MECHANICS 
yards in length and three in breadth, thought lie might 
contrive to heat it by fteam ; and that, if he could (uc- 
ceed, he fhould ever after fave the great trouble and ex- 
penfe of getting bark in the neighbourhood of Liverpool. 
In a few hours, in the prefence of two or three friends, 
he made a plan of the flues, arch, &c. according to the 
prefent method; and was then fo confident of its i'ucceed- 
ing, that he fent for workmen the next morning; and in 
a few days, under his dire&ion, the pit was altered and 
fitted for the fteam-method. 
Experiments .—Commenced on the 25th of April, 1788, 
by putting fome good melon-plants into three feet deep of 
ftrong melon-foil. The plants grew very well, and were 
remarkably ftrong and luxuriant, but fet no fruit till the 
35th of July ; they then produced an abundant crop, ex¬ 
cellent in flavour, thin-fkinned, and thick-flefhed. It is 
iiow r clearly proved, that their extreme luxuriance, and 
backwardnefs in fetting their fruit, were owing to the 
depth of the foil, as will be feen in the experiments of the 
following year. It holds good in the fruiting of plants in 
general. Trees planted in deep foil, particularly pear- 
trees, are along time before they fruit. 
1789. —Not aware of this, but fuppoling that laft year’s 
foil was too rich, I planted this year in the fame depth 
of a weaker foil, with good clay-marl, but lefsdung; 
thinking 1 Ihould prevent, by this mean, the vigorous 
progrefs of the roots : but, from the prodigious vege¬ 
tating power attending this method, the plants grew 
equally luxuriant. Still they had no propenlity to fet 
their fruit until about the fame time of the year : the crop 
was agSin abundant and excellent. It was no uncom¬ 
mon thing for the fruit to grow in clutters of two and 
three, fimilar to walnuts; and uniterfally each melon of 
the clutter ripened at the fame time, and came to its full 
growth. 
1790. '—As I now began to imagine that the depth of 
the foil occafioned the great luxuriance of the plants, I 
reduced it to two feet in depth. In confequence of this, 
the plants fet fooner, but tfcill late, and were too luxu¬ 
riant. They produced, however, a rnoft excellent crop, 
as well as in the former years. 
1791. —Being now convinced of the neceflity of not 
having the foil too deep, and wifhing to afcertain the bell 
depth,T filled the large pit with foil in fuch a manner as 
to have a regular Hope from end to end : the deeped part 
was two feet and a half, and the other one foot. The re- 
fult was curious and interelting; for the fruit in the 
different lights fet in regular fucceffion, week after week, 
tbofe plants fruiting firlt in the foil of one foot in depth. 
The crop was abundant; and on the deeped part of the 
foil every thing was nearly as in the former years. 
1792..—This year the melon-plants were planted in fif¬ 
teen inches of ftrong melon-foil, upon two feet of bark, 
that had been ufed two years before in the lame pit, to 
prevent the (team from a fling too powerfully on the foil, 
and to raife the plants near enough to the glafs. All 
now fucceeded well. The fruit fet as well as on bark or 
dung, but was infinitely more luxuriant and productive. 
During the laft five years, the fteam has been abundantly 
ufed in Mr. Wakefield’s vine-houfe, with a fuccefs beyond 
his expectation. The firft year the fteam was ufed, the 
vines were much more luxuriant, and grew at lead a 
month longer than formerly; to this circumftance the 
abundant crop of fruit the year following was in a great 
meafure attributed, as it afforded time, after the fruit was 
gathered, for the embryo fruit to form in the buds for the 
enfuing year. Till now, it has been found difficult to 
furnilh the plants with fufficient nutriment, both to ripen 
an abundant crop of fruit, and to fwell the buds to that 
degree which is requifite to fecurea good crop for the en¬ 
fuing year. Through a want of this power, it frequently 
happens that vines, as well as other plants, will not pro¬ 
duce abundant crops for two fucceffive years ; but, by the 
prefent method, Mr, Wakefield’s vines have produced. 
