46—1846.] ‘TH 
E GARDENERS’ CHRONI 
CLE. 755 
ORTICULTURAL SOCIETY OF LONDON.— 
Notice is hereby given, that the EXHIBITION OF 
FLOWERS AND FRUIT, in the Society’s Garden, in the 
ensuing season, will take place on the following Saturdays, 
viz., May 8; June 19 ; and July 18 ; and that Tuesday, April 20, 
is the last day on which the usual privileged Tickets are issued 
to Fellows of the Society. 
EWARD, Esq., Young-street, Kensington, London. Amon 
them are many new and rare species scarcely known to Euro- 
‘peans, 
jurious as has been imagined. We admit that in 
spring, when the trees are in blossom, a wide coping 
may be useful ; but it ought to be temporary, and 
removable immediately after the fruit is fairly set. 
The accompanying sketches may serve the purpose 
of drawing attention to the subject. Nó. 1 we con- 
sider one of the worst copings for a garden wall 
that can be used, although, no doubt, excellent 
crops have been grown under such a structure. It 
is only met with in those districts where suitable 
materials for coping are either very expensive, or 
very difficult to be procured. The harbour it 
affords for all sorts of vermin is a great objection 
toit. For the same reason we are averse to re- 
cesses in garden walls, or to the training of trees 
coping, and may be either of stone or cement. The 
latter is the cheapest, and may be moulded to 
various forms by an experienced workman. If the 
materials are good, and the right proportions of sand 
and cement used, a coping of this kind will last a 
number of years, and successfully resist the action of 
the weather. Several moulds of the proper length 
and shape are first prepared. A certain por- 
tion of cement and sharp fresh-water sand are 
then wetted up and thoroughly incorporated, no 
more being made at one time than is considered 
sufficient to fill one of the moulds. The mould 
before using must be completely coated with oil, 
A layer of cement is then spread equally over it, 
into which two or three flat tiles are placed across 
and embedded. Some more cement is added, and 
The Gardeners’ Chronicle, 
SATURDAY, NOVEMBER 14, 1846. 
"Tur Corine or Garpen Watts is a matter of 
no small importance to those who desire to have 
fine wall fruit, and we should wish to see it taken 
up by correspondents of known practical ability for 
the cosi it deserves. It is well understood that 
the opinions of our best writers on gardening, from 
Mixer down to those of our own day, are at vari- 
ance respecting the utility of a wide or narrow 
coping; and it appears to us that an inquiry con- 
ducted by those who are capable of estimating the 
relative merits or defects of copings with different 
degrees of projection, would be exceedingly useful 
‘to the practical gardener, and interesting to the 
general reader. 
The main use of a coping is to protect the 
masonry from wet, and thereby enable it the better 
to resist the action of the weather. Were it not 
for a protection of some kind or other, newly built 
walls of the very best materials would soon be in- 
jured by exposure to the rain and frosts of winter, 
and fall into decay. For this reason a coping be- 
comes absolutely necessary; and such being the 
case, it is desirable to ascertain how far it is of ser- 
vice, or otherwise, to fruit-trees trained against the 
wall. 
'The object sought to be attained by planting 
trees against a wall, is to accelerate their growth 
80 as to enable them to mature their fruit-bearing 
wood, and afterwards, by the aid of the increased 
heat and shelter which the wall affords, to stimulate 
them to produce fruit that shall be of superior size 
and excellence. It is worthy of remark, however, 
that it is not always the trees most favourably 
situated in these respects that are the most healthy 
and fruitful; on the contrary, we often find them 
anore liable to disease and the attacks of insects. 
The cause of this may be sometimes owing to the 
soil, but it may possibly also proceed from the 
coping being made to project further than it ought, 
in consequence of which the leaves are deprived of 
the advantages they would obtain during the grow- 
ing season from the genial rains of the day, or the 
heavy dews of night. Some persons argue that 
unless the coping project so far as to carry off the 
drip from the trees, it is worse than useless. Others 
contend for a coping that shall only project one or 
two inches, and a few have advocated copings of a 
foot or more in width. Between these opinions it 
_is difficult for one who is not conversant with such 
matters to determine which plan is the best. Were 
he to adopt the practice usually followed in cases 
of doubt, and choose a middle course, it might 
happen that in doing so he had committed as great 
an error in fixing on a coping of six inches as on 
one a foot wide. 
No, 1. 
So far as our experience goes, we believe that 
the advantages of a wide coping have been much 
over-rated, and that the drip which falls on the trees 
om a narrow one is not by any means so in- 
oo 
$— 
between two piers, as shown in No. 2, especially if 
the coping isa wide one. Piers may occasionally 
be introduced for effect, but it is not desirable to 
have more of them in a garden than are necessary. 
