50—1846.] 
THE GARDENERS' CHRONICLE, 
821 
publie ata meeting in Regent-street, and pronounced “a 
boon to horticul " It was advertised, and the sale 
commenced, the writer of this placing a notice in your 
columns that the maker was no horticulturist, and that 
would answer any inquiry. Such is its history, and 
as Simmons acted on my advice in its connection with 
the gardening world, all lack of rule, &c., lies at my 
door. I was perhaps wrong in supposing that so simple 
an inst: could be misund d. I thought that 
as every one saw a thermometer rose with heat and fell 
with cold, and observing it formed a standard for him- 
Self at which to keep the temperature of glass erections, 
S0 he would find that this instrument indicated a low 
number with wet, and a higher one with less moisture, 
and making himself acquainted with its action, would 
forni a scale from his experience, Nothing would have 
been easier than to have printed a scale at which to 
keep buildings ining different descriptions of plants, 
but as we had but limited experience it would not have 
been honest, and therefore was not to be thought of. It 
was in fact commended to the observant, scientific hor- 
tieulturist, for him to mark and learn its only character ; 
at kept from being wetted or exposed to the sun it 
would give the amount of moisture present in any 
building in which it might be placed. I will conclude 
this letter, only adding, that with my intelligent gar- 
dener, Mr. Dobson, it has been most warmly welcomed. 
He has observed and used it as a guide in the Orchid 
heuse as much as the thermometer. Next week I will 
give figures and directions deduced from observations 
nowin course.—“ Beta’s” instrument is deranged. It will 
be exchanged free from all expense on application to 
Simmons,— E. Beck, Worton Cottage, Isleworth. 
Copings for Walls.-—That copings are of very con- 
siderable service I have not a moment’s doubt, but the 
nature of their services has lain under much misappre- 
hension. I am inclined to think that a majority of 
Persons view them in the light of mere blossom pro- 
tectors,whereas, in fact, they afford little, if any, protec- 
ion in this respect. Their real service, when suffi- 
ciently large, is of a twofold character, viz. :—the acce- 
erating an early growth in the early part of summer, 
and the thorough maturation of such growth in the 
autumn. To be guarded, however, in my obseryations, 
by early growth I do not mean causing the trees to bud 
earlier, but rather exciting the young growth, when it 
has fairly commenced, to proceed with greater freedom 
and rapidity. On the latter circumstance depends, in 
no mean degree, the preservation of the tender growth 
from the attack of insects, more especially in the case 
of Peaches and Nectarines. This principle is fully re- 
cognised in agriculture in the case of the Turnip crop, 
and why not in gardening? The benefits of coping in 
September and October are perhaps even greater still, 
and I think it would not be asserting too much to say, 
that at that period alone, in effect, they add a fortnight 
to the length of our summers ; or, in other words, they 
produce results equivalent to a fortnight’s fine weather. 
The rationale of their operation is, I suppose, by the 
interception of radiation; be that as it may,a wall 
with a good coping will be found warmer after sunset 
for some hours than one without a coping. The objec- 
tions in point of exeluding the dews and rains are, I 
conceive, of no weight, as it is quite certain that first- 
rate fruit is, and has been, produced under copings. 
For my part, I am disposed to look on a wall wet with 
rain in the summer as a disadvantage rather than 
otherwise, such being a robber of heat, which can ill be 
spared, more especially in Peach walls. For this reason 
Tam decidedly opposed to so many ablutions with the 
garden engine, unless applied early in the morning ; 
more mischief is occasioned by this work than people 
commonly imagine. There are ample means of keeping 
trees clean without robbing them of one half the bene- 
fits of a wall. With regard to the width of the coping, 
I think that from 7 to 9 inches at least should be pro- 
vided, and if twice that width in the months of April 
and May it would be a benefit. One half of this entire 
width should be movable at pleasure, and might be 
composed of boards on brackets. With copings of 
about 7 inches, and trees planted on platforms, of stiff 
loam only, a foot in depth, Peaches succeed here admi- 
rably ; the wood is probably as perfect as in the native 
country of the Peach. Whatever width be adopted, it 
should by all means be wide enough to throw the drip 
beyond the leaves—R. Errington, Oulton Park, 
Cheshire. 
