267 
THE COTTAGE GARDENER AND COUNTRY GENTLEMAN, February 5, 1861. 
system went afterwards by tbe name of Polmaise. All 
we gardeners had gone astray, and confounded Polmaise 
with the workings of the wind out of doors ; others who 
were not gardeners took up that notion, and fortunately 
there are some yet alive who can bear witness to this 
very fact, and who will insist on it to this present hour, 
that Polmaise, or au under and an upper current of air 
in a hothouse to keep it warm, is a better way of heating 
and airing hothouses than the way that has been in use 
by Nature from the foundation of the world, for heating 
and airing the earth, and all that come forth of it. But 
on a small scale fighting against Nature does not seem to 
be worth taking into account. 
Mr. Rivers’s brick ovens in the centre of his Rose-pits 
for forcing them, and for keeping them from cold and 
harm, as explained by himself, and Mr. Lane’s plan on 
the same foundation, as Mr. Fish told us, are both on the 
principle of sucking back the under current to be re¬ 
heated, and to return to the same work on a higher level, 
or Penn’s system, or Polmaise on the mildest scale. And 
there is another corroboration of the fact by Mr. Cullerne, 
in The Cottage Gardener of last week, page 258, whose 
most practical observations on this way of heating I 
would earnestly advise every one who has a stake for 
burning things against, to consult over and over again, 
and then to go and do as he did and advises to do. 
On a small scale, also, have all our hothouses been ven¬ 
tilated on the system of two currents—a top and bottom 
current.. The Crystal Palace is on a large scale, and is 
not so aired—it comes a step nearer to Nature than we 
have been accustomed to practise. The only thing on 
which I had a doubt of all the things I said about the 
Kiddean system of heating, was the working of it upon 
the.level, and I am sustained in that doubt by the ex¬ 
perience of Mr. Cullerne with his Cucumber-house; but 
as his was partly Polmaise, his oven being inside, the ex¬ 
perience arrived at by that means is not absolute, either 
for or against the working of the Kiddean on the level, 
and we want actual practice from outside ovens before we 
can safely rely on the level going in of heated air to keep 
a greenhouse warm. 
Then, as to the invention of this new mode of heating, 
I doubt not but it is the oldest and the best one of all we 
know of since the beginning of the old flue to the com¬ 
mencement of the hot-water system ; and Penn’s and 
Polmaise were wrong deviations from a good beginning— 
which ended, however, on the very day it was first tried, 
owing to a private defect in the setting, and which defect 
could not be discovered without pulling a most compli¬ 
cated and very ponderous machinery to pieces. That 
was, probably, in the early days of George III., for 
whom the origin of the Kiddean system was erected and 
failed at the Stud House, Hampton Court. Every 
possessor of that Stud House, from then till now, had a 
fire and failure with that machinery. “ Old King,” who 
is just gone to his account, was gardener at the Stud 
House from hi3 youth upwards, and as long as he could 
draw one leg after the other, and during his last illness 
; the Marquis of Breadalbane allowed him his house and 
his usual emoluments under Mr. Kidd; but poor King 
could hardly tell of the origin of the great air, or hot-air 
I vault, only that it was put up in the reign of George III., 
and that through all the changes of Governments since 
i then, and with every new Master of the Horse Mr. King 
had to try to get the hot-air furnace in motion, and when 
he failed in such attempts, it was usual to call in some 
lecturer or scientific preacher of air-in-motion as it was 
and should be ; but all such might have preached and 
pi’actised as well on cold air as on hot, for go or come it 
would not, nor never did till Mr. Kidd resolved to fathom 
it to the bottom, or burn his fingers and toes in the 
attempt. Now that it is found out, and proved in 
practice, by one of our very best practical men, that the 
oldest idea of heating by hot air is better for plants and 
for man and beast than any of the suckers which have 
been pulled from the root-stock of the original idea by 
Scotch lairdB and English artists. And there it is and 
has been at work during the hardest weather we have 
experienced lately under the eye and direction of one of 
our best practical gardeners—Mr. Kidd. 
As we are likely to be again engaged on a discussion 
of heating with warmed air, although the child is only 
an adopted one of mine, I cannot let slip a palpable 
error into which “ W. C.,” page 259, has fallen between 
two stools—between the Kiddean and the Polmaise 
systems, where he says the Polmaise has the advantage 
over the Kiddean—viz., “ the constant circulation of the 
air when every ventilator is closed.” That is entirely 
a great error. Cold air drawn from the inside of the 
house through the suction of the furnace, will cool the 
heat in the fireplace just as soon as the cold air from the 
source of Nature,'from the open air admitted through the 
ventilators. As long as there is any heat in the brick¬ 
work the circulation will not cease in the Kiddean 
system ; but it has been proved again and again, that the 
circulation of Polmaise did actually stop while the furnace 
was red hot—a thing which is simply an impossibihty'in 
the Kiddean system. 
The only “ disadvantage ” in the two systems, there¬ 
fore, is more liable to occur in the Polmaise. The escape 
of gas, or bad smell from the fire, is much more liable 
to occur in the Polmaise arrangement of the fireplace 
than in the other; indeed, with a common degree of care 
in building the fireplace and hot-air chamber, no gas or 
smell can get into the circulation of the Kiddean system. 
Like the old woman's salt, the air in the Kiddean system 
is always fresh and fresh, and there is nothing to get out 
of order in it. All the care should be expended before 
lighting the fire for the new and much more superior 
system of Mr. Kidd, and that care should be to have an 
ample fireplace, and a large air-chamber. That is the only 
secret from first to last. You can make a small fire in 
a large fireplace, just as they say in Scotland about 
preaching a sermon in the end of the kirk. Mr. Cullerne 
had his fireplaces large, and “ the fires were frequently 
in for a month together, and never required making up 
after six or seven o’clock in the evening till six o’clock 
in the morning.” Just think of that, and not nearly so 
many coals are burnt in this large fireplace as in the little 
cruets which nine-tenths of the economicals believe to be 
the best for their purpose; but which, indeed, are the 
most wasteful of all contrivances for the economical 
management of the products of combustion. In Here¬ 
fordshire, where Mr. Cullerne practised this economy, 
they all bake their own bread in their large brick-ovens. 
They heat these ovens with all manner of wood-faggots 
in preference to coals, when they can get them; and I 
would always advise the fireplaces for all greenhouses 
to be made so large as to be able to burn wood and 
plenty of it, or any thing that will blaze away quickly— 
that is, the Kiddean fireplaces for such temporary work. 
Then when you saw a sudden turn in the weather before 
going to bed, and your own urgent need of the circulat¬ 
ing medium against the frost, in with a handful of 
shavings or a whisp of straw, out with a lucif and set 
it in a blaze, cut the tie-band of a faggot of brushwood, 
and fill the fireplace at the first feed, and the crackling 
of that one fire will warm your heart, and be sutfiment 
to heat the brickwork in less time than I take to write 
out my idea of a comfortable fire on the spur of the 
moment. I, too, lived in Herefordshire, and fired away 
as if I had an oven. One year I cut down two acres of 
Apple trees there to burn in the furnaces of hothouses* 
and the old women predicted such a death for me, for 
cutting off so much of the “ mercies of life”—so many 
hogsheads of cider, their favoured beverage—as King 
James’ Privy Council prepared for the covenanters who 
murdered Bishop Sharp, of St. Andrews, if not a worse 
fate. Yet, without the Apple trees aud the large fire¬ 
places, the plants and forcing of that winter with me 
