130 
COST OF FITTING UP AND GENERAL MANAGEMENT 
OF GREEN-HOUSES. 
All green-house plants being natives of temperate climates, as the Cape of 
Good Hope, New Holland, &c., require very little artificial heat, and that only 
under certain circumstances. 
In building a green-house always place it so as to receive the full benefit of the 
morning and mid-day sun. This is particularly necessary for the welfare of the 
plants during winter and early in the spring. 
Light is indispensible, therefore, so construct the building, that as little light is 
obstructed as possible. Also the back and front sashes, or ventilators, which in our 
opinion, are far better, should be fixed to open with ease, for the admission of as 
large a quantity of air as will be required at different times in the year. 
With regard to the materials of which the roof ought to be constructed, we 
would always give preference to wood, except in certain forms of structure, when 
metal may be used with advantage, of which we shall speak more at length at a 
future time. 
The mode of glazing may in some measure depend on the taste of the pro- 
prietor, or those into whose hands he commits the care of the building. In no case, 
however, should the laps of the glass be puttied, because the circulation of the air 
is thereby greatly impeded. If beauty is an object, the glass on the roof should be 
cut in squares of about six inches by seven inches, but for cheapness and strength 
six by three inches is preferable ; and if the laps be small, and the workmanship 
be done judiciously, the glazing will look very well. 
Mr. Saul’s system of glazing is intended to protect the rafters and bars entirely 
from exposure to the weather, and to give the outside of the roof a smooth and 
even appearance. B, is a section of the rafters ; d, e, is a thin piece of metal, 
which runs betwixt every joint on the sash-bars, with the upper part divided, so 
