THE COTTAGE GARDENER AND COUNTRY GENTLEMAN, January 22, 1861. 
SMALL FORCING-PIT. 
I HAVE 15 feet long by 6 feet wide of pit-liglits that I wish to 
rebuild in a small forcing-pit for raising Cucumbers, to be heated 
with flues built brick on bed; the flue to be 1 foot from the 
front wall, to turn and come back 1 foot 6 inches from the back 
wall, and rising 4 inches gradually the whole way. Round and 
over the flues to be covered with brickbats with a layer of gravel, 
on that to be placed a layer of mortar to within six inches of the 
front wall. Between that and the wall I think of carrying a pipe 
pierced with small holes communicating with a flower-pot to 
supply moisture. Would air-drains be of any service in the 
front wall to warm the air as it rises P Would you tell me the 
lowest height the pit and flue may be, and whether the proposed 
plan will do ?—E. H. 
[Like some other correspondents, you say nothing of height* 
We presume your front flue is for bottom heat, and the back flue 
for top heat. If so, we say, Go on. If not, you must have open¬ 
ings to let up top heat at pleasure. The flues must be well built 
and brick on bed, if you admit heat from the covered-in part 
into the ah* of the house. The back flue would be as well to be 
the same ; but brick on edge would do if you did not water it. 
The plan of moistening the rubble is good, but the water should 
not go on the flue. The air-openings will be useful in early 
spring ; but even then a slight opening at the top must not be 
neglected in bright sun. The bottom of your pit should be 
30 inches to 36 inches from the glass, which will give you from 
15 inches to 18 inches for soil.] 
TURNING A GREENHOUSE-VINERY INTO A 
STOVE. 
We regret that the inquiry of “A Young- Subscribes,” was 
made too late to permit an answer being given in the Part for 
December. Unless in extraordinary cases, correspondents should 
not delay writing, and then make the request for an answer to be 
given in the next Number, as most likely that Number may be 
nearly in type before their inquiry arrives, and many inquiries 
seemingly simple require much consideration before a proper 
answer can be given. We should regret the delay the more in 
the case of our mechanic correspondent, were it not that the 
state of the weather must have prevented him doing much, 
whatever alterations he may have contemplated. 
The first thing that strikes us is, that there is force in the old 
proverb, “ Let well alone.” Such a nice collection of flowering 
plants, and a crop of Grapes from a small house, is highly 
creditable to any mechanic, and many would be perfectly satis¬ 
fied with it. As economy is an object, it is right to state, that in 
an average of seasons, a plant-stove will take three or four times 
the amount of fuel that a common greenhouse would do, though 
the labour of general attendance otherwise will, if anything, be 
lessened rather than increased. 
The second thing is, that three lines showing a section of the 
house and the position of the flue would have given a better 
idea of the circumstances than merely stating that the house is 
small, low-roofed, and heated by a flue on three sides, so as to 
command any desirable amount of temperature. Eor instance: 
Supposing the flue now enters at one end, goes along the front, 
and crosses at the other end, it might be possible to shut in one 
end so as to give bottom heat there if required ; or the flue might 
be returned along the back of the house, and a bed made over it 
where a foot or fifteen inches of tan would be very useful for 
stove plants at certain periods, though with plenty of moist heat 
the plants referred to will do admirably without bottom heat at 
all. A good strong flue in a small place is just as good for 
bottom heat as pipes or tanks covered. The heat, of course, will 
be dry, but it is an easy matter to make it moist enough by 
pouring water on stones near the flue, and not on the flue itself. 
Our correspondent will see that Mr. Allen has redeemed his 
promise; and for small places we have no doubt the little boiler 
will answer well, and it will be a little cheaper than the smallest 
conical and retort boflers, and will need less setting—in fact, in 
some cases might do without any setting at all, though heat 
would be lost. For such a house an amateiu* some time ago 
placed a common metal kettle that he bought for a few shillings 
over the flue, after drilling a hole near the bottom for fastening 
a one-inch iron pipe, and one near the top for a similar purpose, 
both leading into a wood tank two feet wide and four inches 
deep, and divided in the middle, except at the extreme end, and 
covered with house-slate. The kettle had a wooden bed bedded 
with red lead, for the tank was no higher, except by an inch or 
so, than the flow-pipes. If the kettle had been from one to three 
feet or more below the level of the tank, the top would have 
required to have been iron and securely fixed all round. In a 
similar case, both holes were made in the lid, the flow-pipe going 
an inch inside, and the return going down within two inches of 
the bottom of the boiler; but that did not act so well. It is 
always advisable for a quick circulation to keep the return-pipe 
cool. Such a kettle would do also by means of an open pipe for 
diffusing moist warm vapour in a bed of stones, clinkers, &c. 
