On Metallic Hot-houses. 295 
From this time, I never conscientiously recommended this descrip- 
tion of bars, but many improvements have since been made, some of 
vhich have superseded the original patent. I still however fear they will 
never answer like wood, when heat is required throughout the winter, as 
in the case of Pines; nor do I ever recollect an instance where this sub- 
ject was brought forward in my presence, that 1 did not plainly express 
those very doubts on the subject; for I never viewed a metallic roof 
without considering it very unequal to wood in point of durability. 
I had two houses built on Jordan's principle under my care, when in 
the service of the late Lord Waterpark, of Doveridge. I never found 
them, however, eqiial to an old house which was built of wood 30 years 
before the metal ones. Both of these houses appeared to answer the 
purposes intended very well, but I was always compelled to be more 
particular in attending to give air to them, than to the one with a 
wooden roof; and 1 believe this to be one great reason why they are 
brought into such disrepute, for the close manner in which the glass is 
filled up prevents the least circulation of air: a practice, which I think 
has done more towards their failure than any thing else, \\ hilst in the 
old-fashioned wood houses there is a constant supply of fresh air passing 
through the caps of most of the squares. This appears to be generally 
unnoticed both by proprietors and gardeners. It has been seen that 
matters went on better under a wooden roof than a metal one, which is 
evidently because the former had the means of ventilating in the best of 
all methods; while the latter was so sealed up, that it was impossible for 
the dampness thr;t arose during the night ever to escape, so that when the 
heat of the sun, in the morning, caused a dense vapour, — actually per- 
nicious through its constant confinement, — all the leaves in the house 
became debilitated, and if air were not speedily given, would in the end 
certainly prove fatal. So much for the reason of leaves showing a sickly 
culour under a metallic roof. I shall now speak of what I conceive to 
be ihe benefits arising from metallic roofs; but before I do this, I shall 
just observe that the expense of these roofs, (from the information I have 
been able to obtain, and from what has come under my own observation,) 
where they were built without any particular ornaments, was always es- 
timated at double the cost of one constructed of wood. 
These roofs, I conceive, are admirably calculated for the large Orna- 
mental Conservatories, and I think the person who first adopted them 
deserves the warmest thanks of every person who is an admirer of gar- 
dening. I am sure it will ever give me pleasure to hear that those who 
have embarked in this business meet with the encouragement they so 
richly deserve. 
From the commencement of Mr. Jordan in this line of business, I 
have been on the most intimate terms of friendship with him, and when 
in the height of prosperity, he made my cottage his home whenever 
