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TEMPERATURE AND METEOROLOGY. 
We lately described a house which, by the heating power of a chamber acting i 
upon air circulating within it and throughout the area of the building, became very 
effectively warmed. Subsequently, an opportunity has occurred to examine another 
erection constructed upon still better principles. This shall not be lost sight of, but 
in the meantime, while waiting for positive and conclusive evidence of facts, it will 
not be unprofitable to appeal to sound theoretic principles. 
1. It is a maxim, or law of physiological chemistry, as applied to aerial fluids, 
that each gas becomes a vacuum to every other gas : thus, if a vessel contain hydrogen, 
the lightest of all bodies that are known to possess weight, and a quantity of common 
air, nitrogen, or oxygen be let into that vessel, the gas or gases so introduced will 
pass interstitially through the particles of the hydrogen, without chemically uniting 
therewith, or requiring any additional space. We are indebted to the late Dr. 
Dalton for this most interesting discovery. 
2. Radiation is that species of action by which heated bodies communicate heat 
to other bodies, or rather to air interposed between them; the power diminishes 
in geometric progression, according to distance. If a surface radiate heat, the 
intensity of that heat will be equal at equal distances, but it decreases, in inverse 
proportion, at unequal distances. How very irregular, therefore, must be the action 
of all our present radiating surfaces. A flue, for instance, shall be almost red- 
hot at its entrance — six feet from that point its surface may not sustain 150° — 
and at the opposite end of the house, the hand shall scarcely detect any sensible 
warmth. Now, as heat diminishes in inverse progression — if, at two feet, the 
radiated particles raise the mercury of a sensible thermometer 40°, the same 
instrument, remaining exactly opposite the same part of the flue, but at four feet 
instead of two feet distance from it, will indicate an increase of 20° only — i. e., as 
2 : 40 : : 4 : 20. But when the whole surface loses heat at every foot of its course, 
how infinitely complicated must be the sum of its radiating power. We stand in 
need of improvement ; and fortunate it is that the prospect brightens, and promises 
not to be delusive.— More of this at an early opportunity. 
Equability of heat is rendered more desirable by the accidents, which formerly 
were of frequent occurrence, with the old fire-flues; these, of course, have 
ceased where hot water has been substituted ; but some years since, a parcel of 
damp moss was laid on a flue near its entrance, nothing was apprehended, Bait in 
the morning, a strong, foetid, ammoniacal odour was detected, and on opening the 
house the moss was seen reduced to ash ; while vine and other leaves, at the remote 
end of the house, were completely decomposed and shrivelled, though no heat had 
approached. An apparatus, to produce healthful warmth, must affect the air and the 
air only, and operate by means of its interstitial diffusibility. 