In answering a correspondent recently, “ A New Subscriber’’ 
would see a mode by which his Vines could be protected during 
winter, and gradually brought forward before introducing them 
to the house. The modes of doing this may be greatly modified 
according to the object aimed at. In that case it was desirable 
to make a forcing and propagating-house in winter and spring, 
and yet not interfere with a fine crop of autumn Grapes. Our 
correspondent could do the same by having a temporary double 
front to his house, between which to keep the Vines and for¬ 
ward them a little before introducing the stems into the house. 
That time may be varied according to the time he wishes the 
Grapes to be ripe. However he may determine, the G ra pes 
should not be looked upon as a keeping crop, but one to be used 
as soon as ripe. Economy kept in view, we should prefer the 
Grapes to be tolerably early—say, the end of June or beginning 
of July; because if disposed to sell them, the value of the Grapes 
would be double or treble what it would be in September, 
and would return something for the fuel used. In the first 
season there could be no difficulty in raising the temperature 
gradually in January, and protecting and warming the roots at 
the same time. If the roots are very deep, the Vines will not 
force so well. 
Now, in the second year, this is how we would proceed. 
We will suppose all the Grapes cut by the end of August; 
then give the Vines all the heat and light possible in Septem¬ 
ber—at least for the first part of it, and keep the roots rather dry 
to harden the wood. Then, supposing you have no double 
front to your house, take the Vines out of doors and fasten them 
to stakes, letting them have all the sun possible. By the middle 
of October prune them and wash them, and protect from frost, 
By the middle of November protect the border with fermenting 
litter, and the Vines in mats may be laid on it. The weather will 
now be getting dull, and the front of the house may be reduced 
to 50° for a fortnight, the rest of the house kept from 5° to 10° 
warmer. Along the front of the house the Vines may be fastened 
longitudinally by the middle or end of November, or the same 
time in December, only giving them a temperature of about 50° 
where they are placed for the first three weeks, and then raising 
it gradually to 60° as they break. That may be the medium tempe¬ 
rature afterwards, and on to 65° when they are in bloom, and the 
increase in temperature will take place some time after the change 
of the day, and when a lengthened sun will permit of a higher 
temperature to the plants you cultivate. A month or so after 
the fruit was cut, the Vines would require to be again removed. 
The times of lighting fires, and giving over fires, must, there¬ 
fore, depend on circumstances and on the weather. Such 
plants as you allude to will not long flourish in a lower tem¬ 
perature than 55° at night in winter, with a rise of 5° during the 
day if cloudy, and 10° to 20° in sunshine. In starting Vines 
in such a house, by keeping the front cool—say to 50°, by air 
and moisture for a fortnight, and then raising gradually to 60°, 
the Vines may be broken safely. If this is not done until 
Christmas the sun will have gained considerable force by the 
time the Vines are in bloom; and the increase of temperature 
from 60° to 65° and 70°, will answer plants and Vines alike. 
After the Grapes are set 65° will be high enough for them at 
night, and so will it be for the plants. There may with pro¬ 
priety be a rise of from 10° to 20° with sun heat, provided a 
little air is given early. These indices are of more importance 
than telling when to discontinue firing. A fire may be more 
needed in July than in April, and the practice must correspond. 
It will be of importance in autumn to diminish moisture in the 
atmosphere and increase the light and heat from the sun to 
thoroughly harden the wood ; and that secured, the plants will 
stand uninjured a lower temperature in the first dark months of 
winter than they would do if more soft and spongy. 
If neither this mode, nor the one recommended for an early 
late crop suited yon, then we would advise keeping the Vines 
out, protected with calico, until the Vines began to break in 
