726 
THE GARDENERS' 
CHRONICLE. 
LÀ 
(Ger. 31, 
lower the temperature of the house, I should not have 
made these remarks but from a convietion that itis 
our duty, as practical men, to bear testimony to a system 
which, with a little variation, is one you have so ably | 
advocated in your columns from time to time ; with 
you it is known as Polmaise, but here as * Hazard's 
system of heating.” ^ When I first heard of Mr. 
Hazard’s i in warming horticultural! build- 
ings in the year 1843, both Mr, Mayes and myself were 
strongly opposed to the plan of heating by hot air, as 
we thought in the first place it would not be congenial 
to the growth of plants ; and secondly that no gardener 
would be enabled to keep anything like an equal tempe- 
rature in severe weather by such a system, and in our 
own minds we pitied those who were about to adopt it ; 
indeed, we felt so fully confident it would not answer, 
that whenever our opinion was required we invariably 
recommended the plan which we then considered best, 
viz hot water either in tanks or passing through 
pipes within the house, Judge, then, our surprise one 
frosty morning in the winter 1844-45 when on visiting 
for the first time the stove-house at Somerset House, 
Clifton, heated by Mr. Hazard's patent apparatus, we 
found the temperature at 70°, although. the gardener 
assured us that he had not touched the fire since seven. 
o'clock the previous evening ; the plants were in a most 
flourishing condition, and far superior in health to.any 
in the neighbourhood. Being desirous of thoroughly 
testing the system we repeatedly called and also sent our 
foreman, and i iably found the p of the 
house from 60° to 70° during the coldest nights of. that 
most severe winter. After this satisfactory result we 
were desirous of trying the system in our own esta- 
blishment, and having at that time a house heated by 
flues we removed them and erected Mr. Hazard’s 
patented apparatus, with its vapour appendage, in its 
stead. The house is in an exposed. situation, has a 
slant roof with lights in front measuring 42 by 13 ft. in 
the clear. On each side andat the bottom of the house 
is a striking-pit, with slate bottom, leaving a 2 ft, wal 
down the centre ; the warm air passes in large quanti- 
ties under the pit, which forms a, good. buttom-heat 
and makes its escape into the house. through. ven- 
tilators at the sides in such quantities as the gar- 
dener may require. Since its introduction’ we 
have used this house for forcing flowers in winter, such 
Roses, American plants, Pinks, &c., &e;, and can 
confidently state that we have never had them so fine 
under any other mode-of heating, more particularly the 
es, which were exceedingly fine, many of the Moss 
producing from 20 to 25 flowers on each plant... When 
the forcing season is over we then fill the house mostly 
with Amaryllis to give them their summer’s growth. 
Amongst these we place specimen stove plants, such as 
Allamanda, Dipladenia, Ixora, Pavetta, Clerodendron, 
Turnera, Inga, &c., all of which flourish and produce 
abundance of flowers, far finer than in our other 
houses heated on the old principle of steam, fire-flues, 
&e. We also find some Orchids much improved since 
they were removed into this house, especially Cattleyas, 
of which we have now a handsome specimen of C. in- 
termedia in fine bloom, and which has been-so for these 
last six weeks. We have always been enabled to keep 
the house at an uniform temperature of from 60° to 75°, 
and the fire requires attendance. merely night and 
morning ; the cost of fuel does not exceed 3d. per day. 
Such is our good opinion of this: system over all others 
that we wish the whole of our houses were heated) as 
this experimental one is. We shall be happy to show 
it to any one who may wish to inspect it—Garaway, 
Mayes and Co., Durdham Down Nursery, Bristol. [If 
e will favour us with a plan of this house, and of the 
eating apparatus, not including the details of the stove, 
we will publish it.] 
Culture of the Pine-apple.—Some inquiry having 
been made relative to remarks on this subjeet which 
appeared in our Calendar of Operations, it was sent to 
the writer of the Calendar, and. the following) is his 
ly :—* The observations. in the Calendar of Oct. 10; 
ending ‘these things will ere long be better under- 
stood, were intended to refer to the unwieldy character 
of the crown in many instances, They will apply, how- 
ever, to the whole course of Pine-culture, as it has been 
Carried on in a majority of cases for the last 20 years. 
