222 
THE COTTAGE GARDENER AND COUNTRY GENTLEMAN, Jaitfaey 15, 1861. 
for heating by a good common flue, as however carefully the 
other apparatus may be fixed, a good portion of the heat will 
pass up the chimney, however carefully the damper and the 
draught at the ash-pit door may be regulated. Where economy 
in fuel, therefore, is a great consideration, and a hot-water boiler 
is used for a small house, a flue from the furnace should pass at 
least a certain length through the house. Where a large boiler 
has to heat several houses the loss of heat thus sustained by 
passing up the chimney would be no great matter when divided 
between the different houses. 
HEATING BY STEAM. 
This mode of heating is only fitted for large establishments 
where a person can always be in attendance, as little or no avail¬ 
able steam is secured, unless the water in the boiler is kept at 
boiling-point. I lately knew of a couple of houses near each 
other thus heated, but hot water was substituted, and found to 
be a great economy in fuel, labour, and attendance. The great 
advantage of heating by hot water is, that whenever the water 
becomes hotter than the place to be heated, heat will at once be 
given off, it matters not whether the water be 100° or 200°. 
Perkins’ system of heating by hot water had some of the ad¬ 
vantages and few of the disadvantages of steam. A coil of strong 
pipes one inch in diameter was fastened in the fireplace, the 
upper pipe from the coil forming the flow-pipe, and that con¬ 
nected with the bottom the return-pipe. The whole heating 
was accomplished with an endless-pipe, as in the whole there 
was no opening. At the farther end from the boiler or furnace 
there was an expensive pipe double or treble the size of the one- 
inch pipe used for heating, and at the bottom of that expensive 
pipe there was an opening for seeing how the pipes were sup¬ 
plied with water, and adding a little when necessary; but except 
at that time, that opening was rendered air and watertight. 
Whatever heat was applied was thus given off by the pipes, 
and when much heat was given owing to the pressure, the water 
might reach to double the heat of boiling water. 'There could 
hardly, however, be said to be economy in the small pipes thus 
highly heated, as they required to be very strong and carefully 
made, and besides the air brought into contact with pipes at 
from 250° to 300° and 400°, was too much dried, and rendered 
unhealthy by the scorching of organised matter that the air 
might contain. Most gardeners would rather increase the 
number of their pipes than have the water in them higher than 
from 180° to 200°. 
The Syphon system by Eewly was also a very ingenious and 
scientific mode of heating, but as we once found to our cost, the 
smallest aperture in the pipes, even though the size of the point 
of a pin, and which though scarcely to be found, yet admitted 
air to the pipes was fatal to the whole system. Any one who 
tries to empty a cistern or a barrel with a syphon not quite air¬ 
tight will find the reason. 
All experience and observation, therefore, coincide in the 
statement, that the simpler the mode of heating the more satis¬ 
factory will it generally be. Ail intricacy in boiler and pipes 
only adds to the labour and expense, nothing is simpler than 
the whole theory and circulation of heated water. Apply heat 
to water above 40° and it becomes lighter and expands. Place a 
kettle on the fire brimful of water, and long before the water 
actually boils it will run over the sides of the kettle, because it 
cannot find room inside. If before that water got so hot we had 
plunged our hand into it, we should have found that the farther 
we went down the colder it was, and the nearer the surface the 
hotter it was, - especially if the vessel were covered by a lid. 
Every washerwoman knows all about this who uses a wash¬ 
house copper. Instead of waiting for a whole boiler to be heated 
sufficiently she will take as much as she wants pretty hot, by 
dipping two cr three inches deep from the surface, which will be 
hot, whilst that deeper down is comparatively cool. These 
simple facts explain the whole theory of circulation. Give vent 
for the heated water to flow, and bring back the cool to supply 
its place. The flow-pipe must, therefore, be at the top of the 
boiier, or nearly so, and the return-pipe as near the bottom as 
possible. The first hot-water heating I saw was done with a 
washhouse boiler supplied with a wooden lid, a hole near the 
top for the flow-pipe, and one near the bottom for the return, 
both pipes going to a cistern on the same level as the boiler. In 
all such boilers, exposed to air, the circulation is more languid 
than when the boiler is closer and sunk a little below the level 
of the pipes. 