Ten 
CC MR 
i 
No. 3 is the sort of coping in general use where 
thin stone or slate are plentiful. It answers the 
purpose effectually, if care be taken to keep 
the joints well filled with cement. A small 
groove underneath the edge would be an im- 
provement. In fact, no coping can be said to be 
complete without a groove, or some other contriv- 
ance to prevent the water from running down the 
wall. No. 4 is probably the most common way in 
which garden walls are coped, and when well done 
it will stand for many years, provided the bricks are 
laid in cement. To obviate the necessity of a groove 
in this case, the inner end of the bricks is to be 
bedded a little thicker, so as to cause them to in- 
cline outwards, but not so much as to be observable 
No. 6. No. 5. 
uniess to the practised eye. No. 5 is a mode of 
coping frequently resorted to where stone, or large 
slate, cannot be obtained, and answers very well. 
A thin wall plate of wood is laid along the edge, to 
secure the first row of slate. The middle of the 
wall is then ridged up with small pieces of stone 
and lime, into which the other rows of slate are 
made fast by small wooden pins, and the whole se- 
cured by a row of tiles on the ridge. The latter is 
sometimes coloured to resemble slate, or coated 
with.coal tar. No. 6 is one of the best forms of 
a couple of tiles placed lengthways along the 
middle, for: the purpose of strengthening it, as well 
as to save the cement. The whole is then filled 
with the temainder of the cement and smoothed off. 
In a few minutes it hardens sufficiently to be 
knocked out of the mould, and is afterwards placed 
on a level airy spot until it is dry. This was the 
late Mr. Arxrnson’s plan, and is that in use in the 
Garden of the Horticultural Society. 
To those who may be about to erect walls, the 
preceding remarks may be useful; they will, how- 
ever, be more so if they induce others who are 
better acquainted with the subject, to give us the 
result of their experience.—M. E. H. 
From the very beginning of the Pormarss dis- 
cussion we have been persuaded that in the com- 
mencement it would be attended by as much failure 
as success, and on different occasions we have said 
so. We were led to this conclusion by our know- 
ledge of the diffieulties inseparable from the first 
practical application of any novel theory, of the 
mistakes that unskilful persons necessarily fall into 
as to the theory itself, and of the numerous errors 
even now committed in the construction of hot- 
water apparatus by the most experienced men. In 
attempting to apply natural laws to any artificial 
purpose, it is necessary that all the conditions of 
those laws should be equally observed; it will not 
do to observe nine laws and neglect the tenth, for 
that tenth will interfere with the working of the 
remainder. It is, therefore, not with surprise, but 
with gratitude for the information, and admiration of 
its candour, that we have received, and hasten to lay 
before our readers, the following interesting letter 
from Mr. Mxrx:— 
“Tt has come to my knowledge this afternoon, from 
personal communication, that two separate parties, one 
near Coventry, the other near London, have each at- 
tempted to heat a house on the Polmaise principle, and 
have both failed, the one partially, the other totally. The 
former, a clergyman, had previously sent his builder to 
see the plan in operation at Nutfield ; the latter, a nur- 
seryman (th ghl inced of the of the 
prineiple), had carried out his own plans in a cheap 
form. They have each heated the chamber to a very 
high degree ; the former boiled the water in his tank, 
though there was a stratum of 8 inches of air between 
it and the plate ; the latter states that he could bake a, 
joint of meat. In the former ease there is a partial 
flow’of hot air, in the latter none at all; both cham- 
bers are air-tight as regards "the external air; in the 
latter case it is placed within the house, the doors only 
being external. It is therefore evident that in Polmaise, 
as in other things, there are certain conditions to en- 
sure success, and that if these are neglected, failure 
will be the result. And more valuable instruction will 
be derived from investigating the causes of failure than 
from studying the plan where successful. 
«c This afternoon the parties in question have both 
l ifffpected the hothouse at Nutfield; they have both 
gone away completely convinced that the plan can be 
made to answer ; they have seen a bottom heat of from 
80° to 90° Fahr.; they have both seen the action of 
the cold draughts and the hot upon the flame of a 
candle ; they have both satisfied themselves that in an 
extremely short space of time a puff of Tobacco-smoke 
blown into the most distant cold air drain passes to the 
hot air opening (on one trial almost instantaneously), 
the distance traversed being more than 32 feet, and 
this while the temperature of the house was at 709 
Fahr.; they saw a thermometer suspended in the hot air 
opening, where it returns to the house, standing at 
140° Fahr., and the leaves of a Cucumber plant, 4 feet 
above this, agitated freely by the motion of the air, and 
yet they have failed ; and I take this earliest moment 
to tell your readers of their failure, lest from motives 
of personal eonsideration towards myself they should 
not do so, and others should find themselves equally 
disappointed. ‘Now in the latter case of total failure, 
Ihave every reason to think the cause apparent, and 
it is the cause of so many failures in hot-water appa- 
ratus; the cold drain rises, instead of inclining down- 
wards ; and it is a singular circumstance, that the same 
party some years back erected a hot-water apparatus 
with the same defect, and the same results ; the circu- 
lation is necessarily impeded ; the cold drains are 
formed of draining tiles; these?lead into one drain 
whieh is also far too small (Ithink the main should 
