Remarks on Wood and Metal Hot-House Roofs. 149 
Article III. — Comparative Remarks on Wood and Metal 
Hot-House Roofs. By Mr. J. CuR, A¥orcester. 
Gkxtlemex, 
From the very favourable reception Mr. Mc.Murti-ie's letter 
on Metallic Hot-houses, seems to hare met with, I know not whether 
the following remarks on the subject, will be admissible in your publi- 
cation ; but being conscious of the importance ©f the eubject, and of 
the necessity there is for something to be said on behalf of metallic 
hot-houses, when professional men undertake to ridicule those struc- 
tures, 1 beg leave to oft'er my opinions on this interesting topic. 
P'or many years in my youth, I was accustomed to no other kind 
of hot-houses than those built of wood; but on becoming gardener to a 
gentleman who was about erecting six houses and t\^'0 pits, I advised 
him to use metal, as I considered it to be best, but havnig a great deal 
of wood by him, he preferred building with that material. The builder 
he employed erected three houses and one pit, with the wood, when 
he and my employer disagreed, and a builder from Birmingha'ra, was 
sent for, who erected the other three houses and pit, of metal; and 
as I have had the care of all of them for the last twelve years, I hope 
I shall be excused, if, from the experience I have had, I venture to 
give my opinion on their relative merits. 
I could never see much difference in the crops of these two kinds of 
houses, except that the grapes in the wood ones seldom set so well as 
those in the metal ones, which I considered to be occasioned by the 
rafters and sash-bars beino- obligfed to be made so much thicker in wood 
than in metal, thereby shading the bloom, and causing an impediment 
to its setting, for the more light the bloom has, the better it will set. 
The metal houses, in this particular, have a decided superiority over 
wood ones. 
The chief objection urged against metal, is the attraction of heat, — 
this is mere nonsense ; for if the metal is kept well painted, it attracts 
no more heat than wood; this T proved, by taking a piece of metal 
and a piece of wood, both well painted, and placing them against a 
south wall, two feet asunder; I examined them every half-hour, and 
could not perceive that the metal heated one degree faster than the 
wood. I also put them both into equal quantities of water, and one 
heated it just as much as the other. So much for the attraction of 
heat, which Mr. Mc.Murtrie says, injured his pines, when they came 
in contact Avith the rafters. IVly pines in the wood pit, are often much 
injured by the shade of the rafters, they making it so much darker 
than the metal one. 