Your correspondent quoting Mills, Knight, Barnes, &c.— 
i habs T EK ande e EE decks 
on the contradictory character of his extracts with 
regard to the use of bottom-heat. I beg, however, to 
say that the chief contradiction lies between Mills and 
Knight, and that this is more apparent than real. Mr. 
Knight having so frequently witnessed the folly- of 
enormous and unnatural bottom-heat, is led in the 
course of his remarks to repudiate it altogether—that 
is to say, to deny the necessity of using a fermenting 
body beneath as a medium. Now, be it remembered 
that Mr. Knight gave little air and kept very high tem- 
peratures, especially when much solar light existed. B. y 
means he obtained just what exists in nature—an 
advantage of a few degrees in the average of the bot- 
iom-heat over that of the atmosphere. Therefore it 
appears Mr. Knight did not deny the propriety of bot- 
tom-heat, but merely the capricious means by which it 
is generally obtained. Mr. Hamilton, after long prac- 
tice, during which he has. met with extraordinary suc- 
cess, approves of what is termed a. very moderate 
amount of bottom-heat ; about 80? in the summer, and 
not much more than 70° in the winter, Now, when we 
consider that an advantage of from 2° to 5° exists in 
ature in favour of the average temperature of the soil, 
as compared with the atmosphere ; and that the ave- 
rage atmospherie temperature for Pines in a growing 
state under glass in Bieton, is something like 70° to 
75°, or even 80°, we must come to the conclusion 
that Mr. Hamilton’s practice is perfectly intelligible an 
shelf inthe Pine stove. At the same time I put green 
tops of Potatoes, quite healthy, into both of the jars, 
and examined them on the 19th, when those in the jar 
it a} 
d 
natural Dr. Lindleyin his ‘Theory of Horticulture,’ 
p. 111, says—* The reason why it is necessary to plants 
in a growing state that the mean temperature of 
the earth should be higher than that of the air, 
is sufficiently obvious. Warmth acts as a stimu- 
lus to the vital forces, and, its operation is 
in proportion. to. its amount, within certain limits. 
If then the branches. and leaves of a plant are 
stimulated by warmth to a greater degree than the 
roots, they will consume the sap of the stem faster than 
the roots can renew it; and therefore nature takes care 
to provide against this by giving to the roots a medium 
permanently more stimulating, that is, warmer than to 
the branches and leaves." Thanks to the progress of 
seience, we have the tank in lieu of the old fermenting 
matter ; and when once this mode is well understood, 
and Hamilton’s plan adopted, it will, I make no doubt, 
set hundreds more growing the Pine-Apple: then will 
that observation be found correct, viz, ‘That it is 
easier to grow Pines than, to force a crop of young 
Potatoes, With regard to. the Hamiltonian mode, 
my persuasion is, that three-fourths of the gardening 
world eschew it on account of its simplicity. This may 
appear very strange, but if true, it clearly. points to the 
still immature state of gardening asa science or art. 
Your correspondent has a tank ; if he can rely on pro- 
ducing 80° in the superineumbent body, in the height 
of summer, and 75° in the depth of winter, my advice 
is, plant out as soon as possible: at 30 inches square 
apart. If the bottom is thoroughly drained, and. com- 
posed of very porous materials, it is ten to one they will 
last him his lifetime, with very little trouble. Before I 
conclude, I may perhaps.be permitted to observe that 
after all attempts to lay down principles for the proper 
regulation of bottom: and atmospheric heat, it will be 
quite obvious to those who understand first principles, that 
all these matters are merely relative, and must ever 
depend on the great leading principle of light, Of 
what use can surcharged vessels be without a. due 
amount of elaboration? The recognition of this principle 
will teach us to avoid many glaving errors,” 
