644 
THE GARDENERS' 
CHRONICLE. 
[SEPT. 26, 
SSH 
4 " 
opinion, seems to be on the whole ir 
with it, This fruit has this year been extensively 
injured in the country round London, by a rot, 
which attacks the ripening Apple, and renders it 
unfit for use. Sometimes the leaves are blotched 
sometimes not. It is evidently, we think, the same 
as the disease of the Potato “ Apple,” or fruit, and 
in both cases is, as far as we have seen, unaccom- 
panied by fungi. It appears on the exposed side, 
where the fruit receives the most air; and there- 
fore, it may be said, is attacked by something in the 
atmosphere. But there is this difficulty in the way 
of admitting such an explanation: the supposed 
miasm ought to attack all Tomatoes in the neigh- 
bourhood of tainted Potato fields ; but it does not. 
Our excellent correspondent “ Quercus," than whom 
there is not a more close, shrewd, practical observer, 
finds no such disease in his Tomatoes; and we 
have lately seen beautiful samples of this fruit in 
the market of Boulogne, all round which place the 
Potato crops are blighted. The French peasants 
had not even heard of the Tomatoes being attacked. 
We respectfully present these facts to the consi- 
deration of those who are striving to find out the 
cause of the Potato disease. They not only must 
not be neglected, but no theory can be accepted 
which fails to include them in its scope. One thing, 
however, they seem to dispose of conclusively, and 
that is the notion that the Potato disease is to be 
kept off by regeneration from seed. Tomatoes are 
annually regenerated from seed, and Tomatoes 
suffer like Potatoes. 
THUNBERGIA CHRYSOPS. 
Carmine as most;of the Thunbergias are, the supe- 
riority of this species must at once be admitted by 
everybody ; the beautiful variety of tints exhibited in 
its large blossoms fully entitle it to the first rank in the 
genus. 
I had a few cuttings of it given me in May, 1845, 
which struek freelyin a brisk heat. After they were 
struck I potted them off into 3-inch pots well drained in 
a rich soil, and then placed them in a close pit heated 
with hot water. They grew very fast, and in August I 
repotted them into 5-ineh pots. By the middle of 
December I had the pleasure of seeing one of the plants 
in flower, andit continued to blossom from that time to 
April, daily expanding from 4 to 9 of its beautiful 
flowers. The other plants, from want of room, I was 
obliged to put into a common frame; but there they 
id not do so well. When placed in a warm and humid 
pl and not potted, the plant ceases tobe 
so exuberant, and it is much easier to keep it within 
bounds. I never eut any of the shoots, nor allow the 
plant to grow more than 2 feet high before I turn the 
shoot downwards, which checks the growth, and which 
I believe is the great secret of inducing the plant to 
flower. Itis a great mistake to keep repotting as it 
makes growth, if you wish to flower it. I know several 
people who kept repotting it until it was established in 
very large pots,and then all that could be said was that 
it had made a fine plant. But where were the blos- 
soms ?—not to be found. 
The plant which I flowered matured some seed long 
before it ceased to flower. After it had done flowering, 
i I repotted it into a 6-inch pot, and allowed it to re- 
1 main in a pit with some Orchids all the summer, and I 
D. have no doubt that it will flower again much earlier 
Dn next winter. I regret that some of the other species 
H were not in flower near it, for I do not suppose there is 
ii any probability of the seedlings raised from the old 
D plant sporting. As the plants quickly fill the pots with 
i roots, it will benefit them very much, when in flower, 
i to give them once a fortnight a good watering with 
i guano water, at the rate of 1 Ib. to 8 gallons of water, 
letting it stand until it is clear before it is used.— T. 
Davis, Colchester. 
POLMAISE HEATING. 
In a recent number I promised that I would endea- 
vour to prove that the advocates and employers of the 
Polmaise mode of heating have nothing to fear from the 
coming winter, by showing that the principle of Pol- 
maise is a compensating principle, so that, within cer- 
tain limits (depending on the extent of the means em- 
ployed), its results will rethain the same, whatever may 
be the external circumstances of heat or cold, and that, 
as a timepiece preserves its accuracy amidst cold and 
heat by means of the compensating pendulum, so will 
this system of heating necessarily retain a proportionate 
efficiency at all seasons of the year. 
our readers are aware that I have not built my 
heating apparatus after any pattern or design ; I knew 
that certain results ought to follow the use of certain 
means : I have employed the means—the result is what 
T foretold ; had it been otherwise, it would have proved 
vs which scientific men have given, as regu- 
iffusion of heat through the atmosphere, are 
r one fact upsets a thousand theories ; but 
fact and theory agree. Not one single 
expressed by those who have seen the 
tion as to certain facte, such as the flame 
wn one way by the cold air and carried 
the hot air ; the draught of hot air felt 
e or hand is placed near the hot-air open- 
rmometer, hanging in the centre of the hot 
ating a temperature of 90° to 100° Fahr.; 
the T moisture. What, then, 
the principle of this action ? and how is it a compensat- 
ing one ? why does the cold air flow out of the house 
and the hot flow in? Let us trace each step of the pro- 
cess ; suppose it is a December morning, the external 
air piercing cold, and hang a thermometer in the stove 
chamber and one in the honse ; they each indicate 32° 
Fahr. the fire is lighted, the iron plate feels the 
warmth, absorbs the radiant caloric, imparts it to that 
portion of air which is in contact with it ; air, like all 
other matter, expands when heated; expanding, it be- 
comes of necessity specifically lighter ; becoming lighter 
than that which surrounds it, it ascends ; and ascend- 
ing, it passes into the house: but what has become o 
the space it has left behind ? Nature abhors a vacuum ! 
