2G4 
THE GARDENING WORLD. 
December 25, 1886. 
receives ; and that by early morning it will have fallen 
excessively low—possibly below the freezing point, and 
some of the plants are damaged. At the first visit the 
low temperature is noticed, the fire is re-lighted or 
increased, and the heat of the house raised as rapidly 
as possible. Then the damage is done, for frozen 
plants thawed rapidly, either by exposure to sun or 
fire-lieat, rarely recover. In the event of any mishap 
occurring, the heat must be applied very gradually ; 
and if the weather be bright, the plants must be 
shaded, damping slightly with water through a fine 
rose-can.— Scolytus. 
-- 
HEATING GLASSHOUSES. 
In my last communication I mentioned that, in my 
opinion, a vertical rise of the flow-pipe direct from, or 
at a point as near as possible to, the boiler would be 
preferable to the old method of fixing, which neces¬ 
sitates a continuous rise to the further end of the pipe. 
Since then we have been favoured in your columns 
with two separate plans, both being modifications of 
that which I proposed. The plan proposed at p. 213— 
which is, without doubt, an ingenious one, and, at first 
sight, looks to be a step in the right direction—would 
not, I am afraid, meet with much encouragement. 
This, to me, does not lie so much in the two objections 
which are stated in connection with it, although, no 
doubt, serious enough in these days of reduced incomes 
and corresponding reductions of expenditure in gar¬ 
dening establishments. A much more serious objection, 
in my opinion, would be the extra care and attention 
that a house constructed on this method would entail, 
on account of the extra danger to either plants or fruits 
grown in it. The idea is a good one, so far as it takes 
into account the cold weather ; but what would be the 
likely consequences in an ordinarily, not to mention 
an exceptionally, hot summer ? TVe all know the 
attention requisite to prevent burning and scalding in 
a hot season with even our present lightly-constructed 
houses ; but what would it cost us -with a house 
enclosed, as it were, in a case of hot air, which it would 
be if double glazed ? 
The second plan—that proposed by “A. D.,” at 
p. 230—would, I think, be more preferable, and, 
indeed, it almost meets the views which I have hitherto 
held ; and I can see no difficulty in heating any number 
of houses on this principle, provided it be carried out 
in its entirety—viz., carrying the flow-pipe to the 
highest point at once from the boiler. Of course, with 
boilers and flow's fixed as at present, no great extent of 
glass could be heated satisfactorily by this system from 
a single boiler without an increased expenditure of fuel. 
By this I mean houses in different ranges ; but I think 
that any number of houses or divisions could be properly 
heated in a range of any length, or even two ranges 
side by side, or, at least, with their ends near each 
other. The Messrs. Cannell, and others who have 
tried the plan of heating the upper parts of the houses, 
have had perfect satisfaction with it, I believe, although 
it may differ slightly in construction from the system 
I proposed. 
In any case, even with the system at present gene¬ 
rally in use, I cannot see the utility of sinking the 
boiler more than about its own depth, as the flow 
generally issuing from the top of the boiler is fixed at 
about 1 ft., more or less, from the floor of the house to 
be heated. This is done, I suppose, on the theory 
that heat ascends, and therefore must reach and v-arm 
the upper part of the house. But what do we find in 
practice and also in fact—and I assert it to be a fact 
beyond dispute, although hot-water engineers ignore 
it—simply that the heat from the pipes, in place of rising 
towards the top of the house, is radiating equally in all 
directions ; and so, in addition to raising the tempera¬ 
ture of the house, the soil, brickwork and materials 
near the pipes, including, in many cases, roots also, 
are being actually roasted by their proximity to the 
heat. It is not the heat itself, but the air which it 
warms and sets in motion that rises in the house, 
and the greater proportion of the heat is absorbed 
where not required, and so, therefore, simply wasted. 
A great deal may be said for the better convenience 
and appearance of the pipes, as fixed on the present pre¬ 
vailing method, but these are considerations which 
should not prevent us from finding some means of 
arriving at the same or better results at a far less cost. 
The reduction of the coal bill by one-third or half 
would be an item which would cover some faults in 
appearance or otherwise, if, indeed, that were the only 
favourable result. As to the placing of the boiler in a 
deep stokehole, unless in some exceptional case, there 
is no actual necessity for doing so. — R. Stevens , Poston. 
“Is our present method of house-heating the right 
one 1 ” This question is asked by your correspondent, 
“A. D.” at p. 230. He then proceeds to propound a 
theory, which would have to be based on assumption, 
that heat will descend. I strongly suspect he will find 
“ practice make game of it.” Something analogous to 
this was tried more than a century ago, when four 
flues were mounted on the top of one another along the 
back wall of lean-to houses, expecting them to heat 
right out to the front ; this was a failure, and I fancy 
“A. D’s” theory will share the same fate, unless as a 
preventive of condensation. I am much interested 
in this subject, and would be glad to hear of any 
improvement on the present system, both as regards 
economy and efficiency. 
I have experimented a little on the subject, with a 
view to finding the right position for the pipes in the 
house, and my opinions are quite the reverse of 
“A. D’s.” I find that hot-w'ater pipes, like fireplaces 
in rooms, are placed, as a rule, too high for the effec¬ 
tive heating of their respective spaces. The question is, 
in what part of a glasshouse is the heat required ? First, 
take a plant house, it will at once be admitted that the 
greatest heat should be on the stages among the plants ; 
to economically have this, it is clear that just under 
the stage is the proper place for the pipes. I have 
found that a thermometer placed 3 ft. above hot- 
water pipes will register 5° more than one placed 3 ft. 
below them, and experience teaches me that heat will 
not descend until forced to do so, neither will it spread 
level over the house ; it rather rises at a considerable 
angle to the roof, and, in order that the greatest advan¬ 
tage may be got from it, the pipes should be as near 
the ground level as possible. In the case of a vinery, 
or other fruit house, “ A.D.’s” system might work after 
the vines were up ; but I suspect temporary pipes 
would have to be put in on the old system for the 
first two or three years of their existence, or little good 
would be got from the Vines. 
“A. D” speaks of “the heat under the present 
system being fast cooled in the air, the brickwork, the 
ground beneath, and all sorts of material, alive and 
dead.” I had always thought that it was to heat the 
cold air in a house that the apparatus was fitted up ; 
and as to the brickwork and other material inside, it 
will not take more heat to warm than the same amount 
of air would, and it will keep warm longer, so that in 
it' there is so much stored-up capital which can be 
drawn on at will. Outside walls ought to be hollow to 
prevent waste. 
“A. D.” says, “No wonder boilers are driven to 
their utmost capacity, pipes made almost red-hot, and 
fuel consumed beyond the real needs of the case. This 
leads me to ask direct whether “A. D.” can, with his 
system, efficiently heat a house for, say, stove plants 
at as small a cost in fuel as he can one of the same size 
on the old system ? When boilers have to be driven at 
all, they are either too small for the work, or the 
amount of piping in the houses is insufficient for the 
temperature required. As to the depth of a stoke-hole, 
a little sinking might, in many cases, be necessary. If 
manufacturers of boilers w r ould make the common 
saddle and its allies lower and wider, and send the 
outlet horizontally away from the end, instead of out 
at the top, as is usual, a still greater choice would 
be afforded to owners of glasshouses in fixing the 
depth of their stoke-holes.— R. Bell, Morton Hall, 
Midlothian . 
Begonia Boliyiensis. 