Paulovnia imperialis (see p.693).—We have two long 
rows which were planted in the spring, when only aboutan 
inch high. The plants are now in fine robust condition, 
ranging from 8 to 10 feet in height. The leaves sent, it 
will be seen, are very fine, one of them measuring 
28 inches across. They have, however, suffered from 
the late stormy and almost incessant rains, We have 
little doubt that this very handsome tree will attain a 
degree of hardihood in our rather fickle climate which 
will render it an object of interest and desire.— 
H. Lane and Son, Great Berkhampstead, Oct, 94. 
Potato Disease caused by Atmospheric Influence.— 
The following facts. may throw some light on this mys- 
terious subject, and may induce somebody to investi- 
gate the elements of the atmosphere; for, although out 
of the power of man to alter natural laws, yet science 
may unfold some method of counteraetion, whereby the 
disease may be averted or mitigated to such an. extent 
that the Potato crop may again be cultivated as a. pro- 
fitable article of food. The following experiments were 
commenced. on the 3d of September, and examined. on 
the 13th inst. The Potatoes were all carefully selected, 
put into. garden pots, with their several mixtures, 
covered over with Moss, and then buried about 1 foot 
6 inches deep in the ground; except the Nos. 10 and 
11, whieh were laid on the ground. 
Basti Sept. 8. | Mixture, .. Oct. 19. 
1 [5 sound Potatoes ..) |p; All sound. 
2 f do., 1 diseased d Lime ...... ir 1 diseased. 
sound do. . eR, sound. 
4 do, 1 diseased. ... 5 PRET GOAL ss 15 do. 1 diseased. 
5 sound do. . il sound, 
6 |5 do., 1 dise: BOE ues. (found, 2 diseased, 
T7 |5s Toth; sound. 
8 |5 p 5 do., 1 diseased. 
9 "Ut CAI got worse. 
0 5 sound. 
Ty [Open air. .. 15 do., 1 diseased, 
i { Carbonate pan very. badly dis- 
of ammonia. ed. 
sed. Potatoes were all much worse. 
In experiments Nos. 2, 4, 6, and 8, where a diseased 
Potato was placed in the mids: sound ones, there was 
not the slightest indication of the disease being propa- 
gated by contact, except in No. 6 one Potato appeared a 
little dise«sed, but not at the point of contact with the 
diseased Potato ; sothat I imagine the disease had’ pro- 
bably commenced before I selected them, but had es- 
caped my notice; for I have had’ several instances 
quite as decisive as those now recorded, that contact 
with diseased Potatoes does not produce disease in. sound 
healthy tubers. Those in No. 12, which were mixed with a 
small quantity of carb, of ammonia,were all much diseased; 
which led me to suspect that the disease is caused: by a 
superabundance of ammonia (in some state) in the atino- 
sphere; and to test the of my suppositi 
I had recourse to the following experiments. On the 
13th inst. I put five sound Potatoes in a jar which had 
had earbonate of ammonia in it, and smelt very strongly 
of that substance : and also five sound Potatoes in a jar 
ofthe same size. I covered them both elosely up, and 
placed them in a Pine stove. They were examined on 
wi of ammonia showed. appearance of dis- 
ease, while those in the other jar discovered no observ- 
able difference. On the 22d inst., those in the car- 
bonate were all quite black, presenting just the same 
appearance as the Potato fields did in August and Sep- 
tember ; whilst the leaves of those in the sound jar only 
became of a yellowish hue, as might be expected from. 
natural deeay.—J. P., Oct. 23. [We are not able to 
answer the question in. your private letter]. 
Durham Potato Markets.—The market town of 
Hartlepool is now plentifully supplied with good Pota- 
toes ; the best at 3s. per bushel. ‘The Potato crop within 
many miles south and east of this port, with few ex- 
ceptions, can scarcely be said to have suffered from the 
prevailing disease, like many other parts of the king- 
dom.—Durham, Oct. 24. 