Polmaise Heating.—Having visited Nutfield for the 
purpose of seein; the model erection, Mr. Meek very 
kindly explained everything ; and I must confess all 
was very different from what I had expected. The 
Cucumbers alone told me that it is an excellent system, 
and I am convinced that Pines will grow beautifully, 
planted out over the chamber—the air being so nice 
and soft, and the motion of the leaves showing the 
system to be more like nature than any other yet intro- 
duced. Polmaise being so simple and economical, I am 
certain it will soon be more valued than at present ; for 
it only requires to be well known to be duly appreciated. 
—A Practical Man, Bognor. 
Walcheren (Cauliflower) Broccoli.—Your columns, 
from time to time, have advocated the superiority of 
this variety, which in its true state is really excel- 
lent. Yet it too frequently occurs, that after a 
valuable vegetable has become generally known 
and appreciated, and large quantities are demanded, 
People are taken in with worthless sort in- 
stead of the genuine article. Last spring I procured 
seeds of the above; they have grown to an immense 
size, and formed large heads of little or no worth, 
merely a bunch of hard sprouts, when eooked worse by | 
far than a Scotch Cabbage. is is waste of time, 
ground, and money, and you have disappointment into 
the bargain. The next procedure is to have recourse 
toredress. In the first instance, the individual that 
sent them out will satisfy you so far by telling you they 
come from such a large dealer ; that large dealer states 
he procured them at a first-rate establishment, where 
particular care is always taken to have the article 
genuine, and so they go on, and no more can be made 
of the affair. —4. A., Bishop’s Auckland, Nov. 30. 
Soil for Pine-apples.—Sixteen years ago I was fore- 
man to a gardener in the north of England, who was 
then considered to be a first-rate Pine grower. 
soil used by him was loam, leaf-mould, sheep dung and 
soot, in specified quantities, mixed well together, and 
run through a coarse sieve ; the fine siftings were used 
for potting. “I at length left and went to a nobleman's 
garden near London, where a large number of Pines 
were grown, and the prevailing idea at the west end 
then was that Norwood loam was the only suitable soil 
for Pines ; on going to the east end of London, it was 
there positively maintained that loam from Wanstead 
Flats was indispensably necessary. Afterwards I went 
to a situation which for two years previously had been 
entrusted to the care of a garden labourer ; the houses 
were in a bad state, but to my surprise the Pine plants 
were the best I had ever seen, with fruit equally re- 
markable. On inspection I imagined the cause to lie 
in the soil—a just conclusion, as I have since proved by 
always using that kind of material; it was the very 
same sort of soil as is so successfully used at the pre- 
sent time by the French growers ; it was the top spit 
of Bagshot Heath, and being naturally well mixed with 
silver sand and laid in narrow ridges for 12 months, 
exposed to the weather, it bade defiance to even bad 
management.—D. R. 
