KITCHEN-GARDEN 
the different substances thoroughly mixed and 
incorporated. 
The proper temperature can be maintained 
in pits during winter much more easily than in 
the ridges; but on the latter, Mushrooms are 
still extensively cultivated by the market- 
gardeners near London. ‘Their mode of pro- 
ceeding is very simple. The ridge is formed 
of dung fresh from the London stables, and 
prepared by being thrown into long narrow 
heaps and turned as often as the centre of the 
heap becomes hot. It is ready for use after 
about a fortnight of this treatment. The beds 
are formed on a hard piece of ground, and are 
3 feet wide at the base, and are brought up to 
a very narrow ridge at top, to which the sides 
form a steep slope. The dung is made compact, 
and covered with mats or long litter to keep 
out the wet, and bits of spawn are inserted 6 or 
8 inches apart when the heat is declining below 
80°. The sides are beaten as closely as possible, 
and the whole is then covered about 2 inches 
thick with a fine adhesive loam, and beaten with 
the back of the spade, so that it becomes a com- 
pact casing to the bed. Formerly it was the 
practice to water this surfacing of soil and bring 
it to the consistency of mortar, but these plas- 
tered surfaces invariably shrink and _ crack, 
breaking the Mushroom threads wholesale. 
The heat is regulated more or less by the 
thicker or thinner covering of mats or litter, 
and if likely to become too cold, the bed is 
covered with warm litter. It should not be 
allowed to cool more than is proper, and then 
be warmed up by hot dung. Care must be 
taken to protect the beds from rain, for if they 
were allowed to get too wet the spawn would 
not run, and for this purpose long litter, mats, 
or tarpaulins are usually employed. 
Mushrooms can be obtained in abundance for 
a good part of the year from beds formed out- 
of-doors as above described, but the uncertain 
state of the weather occasions much more labour 
in regulating the covering than is required in 
growing them in a house where they are not 
exposed to extremes of heat and cold, and dry- 
ness and moisture. 
A Mushroom-house may either be span-roofed, 
or with a lean-to roof. A width of 10 feet is 
good, with a path 3 feet wide, and a bed 33 feet 
wide on each side. If the north wall were built 
hollow, it would the better resist sudden changes 
of external temperature, and the same would be 
the case with the roof if it were covered with a 
thick coat of thatch, either straw or heath; but 
thatch, except in particular situations, is un- 
VEGETABLES. 465 
sightly, besides being dangerous in case of fire; 
consequently slates will be chiefly employed in- 
stead, although in sunny weather they become 
hot, and transmit much heat to the interior. It 
will therefore be advisable, in the case of the 
Mushroom-house, to have a double ceiling. The 
interior should be filled up with brick shelves, 
having in front upright ledges 9 inches deep, 
and 2 feet ought to be allowed from the bottom 
of one shelf up to that of the one next above it. 
Moisture is readily diffused through bricks, so 
that if their outside is moist from vapour in the 
air of the house, their inner surface in contact 
with the materials of the bed will not be in- 
juriously dry. 
Where brick shelving has been tried the crop 
of Mushrooms has proved much superior to those 
on wood; and this being the case, the question 
is only one of expense as regards the first out- 
lay. 
Although for the greater part of the year a 
well-constructed Mushroom-house will not re- 
quire fire-heat, yet, in severe winters, it is neces- 
sary to have it at command. A little will suffice, 
— Sih 
(mere? 
ve i 
yg 
Fig. 1222.—Mushroom Cave in Paris. 
especially as the doors should be made to shut 
closely, and the windows ought to be furnished 
with close-fitting shutters. A small hot-water 
apparatus, with a flow and return 3-inch pipe, 
will answer the purpose. The pipes can be laid 
either in a channel under the footpath, where 
they can be covered with a grating or wooden 
trellis; or they may be placed along each side of 
the path, and saddled with movable evaporating 
troughs, made either of iron, tinned or gal- 
vanized, or of earthenware. If more vapour 
should at any time be required than will rise 
from these troughs, some of them may be re- 