?£)5 
for the laft four years, fruit in the greateft abundance, 
and of the bell quality; the grape-berries being much 
larger than formerly, thinner fkinned, and better flavoured. 
But a fufficient proof that the vine delights in this at- 
mofphere is this, that, if fteam be fufficiently fupplied 
during the whole of the fummer, the leaves every morn¬ 
ing willi be pearled round the edges with drops of water 
exuded from the plant. This is frequently feen in every 
lioufe during the fpring, when the earth and the atmof- 
phere are charged with moifture ; for then vegetation is in 
the moll luxuriant 4 ftate. But this indication of vigour is 
never feen at any other feafon in the old method ; and, 
from the want of it, the red fpiders too frequently make 
their ravages ; though, when fteam is given in fufficient 
quantity, that deftruflive infeft is never l'een. 
Here follows a detail, from the diary of lord Derby’s 
gardener, of experiments made at a fteam-houfe, of a fi- 
milar kind, built by that nobleman at Knowfley. Thefe 
experiments were made on vegetables, fruits, and flowers; 
and the fuccefs was very fatisfaClory, fo much fo as to 
remind us of the remarks and prophecy of fir Jofeph 
Banks, which we noticed under the article Horticul¬ 
ture, vol, x. p. 417. But we muft pafs over thefe ex¬ 
periments, and conclude with a defcription of the fteam- 
houfe invented by Mr. Wakefield. 
Fig. 135 is the ground-plan, (bowing the direfliob of 
the flues, upon two of which, A, B, are placed flat cop¬ 
per pans, extending from C to D, three inches in depth, 
and made of thin rolled copper. Thefe pans are fixed in 
the brick-work, and Supported by flat iron bars under¬ 
neath ; are inclofed in the (team-vaults E, reprefented in 
the feilion of the houfe, fig. 136. and fleam is formed 
from water poured within them. The roof of the vault 
F is a perforated brick-arch, (fee fig. 139.) admitting the 
fteam through the tan or foil G G, which is placed upon 
the arch, after it is covered with finall dates or tiles, to 
prevent the tan or foil, in which the plants grow or are 
plunged, from trickling through the laid arch. The width 
of the foil-bed or pit is fix feet; the depth of the lleam- 
vault, E, is four feet, from' the bottom of the flue to the 
centre of the arch ; and the infide width of each of the 
flues, A,B, is fifteen inches. The height, from their 
bottom to the under fide of the copper pans, is twenty 
inches. Each of thefe flues has a furnace, H, H, at the 
oppofite ends of the houle; and the linoke pafles on 
through the back-fines I. 
There mull be a feparate furnace K, for the front flue 
L M, which flue is within the fteam-houfe, and more ele¬ 
vated than the arch F. Upon this flue is placed a flat 
copper pan, fimilar to thofe already defcribed ; this pan, 
extending from L to M, is covered with perforated tiles, 
fimilar to thofe ufed in drying malt, which affords the 
opportunity for pots of French beans being placed there¬ 
on. This fituation is peculiarly favourable to thefe plants ; 
and, at the fame time, permits a fufficient quantity of- 
fteam for other plants in the houfe to afcend through the 
tiles, from the water heated in the copper pan -beneath 
them. Where there is no front flue in a vine-houfe, it 
will be found very (erviceable to fix a fiat iron boiler at 
the back of the vine-houle, in fuch a manner that tire 
(team may pafs from it by pipes through the wall from an 
arch or cover made over the boiler. 
At N is a leaden pipe to convey the water into tire 
back pans below the arch : the other pans below are (ap¬ 
plied in a fimilar manner. At O there are fquare holes, 
which muft be left the whole length of the building, to 
allow fteam to mix plentifully with the atmofphere in the 
houfe. 
Fig. 136 is a feflion of the fteam-houfe: for references 
to the letters, fee the accounts above. Fig. 137- fliows 
the form of one of the copper pans, upon a larger fcale. 
P is the bottom of the pan ; Q, the edges placed within 
the brick-work. Fig. 138 is a teftion of the pan and flue, 
to lliovv the manner it is fixed in the brick-work, and the 
deptk 