Polmaise Heating.—In my last communication I 
promised to give further particulars, and a plan of my 
cheap method of heating by Polmaise; but subsequent ex- 
periments have so altered the lending characters of the 
system, that it would have been improper to have done 
so. In my first application of the system my drains 
were very small, consisting of drain-tiles (such as are 
used in draining land) laid double. In my interview 
The | b; 
| fire, and getting the house in fair order. I must here 
beg to call to your recollection the large volume of air 
I had to warm, viz., about 50 feet long by 22 feet wide, 
12 feet high, span roof, and upright sashes, glazed to 
within eight inches of the ground. Moreover, the roof is 
glazed with small glass four inches by three, and the 
laps not puttied; the uprights are glazed with 
8i by 7i sheet glass. At 7 o'clock the external ther- 
mometer stood at 26°, the internal at the most ex- 
posed end of the house, 39°, at the middle of the house, 
over the front trellis, and opposite the furnace, 40°, 
and 44° at the north end, where it joins to my forcing 
house, the thermometer in which stood at 50°, heated 
y the tank system. I then eut off one half of my 
drains close to the air chamber, securely closing the 
ends where I had cut them off; those drains commu- 
nicated exclusively with the sheltered end, thus admit- 
ting a portion of the air of the house to enter the air 
chamber immediately. I left the house in that state 
for an hour. "The thermometers then stood as follows : 
—external, 24°, internal exposed end, 40°, middle, 40°, 
sheltered end, 44°. My experiment had so far sue- 
eeeded to my wishes. I then cut off all the remaining 
drains, and again left for two hours. The thermometers 
then indicated, external, 20° ; internal exposed end, 
40? ; middle, 40° ; sheltered end, 449. At 12 o'clock 
I registered the following report :—external, 18° ; 
posed end, 40°; middle, 40°; sheltered end, 43°; 
forcing house adjoining, 47°. I then made up my fires 
and retired to rest; at half-past 6 I paid them another 
visit, and found everything satisfactory, as the following 
registration will testify :—external, 24° ; internal ex- 
posed end, 39°; middle, 40? ; sheltered end, 42? ; 
forcing house adjoining, 49°, and nothing required for 
the fires. All this was done at the expense of less than 
a bushel of coke. Some recent experiments have con- 
vinced me thattheabove diff in the perat f 
the extreme ends were caused, not by any irregular dif- 
fusion of the heated air, but by radiation from the hot- 
house; for having suspended another thermometer 
not more than six inches from the one from which the 
above registration was taken, it showed a di nce of 
3° in favour of the uniform temperature of the house, 
the one hanging against the glass of the forcing-house, 
g 
the other on the wooden upright. Having in the fure- 
Red 1 
with Mr. Meek, and also in a ; qi 
tion from him, he suggested that the cause of failure 
was partly in the size of the drains, and partly in their 
inclination being slightly upwards, instead of having a 
descent to the air-chamber. The first idea I did not 
entertain ; for, aecording to the laws of pneumaties, the 
air would flow as freely through a drain of 3 inches as 
through one of 3 feet; and also the colder the air, in 
proportion to the heat of the chamber it had to traverse, 
the more compressible it would become, and the more 
rapid its motion. I therefore threw away the idea that 
the drains had anything to do with it, further than pro- 
viding a sufficiency of air to the chamber. The second 
suggestion, viz., that of giving the drains a descent to 
the chamber, I could by no means accomplish, unless I 
made the drains above the level of the floor of the 
house—a most unsightly arrangement. My stove could 
not be sunk lower, from the certainty of being inun- 
dated by every heavy rain. My attention was therefore 
directed to the raising of the cold air from the drains. 
After a very careful consideration of the laws of gravity, 
I came to the conclusion that the cause of failure was 
the extreme nicety of the balance of atmospheric 
pressure on the mouth of the air-chamber, and the 
mouths of the drains ; for although I had an intense heat 
in the air-chamber, it could only escape by radiation 
through the upper surface of the iron plate which formed 
the top of the oven ; consequently no action could pos- 
sibly take place. To destroy that equilibrium was my first 
object. As I could not lower the drain, I therefore raised 
the mouth of the air chamber about two feet. This gave 
me an instantaneous and very strong current of air 
from the chamber through the drains. Having thus 
far accomplished my object, I turned my attention to 
Mr. Meek’s first suggestion, viz., the size of the air 
drains, I took them all up, and gave them an area of 
three times the diameter they had at first, but could 
not find any difference in the flow of heated air from 
the chamber. This brought me back to my first con- 
clusion, viz., that the size of the drains was not of 
much importance. After carefully considering these 
results (and they spoke volumes) I came to the con- 
clusion that the drains were useless, nay worse, for they 
only involved an expense and trouble, that would in 
many instances preclude the use of Polmaise altogether. 
