98 
Rtmarlis on JFood and Metal IJut-JJovse Roofs. 
prices, and some very pretty drawings of hot-houscs recently built with 
patent sashes. I had to make 66 ne\v sasiies at that time, but T told 
the patentee that I could not think of givingf 1 IBs. 6d. at Birmingham, 
for that which I could have made for £1 3s. 6d. at home; even if the 
percentage fee was doubled; and as to their everlasting durability, 1 
conceived it was quite impossible that wood mortices and metal tenoris 
could last twenty years—which was the case, those sashes which I went 
to see had to be changed in less time than those named by Mr. Mur- 
trie, who may well advise gentlemen to pause and reflect before they 
erect such things in a Fruit-forcing garden. 
As to the more recent invention of hot-houses with rafters and saslies 
all of metal, whether copper, cast-iron, or cast-steel, the well known 
powers of all kinds of metal as conductors of heat and cold, and their 
susceptibility of both, as regards their expand ms; and contracting pow¬ 
ers, are so great, that if they do not cram the walls down by expansion, 
nor receive fractures by contraction, they certainly are improper mate¬ 
rials for exciting vegetation, particularly early in the season. 
The following practical case will bear upon the point in question;— 
I have seen a cast-iron pine-stove, with the metal so much contracted in 
the winter mjonths, that the interstices were obhged to be stuffed with 
moss and wool, and even then the hoar-frost has appeared in. some pla¬ 
ces in the inside of the roof, and the gardener assured me, that in hot 
weather the expansion was so great, tliat it was very difheiilt to move 
the sashes for ventilation, and the conducting powers of the metal ren¬ 
dered a continual watching necessary, to regulate the temperature. 
It is now frequent for retired tradesmen to have g'ardens, and to build 
small Hot-houses. I know an instance of one who wished to have a few 
grapes and keep a few plants for amusement; he took bad advice and 
built one of those gay, expensive, kickshaw things, with an idea to 
eclipse a more frugal neighbour, who had a wood hot-house, but he 
soon found out that it was a mistake; the money was gone, and the pro¬ 
duce never came, under the management of the gentlemiaii and his man- 
of-all-works. 1 could give names, &c., but that would be adding insult 
to disappointment,—a caution toother gentlemen is here intended, lu 
cases of this kind, the hot-house of some intelligent nurseryman often 
presents a tolerably good pattern ; there is generally economy and use¬ 
fulness combined. Sometimes cases occur where sucli erections can be 
attached to the library or drawing-room—a good plan and paper on this 
is given in the “ (Jardencr's Magazine vol VI. page 664. 
When it is intended to build a hot-liouse, there gcncrallv i^^ some 
particular specified purpose in view, such as grapes, peaches, jiinc- 
apples, or botanical plants, more or less hardy, &c.; tliose consider¬ 
ations ouglit to rule not only the form and dimensions of the house, but 
the piicli of the roof, which is a most '"sscnlial point as regards early or 
