against extremes, as in the other case. A column of mercury, uóth a piston-rod and
machinery attached, has also heen used ; and a ring on a barometrical principle is suggested
by Sylvester. Tliere is also a very ingenious mode invented by Kewley. For
details at greater length on all the departments of the construction of hothouses, sec
R em arks, &c. 4to. 1817.
S e c t . IV. Mushroom-houses.
2180. T he mushroom-house is a genus of plant-habitation, which differs from the others
in requiring very little light. The simplest fonn of the mushroom-house is that of an
open shed or roof, supported on props, for thi-owing off the rain, and protecting fi-om
perpendicular cold. Under this, the mushrooms are groivn on ridges, covered by straw,
&c., to maintain the requisite temperature.
2181. T h e Jlu e d mushroom-house (fig . 653.) is an improvement on the shed, by being
better calculated for growing them in ivinter. Provided it be placed in a dry situation,
the aspect, size, propoi-tions, doors, or windows are of little consequence. To be sufficiently
warmed by one fire in winter, it should not contain more than 10,000 cubic feet
of air. As mushrooms will not thrive without some light, and at all events require air,
it ought to have two or tlu-ee windows or valves for these purposes.
2182. T h e G erm an mushroom-house (fig s . 654, 655, and 656.). It is a common practice
with German gardeners to grow muslirooms on shelves, and in pots and boxes,
placed behind stages, or other dark parts of their forcing-houses otherwise unoccupied.
(D ie tric h ’s G a rtn e rs L e x ic o n ; Ransleben’s B rie fe , &c.) This practice was carried to
Russia, and from Russia was brought to England by Isaac Oldaker, who thus describes
the sort of house adapted for the German practice : — “ The outside walls ( g , h , fig s.
654, 655.) should be 8^ ft. high for four heights of beds, and 6^ ft. high for three
heights, and 10 ft. wide withinside the walls: this is the most convenient width, as it
admits of a set of shelves 3^ ft. wide on each side ; and affords a space through the middle
of the house 3 ft. wide for a double flue and a walk upon it. The wall should be 9 in.
thick, and the length of the house as it may be judged necessary. When the outside of
the house is built, make a floor or ceiling over it (as high as the top of the outside walls)
ofboards 1 in. thick, and plaster it on the upper side (e e) with road-sand well wrought
together, 1 in. thick (this will be found superior to lime), leaving square trunks ( f ) in
the ceiling, 9 in. in diameter, up the middle of the house, at 6 ft. ¿stance from each
other, with slides (s) under them, to admit and take off air when necessary; this being
done, erect two single brick walls (v v ), each 5 bricks high, at the distance of 5^ ft. from
the outside walls, to hold up the sides of the floor-beds (a a ), and form one side of the
air-flues (i u, t u ), leaving 3 ft. up the middle ( t x t) of the house for the flues. Upon
these walls (v v ) lay planks ( t v ) 4^ in. wide, and 3 iu. thick, in which to mortise the
standards ( t k ) which support the shelves. These standards should be 3 | in. square,
and placed 4 ft. 6 in. asunder, and fastened at the top (h k ), through the ceiling.
When the standards are set up, fix the cross bearers ( i n, i n ), that are to support the
shelves (o o'), mortising one end of each into the standards ( i) , the other into tho walls
(n ). The first set of bearers should be 2 ft. from the floor, and each succeeding set 2 ft.
from that below it. Having thus fixed the uprights ( t k ), and bearers (¿‘ n ), at such a
height as the building will admit, proceed to form the shelves (o o) with hoards in.
thick, observing to place a board (d d ) 8 in. broad and 1 in. thick, in the front of each
shelf to support the front ofthe beds. Fasten this board on the outside of the standards,
that the width of the beds may not be diminished. The shelves being complete, the
next thing to be done is the construction of the flue (p, fig . 656.), which should com-
mencc at the end ( l ) of the house next to the door, run parallel to the shelves the whole
length of the house, and return back to the fireplace, where the chimney (s) should he
built: the sides of the flue inside to be the height of four bricks laid flatwise, and 6 in.
wide, which will make the widtli of the flues 15 in. from outside to outside, and leave a
cavity ( t u ,fig s . 654, 655.) on each side, betwixt the flue and the walls that are under
the shelves, and one ( x y ) up the middle, betwixt the flues, 2 in. wide, to admit the heat
into the house from the sides of the flues. The middle cavity ( x y ) should be covered with
tiles, leaving a space (A) of 1 in. betwixt each tile for the admission of the heat. The
top of the flue, including the covering, should not he liigher than the brick walls that
form the front of the floor-beds. The reason why the sides of tho flues are recommended
to be built stronger than usual, is, because they support the walk. The walk itself is
formed by three rows of tiles, the outside rows making the covering of the flues, and tliose
of the centre row ai-e what cover the middle cavity ( x y ), as above mentioned; the outside
cavities ( t u ) of the flue are left open, the tiles which are placed over the flues being
laid so as not to cover these cavities, which allows the heat of the sides of the flues to
rise upwards.” (O ld a k e r, in H o rt. T ra n s ., v o l. \\.)
2183. Mushroom s are g row n in the neighbourhood o f V ie n n a ; a n il fig . 657. shows a house,
of a very simple aud economical description, erected there. In this section, the inushi-ooms
ai-e represented rising through
a stratum of earth (a ), wliich,
657
with a substratum of dung
(h ), occupies the entire floor
of the house. The pathway
(c) is supported from the
floor by the posts, which are
rendered necessary at any
rate for supporting the front
shelf (d ), and the shelves of
the stage (e e e). Vmes may
be trained up the rafters;
there may or may not be a
small shelf, or a bracket, here
and there, for drooping plants
(/). About Vienna, houses
iu which mushrooms are
grown in this way are chiefly
employed for prolonging the
bloom of forced flowers and
shrubs, such as roses, lilacs,
bulbs, &c. The pots ai-e set
in saucers, to prevent any
water from dropping on the
mushrooms, and 6 inches
of hay are spread over the
latter, to keep them clean,
and prevent the escape of
heat. Tlicre is no flue ; but at each end is a small brick German stove, which is lighted
as often as may be necessaiy, to maintain a temperature during the night of from 45°
to 50°. The glass is covered by shutters every night, and the floor of the house is
from 3 to 4 feet under the external surface ; which, with the covering of hay, is
a great protection to the bed in which the mushrooms ai-e grown. The bed is made of
s s 2
« i i
I ■
l/l
*