33 
GARDENING AS A SCIENCE. 
No. II.— TEMPERATURE. 
So much has been written upon the temperature, by day and night, of stoves, 
vineries, and other structures devoted to the purposes of general 44 forcing," that it 
might appear superfluous to devote another line to the subject ; nevertheless, as 
heretofore it has involved a series of contradictions, we hope that a review of some 
important facts, with a few relative observations, may be interesting. 
The radiation of heat from the surfaces of flues and hot- water pipes, is a problem 
to which many arithmeticians have devoted their attention. A clever paper by 
Mr. Tredgold, on " The relations of heat, moisture, and evaporation," might be 
cited ; and it appeared in the first volume of Loudon s Gardener s Magazine, p. 37- 
But the inquiry is so hampered with contingencies, that few amateurs could render 
it available : to them it will in most respects be sufficient to observe minutely the 
maximum of heating power which the apparatus at command can produce, and 
the degree of limitation within which, with the least possible trouble, it can be 
controlled. If any species of machinery, aided by accurate glazing and adaptation 
of the sashes, can be made to raise a temperature of 65° at eleven o'clock of a frosty 
night, and, by the mere banking-up of the fire, to retain that heat within 5 degrees 
(60°) till eight of the following morning, there will be ample cause for satisfac- 
tion. Economy of fuel must, however, be consulted ; for so much depends upon 
the action of the furnace, that one shall rapidly consume double the quantity 
required by another, without any adequate result. 
Whenever hot water is preferred, and can be introduced, we earnestly recommend 
the gardener to avail himself of the flue. A chimney of some sort must be erected ; 
and many content themselves with a simple, upright shaft, conducted through the 
roof of an exterior shed ; but why this waste of radiating power, when a few extra 
shillings would carry a flue from one end of a house to the other, and thus husband 
the heat of the ignited fuel ? Any brick flue can be rendered impervious to smoke 
if the mason be master of his art, and coat the inner surfaces of the bricks with 
well-wrought parget. Security is of the greatest consequence, and that can be 
obtained by a good flue without prejudice to vegetation. We write advisedly, 
for in a handsome conservatory not remote from us, the water of all the pipes was 
frozen throughout by the sudden accession of very severe frost ; and before the ice 
could be dissolved, or the water put in motion, many hundred plants were utterly 
destroyed : the flue from the furnace, had it passed through the house, would have 
radiated heat sufficient to defend those half-hardy tenants of the conservatory, 
which, however, could not survive the decomposing agency of 7 degrees of actual 
frost during a period of twenty-two hours. 
We quit the general consideration of flues, water-pipes, and furnaces, by 
observing that a short time since, a very clever person made mention of a new 
VOL. X. — NO. CX. F 