The instant one portion or particle of air has moved, its 
place is occupied by another colder than itself; this, in 
its turn, is warmed, moves on, leaving its place to be 
again supplied ; and thus is a ceaseless current of air 
established from the house to the chamber, and from 
the chamber to the house, caused by the difference of 
density of the air in the two; which difference of den- 
sity itself depends on the difference of temperature, so 
that difference of temperature is the very element or 
principle of action in this system. While the stove cham- 
ber and the house are at the same temperature, 
whether it be 32? Fahr. or 100° Fahr. no circulation 
takes place; with equality all is at rest. But once dis- 
turb the equilibrium and the currents instantly flow till 
the balance be restored ! 
But this is not all; not only does the flow of the cur- 
rent depend on the difference of density or temperature, 
but the rapidity or velocity of the current bears an ewact 
proportion to that difference ; and here is that compen- 
sating principle which I have alluded to, so that 
supposing these currents travel at the rate of 10 miles 
per hour when there is a difference of 10°, they will 
not travel less than 20 miles when there is a difference 
of 20? ; nay, it is probable that the increase of velocity 
will be in geometric progression. ow, I ask your 
readers to reflect for a moment on the inevitable con- 
sequence of this law, as it concerns the maintenance of 
sufficiently high winter temperature in houses heated 
on the Polmaise principle; it must be this, that, pro- 
vided you can keep up the temperature of the stove- 
chamber, the temperature of the house will of necessity 
be kept up also; that the immediate effect of any 
attempt on the part of the external cold to lower the 
temperature of the house, will be only to induce a 
more rapid flow of the cold air to the source of heat ; 
and thus I consider the question of the diffusion of heat 
in winter is set at rest, the very velocity of its diffusion 
will be proportionate to the intensity of the cold! The 
power of diffusion being thus beyond all doubt, it only 
remains to provide sufficient caloric, or heat, to do the 
work. A bushel of coals ean ‘only, in the process of 
combustion, evolve a given quantity of heat; so that 
supposing a hot-water apparatus and a Polmaise appa- 
ratus equally absorbed every portion of the heat so 
given out, and conveyed it to the house to be heated, 
their working claims would be equal, the Polmaise still 
having the advantage in the first cost ; but it is not so. 
And here I must re o my own previous efforts ; 
your readers will possibly remember a Table of Tem- 
peratures published in the Chronicle, March 28, of this 
year (the accuracy of which has never been impugned), 
by which it was clearly shown that in all ordinary hot- 
water arrangements, and especially in those considered 
the best, there is great loss of heat; that, during one 
week in which the mean temperature of the air was 
40° Fahr., the mean temperature of the hothouse was 
60° Fahr., while the mean temperature of the stoke- 
hole was 80° Fahr. : and it would be no exaggeration 
to state that if these data had been taken in 1844 (when 
the external air was 10° Fahr., and the hothouse was 
with difficulty kept at a point of safety), that the stoke- 
hole temperature would have been much higher, not 
relatively but actually ; proving thus, that, as there is 
no such loss of heat in the Polmaise plan, its practical 
working will be proportionately economical. Natural 
wee heap in its first cost—cheap in its use ! what 
a contrast does it offer to the unnatural, unsound, ex- 
pensive, wasteful system of man’s devising. How 
various are the ways in which its path is proclaimed ! 
The peal of the thunder, does it not tell us with what 
fearful velocity cold air will rush into the rarified space 
eaused by the heat of the lightning! the land breeze, 
does it not prove how gently the air will travel from a 
cool to a slightly warmer spot! our.common practice 
of letting some fresh air in * at this door," and the hot 
air out “at that window" our very conversation, 
* mind, and don't sit in a draught”—all prove the un- 
doubted truth of Polmaise. 
A few words to the practical men, whose business it 
enis 
S 
pleasure, nurserymen for their profit, are all on the 
alert, and you will find it to your interest to lead the 
way ; above all, remember that this is an age when 
principles are more relied on than details. Horticul- 
ture and agriculture owe their rapid strides to this ; 
their advance is certain, they take Nature as their 
guide ; the means of diffusing heat by the circulation of 
the air itself will assuredly be brought to perfection, 
whether it be Mr. Murray’s, Mr. Hazard’s, or my own 5 
the principles are those of Nature ; you cannot prevent 
their triumph, therefore hasten it; remember, the 
principle is, to take the air you desire to warm over a 
heated surface.—2D. B. Meek, Holmesdale House. 
