WOOD AND METAL CONDUCTORS OF HEAT. 583 
Any person may prove Mr. Cur's experiments and assertions to be 
founded on error, very satisfactorily by tbe follow^ing method: — 
Take equal sized rods of iron and wood, both being painted ; cover 
the half of each with wax or tallow, plunging" the other half in hot 
water or sand, and observing which soonest indicates the presence 
of heat — most assuredly the metal. To show the striking disparity 
between metal and wood, as conductors of heat, let rods of iron, 
copper, tin, lead, glass, bone, and wood be treated in the manner 
stated, it will be observed that the wax melts on each particular rod, 
in the order of its jiower of conducting heat — the metals first, and 
these two in their particular order, then the glass, and last of all the 
wood. Now, supposing the outside of a metal rafter to be heated to 
180 deg. it is evident that the inside will be almost as hot, whereas 
if a wooden rafter was heated on the outside to tlae same degree, the 
inside, of the wood being a bad conductor, would only be at the 
same temperature of the house ; a very little reflection upon this will 
very easily and truly account for the scorching of Mr. M'Murtrie's 
pines. 
Upon this principle is founded the general complaint against 
metal houses, called (though unphilosophically) the attraction of 
lieat and cold, for if the external atmosphere is hotter than the in- 
ternal air of the house, or the rafters heated by the sun's rays, it is 
evident that a quantity of caloric will be given ofi' to the air in the 
house, and in this case make it too hot ; on the contrary, if the ex- 
ternal air is colder, there will be a continued absorption of heat from 
the inside to the out, till an equilibrium is restored, this of course 
will make the house too cold. 
This then, is what Mr. Cur calls "mere nonsense," and which 
he, in his own opinion, has proved to be such, but I would with all 
humility inform Mr. Cur, that before he again summons the as- 
surance to call any opinions "mere nonsense," he will first prove 
liis own to be sound sense ; and before he attempts any more to 
write upon heat, or heat in connection with metallic houses, I would 
advise him earnestly to study the properties of, and the laws which 
regulate the science of caloric. 
In writing this, T am neither actuated by motives of interest on 
the one hand, or feelings of prejudice on the other; but solely from 
a desire of seeing liberality of sentiment triumphing over bigotry, 
knowledge over ignorance, and truth finally overcoming all miscon- 
ceplions and errors. 
Ephebicus Horticultou, 
S.S. Monk V^, 1832. 
