the flame through the aper- 
ture ; though, had the whole ring heen composed of such aper- 
tures separated by wires, it would have been perfectly safe. 
Nothing can demonstrate more decidedly than these simple 
facts and observations, that the interruption of flame by solid 
tissues permeable to light and air, depends upon no recondite or 
mysterious cause, but to their cooling powers, simply considered 
as such. é 
When a light included in a cage of wire-gauze,is introduced 
into an explosive atmosphere of fire-damp at rest, the maximum 
of heat is soon obtained; the radiating power of the wire, and 
the cooling effect of the atmosphere, more efficient from the 
mixture of inflammable air, prevent it from ever arriving at a 
temperature equal to that of dull redness. In rapid currents of 
explosive mixtures of fire-damp, which heat common gauze to a 
higher temperature, twilled gauze, in which the radiating sur- 
face is considerably greater, and the circulation of air less, pre- 
serves an equal temperature. Indeed the heat communicated 
to the wire by combustion of the fire-damp in wire-gauze lamps, 
is completely in the power of the manufacturer; for by diminish- 
ing the apertures and increasing the mass of metal, or the ra+ 
diating surface, it may be diminished to any extent. 
1 have lately had Jamps made of thick twilled gauze of wires 
of 1-40th, sixteen to the warp, and thirty to the weft, which 
being riveted to the screw, cannot be displaced ; from its flexi- 
bility it cannot be broken, and from its strength cannot be 
crushed, except by a very strong blow, ° 
Even 