At page 120, fig. 5 is shown how a bodcr may be fixed over a 
flue so as to supply heated vapour. If such a boiler had a second 
pipe near the bottom, and the top and bottom ones were joined 
at the farther end either by a semicircular band (, with an air 
pipe in it, or both terminated in small open cisterns, there 
would be a circulation of heated water as long as beat was 
applied. 
As I write chiefly for amateurs I may mention that such 
modes have been used for hot vapour, and also for additional 
heat by hot water to propagating-pits inside of a house heated 
by a flue. One of the most simple things in this way I have 
seen tried was a bend, and a nine-feet length of a four-inch pipe, 
Fig. 12. 
the bend being placed over, or, rather, in the fireplace, tilts end 
of the bend just coming outside of the brickwork, and there 
secured with a wooden plug and red lead, and the other end of 
the pipe terminating in a small cistern. A couple of inches of 
rough gravel were put over the pipe, A bed was formed 2 feet 
wide, and bottom heat was thu9 obtained for propagating. 
By such an arrangement the hottest water went along the upper 
part of the pipe, and the colder by the lower part; but the 
circulation was not so complete as in another similar case where 
two three-inch pipes were used—one entering near the top of 
the small cistern, and the other returning from near the bottom. 
So well has this answered merely by putting the semicircular 
Fig. 13. 
joint in the fire that heats a flue that the enthusiast who manages 
it, sometimes desiring a little heat in his bed when he wants little 
in the flue, has had a damper made, that, when the smoke is 
mostly gone, he can put in nearly home at the mouth of his 
flue, and keep the most of the heat about the bend of pipes 
which he calls a rare cheap boiler; and he also contemplates 
moving his little cistern 9 feet further on, so that by put¬ 
ting on another two nine-feet of piping be can make his bed 
IS feet, instead of 9 feet, long. A coil over, or partly in, the 
fireplace would answer better still; but that would have to be 
made, and, therefore, entail expense. As mere auxiliaries under 
such circumstances such simple modes will be useful. 
Where much, however, is to be done with hot water a boiler 
must be set apart to do it, and of a size in proportion to the 
work to be done. I have already stated that an open boiler, 
like a washhouse copper, will do for a single house; but that 
the power will be so far diminished. In heating different houses 
on different levels from one boiler, or even a single large house, 
the boiler should, if possible, be sunk two, three, or more feet 
below the general level of the pipes. It is just as natural for 
heated water to rise as for cold water to fall; and in either case 
an incline will be an assistant in the matter. The rise even of 
an inch in 40 feet is better than a dead level. 
In speaking, as above, of the size of the boiler, the word size 
must be used in a particular sense when applied to boilers for 
hothouses. A boiler may be very large, and yet very unsuitable, 
and possessed of little power. The smaller the fireplace, pro¬ 
vided it be sufficient, the greater the economy of fuel, because of 
the more perfect the combustion—the larger the surface of the 
boiler presented directly to the action of such fire, and the 
smaller the quantity of water in the boiler to be heated safely in 
proportion to such surface exposed to heat, the greater and 
quicker will be the action of the boiler. 
For instance: For heating merely a good bulk of water whh 
little fuel in a small fireplace, hardly any mode will beat the. 
washhouse copper, nicely set, with the fire playing directly on 
the lower part of it, and the heated air and flame playing round 
the most of it. For a strong continuous heat in a hothouse 
there might, be worse plans now ; but in cases where brisk and 
sudden action are required, few plans could be worse. You 
must heat considerably that great mass of water before you could 
have hot water in your pipes. But now, just take another 