Wasps.—At the close of the fruit season, I sent some 
account of the way in which wasps hereabouts have 
been dealt with. I find that the number of nests 
taken from the 19th of June to the Ist of October, has 
been 88, but some remain which now will occasion no 
arm. The aecount of wasps taken in the glass traps 
(of which I send a specimen) consists of only 48 entries, 
and amount to 8634, on the average, 179 to each nest; 
but it is plain that the. memoranda have not been 
kept in a satisfactory manner. I have been present 
on few occasions, and I have particulars only of the 
two last nests; of the one taken in the daytime on the 
26th of September, the comb and grubs weighed. 44 Ibs.,. 
and the wasps taken in. the trap were 630; of the 
other nest, which was taken in the evening of the Ist 
of October, the comb and grubs weighed 3j lbs., and 
the wasps taken. in the glass trap were 540. This last 
nest was attacked. in the afternoon, but the squib having 
been put in a wrong direction from the nest, when the 
latter was uncovered. by the spade, the wasps were all 
alive; the nest was then covered with a thin clod, 
aud was left immediately, and the wasps made a. fresh 
hole by the evening, when they were easily taken. 
These two nests were not selected as large nests, but I 
went to them on account of the shortness of their dis- 
tance, and the latter was within a dozen yards of the 
garden, It is from a little attention to details, that 
you get at an estimate of the whole quantity of wasps 
produced in a.season in a certain district; within half 
a mile of an acre of walled garden, is it too much to say 
in round numbers, that you might take a quarter of a 
ton of grubs, and 50,000 wasps, more or less; and I ask 
what quantity of valuable fruits might they be supposed 
to devour and injure?—North Shropshire, Oct. 22. 
[These are very nice-glass traps, and are retailed by 
Gregory, of Oswestry, at 2s 4d. each.] 
Potato Disease caused by Atmospheric Influence, — 
The produce of some Potato shoots picked off by a 
neighbour and thrown away on a dunghill, where they 
lay two hours in the sun, was excellent in size and 
quality, though few, and none diseased. The produce 
of the Potatoes, their parents, was small, and diseased 
partially, The haulm of some shoots of All-eyes which 
had been forced in a box on a hotbed, was from 6 to 
7% feet long and single; crop diseased. A garden-light 
placed over two plants in a row of. Ash-topped Kidneys 
preserved them free, while the rest suffered. I took off 
the light, and the very next morning they were found 
spotted. in the leaf, and followed their neighbours. 
(They were very late for Ash-topped Kidneys.) This 
experiment was repeated with the same effect on a 
later variety immediately afterwards. Another light 
was placed at 6 in the evening on two plants of the 
Bread-fruit variety, and. taken off in the next day at 
12; being purposely left. off one night they were dis- 
seased before the rest of the crop. Did I communi- 
cate the disease? Every means was used by litte 
&e.. to i a sudden pherie shock.— 
G. K. F., Brigstock Vicarage, Thrapstone, Nor 
ampton, 
Manuring Potatoes (see p. 709.)—I am aware tha 
not only in 1845, but also in the present year, some 
crops of Potatoes on unmanured land have suffered ex» 
cessively, But they were generally of a late kind, or 
planted very late, [Those to which we alluded were 
Regents planted in the autumn of 1844.) To plant 
early, if the disease is to recur next August, is of the 
first importance, but'to avoid using abundantly what is 
called strong manure, and especially not to place it in 
the rows with the sets, is the second thing to be attended 
to. Last autumn I planted some Potatoes with the 
manure incorporated with the whole of the soil, and 
others with the manure ‘placed above and below the 
tubers. The former had not one decayed Potato in 50, 
the latter had at-least one in 10. I have also the expe- 
rience of more than 70 allotment tenants, every one of 
whom has this year had a spring planted crop of Po- 
tatoes. Some placed the manure with the sets, some 
in the whole soil, some both ways, and some purposely 
used no manure at all. The result has been decisively 
in favour of no manure, or mixing it with the soil, In 
one case the manure was spread over the whole ground, 
at one end of the rows, and at the other end placed 
with the sets in the trenches. The abundance of dis- 
the 17th inst. ; and those in the jar with the carbonat 
of ammonia were all showing symptoms of disease, 
whilst those in the other jar were quite sound. At the 
same time I took two of the diseased Potatoes out of 
the jar of carbonate of ammonia, and laid them on a 
