232 
THE FLORIST’S JOURNAL. 
can be procured with equal facility. The means by which this 
is brought about is the introduction of small tubes, open at 
one end to the external air; entering the frame, passing for some 
length through the hot water, and then having their discharging 
extremity in the frame. It is obvious that by this simple contri¬ 
vance, and without any additional apparatus, dry air at the re¬ 
quisite temperature may at all times be delivered into the frame. 
212° is of course the limit above which the temperature cannot 
be raised by this means, but that is a degree of heat which no 
plant can bear. The temperature is regulated by the length of 
the air-tubes within the hot water, being greater in proportion 
as they are longer, and the lengths and number of the pipes to¬ 
gether may be adjusted to whatever degree of heat may be re¬ 
quired. It might be as well however, if there were valves 
attached to the external extremities of the air-tubes, so that 
they might be wholly opened or wholly shut, or partially used 
to any extent that might be desired. This method of giving air 
to plants is far superior to that of opening the lights of the 
frame, for when these are opened the cold air, as has been al¬ 
ready stated, is applied directly to the plants, and moisture 
is condensed upon them; but when warm air is let in, and 
further down the pit the better, there is no chilling, and the 
gradual letting in of the warm air by valves would prevent any 
sudden change of temperature; and sufficient moisture may al¬ 
ways be commanded by applying water to the heating pipes; 
but this is scarcely ever required for such plants as are usually 
kept in pits or frames during the winter; the great desideratum 
being to keep the atmosphere about them as dry as possible. 
And it is in this particular that pits heated By means of hot- 
water pipes or flues are so essentially superior to wooden frames 
and fermenting materials. Every pit or frame, whatever its con¬ 
struction, intended for the preservation of plants through the 
winter, should be entirely above the surface of the earth, and 
rather elevated than sunk; an efficient drain should be also 
constructed to carry off all superfluous water which may escape 
from the plants when watered ; and open stages should be 
placed for the pots to stand on. Among other things to be par¬ 
ticularly observed is the removal of anything likely to stagnate 
or render impure the air within the pit or frame ; and it should 