The more I thought upon the subject the stronger was 
my conviction that drains were useless, and the more I 
felt determined to try and do without them. I felt 
eonvinced that the heated air would diffuse itself with 
equal rapidity over the whole building, and by that 
immutable law of nature which suspends the mercury 
in the tube of the barometer and raises the water from 
the well, and which compels the lightest particles of any 
fluid to ascend, and the heaviest to take their place ; 
that as it parted with its caloric it would fall down and 
traverse the floor of the greenhouse, and of necessity be 
drawn again into the heated chamber, to be again distri- 
buted over the whole house. These opinions were 
gthened a i had with one of 
Nature’s self-taught philosophers who chanced to call 
upon me, but who did not leave his address, or I should 
have felt a pleasure in naming him. Having fully made 
up my mind, the weather on Thursday last promised to 
be all I could desire, I therefore, in the afternoon, 
going exp p ly set aside the necessity of 
applying drains to the heating of buildings on the Pol- 
maise system, at all events to a limited area, and I have 
the faith tothink to rather an extended one—for of course 
there are and must be limits to everything,—1 deem 
it a duty which I owe to you, as the unflinching advo- 
cate of the system, to lay before you the result of these 
experiments. Polmaise is now only a furnace, an air- 
chamber with an opening into it close to the floor of 
the building, and with a raised orifice of from 
two to three feet to admit the heated air into the 
building. Can anything be more simple? In 
order to set at rest, and in some m to antici- 
pate enquiries as to the power of di g heat by 
Polmaise without the drains, the follo <periments 
will, I think, be conclusive :—I procure thermo- 
meters, placed them together, and finding they exactly 
agreed, I placed three of them along the highest point 
of the roof of the greenhouse (one at each end and one 
in the middle) ; one was placed over the front trellis, 
in the position it occupied in the previous experiments ; 
one was placed on the floor of the greenhouse, and one 
2 feet below the level of the floor, in a large cistern that 
I had emptied for the purpose of experimenting. With 
avery slight fire I obtained the following results: at 
the highest elevation the thermometer stood at 48° ; 
second, 44° ; on the ground, 44°; and at 2 feet below 
the level of the floor, 43° Fahr. This registration was 
taken about 8 o’clock last night ; 12 hours afterwards 
the thermometer indicated the same.—4d. Kendali, 
Queen Elizabeths Walk, Stoke Newington, Dec. 9. 
[What will the opponents of Polr say to this? 
Stoke Newington is not so far off that people cannot 
see for themselves. ] 
Vine Pruning.—l am induced to make a few re- 
marks on Vine pruning, in consequence of the disap- 
pointment expressed by some who have been at great 
expense with houses, and have no adequate return of 
produce. There is, perhaps, no fruit requiring arti- 
ficial cultivation that will give evidence of good cultiva- 
tion more jthan the Vine and vice versa. Pruning 
should be performed as early as possible after the 
leaves have fallen ; otherwise the Vine is to some extent 
deprived of organisable matter, which by early pruning 
would have been stored up in the remaining parts. 
Where the “ spur” mode of pruning is adopted, and 
for general purposes it is undoubtedly the best system, 
it is preferable not to prune back the wood of the pre- 
sent year to one eye, as is usually done, but to leave a 
long spur of four or five eyes ; the eye or bud nearsst 
the base or old stem is in all cases to be retaine “i, in 
order to produce the next year's wood; but it fre- 
quently happens that the base bud does not show fruit, 
or if it does, often not so promising as those further 
from the base ; if it promises well, it should be retained, 
rubbing off the remainder, which may be done at a very 
early stage of growth ; in fact, the sooner the better 
when it can be seen to which buds to give the prefer- 
ence. The long spur, divested of buds, will contribute 
its portion of organisable matter to the retained bud or 
buds, asthe casemay be; and should the base bud be fruit- 
less, still it must be retained ; and invariably some of the 
buds placed further from the base show fruit ; retain the 
best, together with the base bud, and at every spur en- 
fo} 
about three o'clock, prepared for action by lighting the | courage this growth only. As the growing season ad- 