THE AMATEUR GARDENER, 
PREPARATIONS For WiNTER.— Although brilliant skies 
and a high temperature seem to make the mention of 
winter unsuitable, the Amateur must not forget that the 
middle of September scarcely ever passes away without 
sharp frosts, which give him a seasonable premonition 
of what is so soon to come. It has often occurred, 
within our memories, that the earth has been frost- 
bound in November to such an extent as to destroy 
everything tender or half hardy in the gardens. ^ A wise 
hortieulturist will provide against all such contingencies, 
and avail himself of the present favourable season, to 
guard against the ravages of a less propitious one. 
Nothing is more discouraging than to lose all our 
garden beauties by the winter's cold, so as to be 
obliged either to purchase or beg at the next 
spring. This mortification may be avoided by persons 
of the most slender means, and I shall consult the in- 
terests of a very large class of gardeners by givin 
the details of a practice by which the tender exotics 
which delight ‘us in summer may be preserved in 
winter. To professed gardeners this is a subject quite 
familiar, and demands from them the highest exertions 
of their skill. I do not write for them, but for ama- 
teurs of less experience, who are so often ready to give 
up their floral pursuits on account of their losses from 
cold, 
In a former paper I have given some account of an 
appropriate habitat for plants which it is desirable to 
preserve during the winter, A dry pit, with facilities 
for excluding frosts, is indispensable, when the ama- 
teur’s stock exceeds what he can conveniently proteet 
in his dwelling-house. Choose the highest and best- 
drained portion of the garden, and letthe pots, whenstored 
away, be placed with their tops a few inches below thesur- 
face of the surrounding ground. The ordinary covering of 
glass and a mat will suffice till hard frosts set in, when 
the sides of the frame placed over the pit should be pro- 
tected with a lining of dry straw, or other material, 
piled to the level of the lights. This, with an extra 
mat or two, wil defy all frost. Experto crede. But 
I must reiterate the necessity of giving air and light on 
every favourable occasion, and also of leaving the plants 
in darkness for a day or two whenever a thaw occurs. 
More plants are lost by exposure to solar light after 
frosts, than by any other means ; and it is a fact that 
cannot be too extensively known, that frozen vegetation, 
even in the case of tender exotics, will recover itself in 
most cases, if allowed to thaw in the dark. 
But what is to be committed to the care of a pit 
during the winter months? Probably many gardeners 
have scarcely thought of this yet, for it must be con- 
fessed great improvid is often ifested by those 
who profess and display great attachment to florieulture. 
Persons of experience will, before this time, have struck 
numerous euttings of those flowers which beautify their 
gardens in summer, such as Verbenas, Petunias, Helio- 
tropes, Pelargoniums, Fuchsias, &e. These, if not too 
large and too crowded, may be allowed to remain toge- 
ther in the pots or pans in which they have been rooted; 
they will keep better than if they are now potted sepa- 
rately, and space will be economised, If cuttings have 
not been made, they may be yet put in, running the 
risk of a failure on account of the lateness of the season. 
A gentle hotbed, with care, will even now secure roots 
to many cuttings, which may cautiously be hardened off 
before winter is confirmed. 2 
But presuming it is too late to attempt to strike cut- 
tings with the inferior means many amateurs possess, 
will call attention to what is now in existence in pots and 
in the garden, which may he preserved successfully for 
another year. Verbenas, which have been pegge 
down early in the season, will be found to have rooted. 
as you require of these rooted offsets, 
and let them be carefully potted and transferred at 
maller pots. 
d 
isto provide the means of diffusing p heat. 
Many years has your attention been engaged on a 
system unnatural, therefore totally erroneous ; you have 
used an instrument for a purpose for which it was never 
intended, and, with all your ingenuity, you have not 
broughtit to perfection (look at its waste), and you never 
can; scientific men have, with two or three brilliant excep- 
tions, as Rumford, Arnott, &c., left too much to 
yourselves, so that w inity of attention has 
been bestowed on mechanism, principles have been for. 
gotten. W time on a em which is 
erroneous in | ple 
that is sound ; let r siderations bind you to 
stand in the way of improvement ; increased consump- 
tion will more than compensate for diminished cost. 
Clergymen for their churches, gentlemen for their 
le 
exert your ingenuity on one | 
^ a 1 
borders, 
preserved. If you have many, you mus 
bloom of some of them, take them up at once, 
them be treated as above directed for plants in Tou 
But as there may be no injurious frosts for some uS 8, 
let the bulk of your plants remain where di ey 
are some time longer; indeed until frost touches 
them. .Caleeolarias, Fuchsias, Pelargoniums, hy hs 
hen be taken up, and the greater part of the d 
eut off. They may then be potted and put into, he p A 
With ordinary watchfulness your present stock may n 
manner be preserved, and delight you with the! 
ities next season. 
Searlet Pelargoniums are not 80 
‘many other greenhouse p! 
soon prosirated by 
ants are,and they 
