132 THE COTTAGE GARDENER AND COUNTRY GENTLEMAN’S COMPANION, June 2, 1857. 
as well as on the health of the inhabitants within 
its reach. Now, with such examples before our eyes, 
whore even the sweetening influence of the open air 
could not ward off the evil, it would seem impossible for 
the inmates of a closely-confined apartment to escape 
injury even where those pernicious gases are in a much- 
diluted state, and, as all combustion requires an abundant 
supply of fresh air, it follows that such combustion 
cannot go on, and have the air in the sweet, pure state 
it was before consuming it; or, in other words, a so- 
called smoke consuming apparatus must give off a 
description of heat much charged with gases produced 
by the change combustion has made in it. That these 
gases are injurious every one knows that has been in 
contact with charcoal burning in a close room, and 
all modes of heating a room or hothouse without a 
chimney or outlet for the fumes and vitiated air must 
be bad, even with the aid of these auxiliaries. Many 
close iron stoves are offensive, ordinary gas burners are 
unpleasant and unhealthy without a free outlet, and 
most Arnott stoves give an offensive smell to the atmo¬ 
sphere of a room when a good draught does not set in 
from the door to the chimnev. All these and other 
instances may be adduced as proving that the system of 
using any other mode of heating but that which gives 
a free circulation of air is bad, and ought to be avoided. 
Various modes of heating hothouses have been adopted 
during the last few years with varied success, and it is 
probable that some better mode still may ere long be 
discovered that will give greater circulation to the air 
than any that is now in existence. At the present time 
by far the greatest number of structures are heated by 
hot water or smoke flues of some sort or other, and ven¬ 
tilation is mostly effected by outlets at the top and 
bottom of such buildings; but, as the major part of such 
structures are closed at the time when fire heat is most 
applied, it follows that the heat given off has a sluggish 
character, more especially from hot-water pipes or tanks. 
Now, this is the great defect in hot-water heating in my 
thinking, and it it could be remedied so much the 
better. A limited ingress of external air entering at the 
lowest point and passing over the hot-water pipes is the 
best mode at present known to create a circulation, but 
this is certainly open to much improvement. The 
heating properties of hot water are certainly as good as 
need be, but something must be contrived to give a 
greater circulation to the air, and consequently to the 
heat. Letting in large quantities of cold air at bottom, 
and letting out the heated portions at top, will, of course, 
maintain a proper circulation, but it is at a great waste 
ot heat. It would therefore be better if we could give 
motion to the air in a hothouse without exchanging it, 
by making it revolve around the building, and finally 
pass oyer the heating place again. If this could be 
carried into effect we should have little to complain of 
about hot water, and we do not despair of its being so. 
Polmaise heating is but an improvement on the old 
flues in this respect, only that it gives a greater circula¬ 
tion to the air inside the house by the continuous stream 
which is made to pass over the heating apparatus; in 
fact, a well-constructed Polmaise apparatus that works 
well and safely is unquestionably the best mode of 
heating I know of. Observe, I make the qualification 
“ when it works well,” which it does not do in every 
place, and has been abandoned in many instances; but I 
lately visited a place where it was in excellent working 
order, and nothing could exceed the health and good 
appearance of everything inside the hot pit to which this 
mode of heating was applied. Cucumber plants in the 
• 11S ^i WOe ^ m Jauuai T l°°k e d as well as they generally do 
m May and other things equally good. In this case 
the circulation was so perfect that a visible motion was 
given to the leaves of the plants inside, the doors and 
ventilators being all closed, the air of the house being 
kept in continuous motion by being obliged to pass over 
a heated apparatus, and, travelling along a sort of flue 
underneath a bed in the centre of the house, was let out 
at various places along the side of the bed; but a large 
portion reached the extreme end, about forty feet from 
the fire, and near to which were the openings in the 
floor of the pathway communicating with the return air- 
drains to the heating apparatus, the heating apparatus 
being mostly, or rather wholly fed by air drawn from 
this source, and, as the expansive powers of heat urge 
on the continuous stream of air coming in contact with 
it, a circulation is kept up which is even perceptible to 
the feel of the visitor. That this circulation is healthier 
than the dull, stagnant heat arising from hot-water pipes 
and other sources I think every one will admit, hut the 
great drawback is the liability such things have to go 
wrong, even when they are placed under the care of 
those wishful of making it answer. Added to this, I 
believe the apparatus is rather extravagant in the quan¬ 
tity of firing required. Waiving these great drawbacks, 
which, by the by, may in time be remedied, and then 
we have a great improvement in heating; for not only is 
this system adapted to hothouses, but it is also appli¬ 
cable to dwelling rooms of all kinds, the heating of a 
large mansion near here having been successfully accom¬ 
plished on this plan after all other modes had failed to 
do so satisfactorily. 
Now, this is a fact worth noticing, and I have no 
doubt but some modification of the plan will in time 
be adapted to garden structures free from the defects of 
those already in existence. A circulation of pure air 
has been at all times an object of the greatest 
importance to all public buildings of general resort, 
and various have been the means adopted to heat them. 
The loftiness of churches generally renders them more 
difficult to heat than to ventilate, especially in those 
where no contrivance for heating was thought of at the 
building of the edifice, and the whole work left to be 
done by some Arnott or other stove stuck in the centre 
of the principal aisle or passage. This state of things 
has not improved in every new case brought before the 
public in the last few 3 r ears, although we have had no 
lack of inventions bearing that way. Some eight or 
ten years ago, or more, the mode of ventilating recom¬ 
mended by Dr. Read was strongly advocated, and 
several public buildings were furnished with his ap¬ 
pliances for effecting that object, which, from what I 
could learn of the matter, were diametrically opposed 
to all other modes heretofore adopted. I believe Dr. 
Read’s system to have been to convey the heated air to 
the highest part of the building, where a perfectly air¬ 
tight chamber received it, and it was thence made to 
descend to the base of the building, to be again heated 
to warm the building or room in which it circulates, 
and continuing the same process again, renewed only 
by such accessions of out ward air as would find their way 
inside by means of the doors and other openings, the 
windows being closely glazed and fastened down. What¬ 
ever benefits there might be in this plan in winter there 
were certainly great disadvantages attending it in warm 
weather, as 1 well remember one of our judges of 
assize suffering, as well as a crowded court, from the 
heat, directing the windows of the court house to be 
opened, but was told it could not be done, as by Dr. 
Reads instructions they were all closely nailed down. 
His lordship, however, soon got over that difficulty by 
directing the glass to be broken. The wands of the 
mace bearers and other things speedily created an 
opening, through which the heated and vitiated air was 
expelled, much to the satisfaction of the whole court, 
who, it is needless to say, applauded the summary 
act oi the worthy judge. Though plants, like human 
beings, require a continous supply of fresh air, yet there 
is not so much necessity to have large admissions of 
