HOTBED; HOT-HOUSE. A hot-bed is a heap of fresh stable litter in a state of fer mentation, upon which a glazed box is placed for the cultivation of certain plants requiring heat and moisture, in greater quantity than those agents exist in the external air, For the growthof cucumbers and melons,raising seeds of tender annuals, and of other plants, either culinary Or ornamental; hot-beds are a.dvan: tarteeasly employed. They may be iratious Substances, such''aS rotting dung; tan, leaves, or a mixture of these with moist litter ; izi short, any substance capable'of pro ducing and retaining fermentation, and which will of being built up so its to support a frame with sashes.• A hot-house is a 'structure in which exotic plants • are cultivated under circumstances approximating as closely as possible to those under which they naturally exist; era is used for hecelerating the prochiction of floweii and fruits of _either, incligenrius:sir 'exotic plants. appropriated to the latter poses are very frelluenili termed forcing houses.
The,principles,by which the construction of hot houses must be governed have reference, to the three, great agents in vegetation-hcai moisture and light. There Must be Means for varying all these to a wide extent. ' With re to the means of supplying artificial heat, the old system of using brick flues is now ye Pidly heing saperseded by that of hot water. The glass for.admittinfi light to hot-hduses is found tolie.better fitted for its object if it has a slight green tinc •' et-houses may be classed under four' ferent heads, namely, the dr-Lstei;e, the cidnipp, stove, the. Park stove, and the forcing house. The Dry Stove; as the ,name .impliei,,is• used for the cultivation of 'plants which 0.1.4 require:
much water such as the different species of Cacti,,some Euphorbias,.and other succulents of like habits. • The,. temperature of such . a lionSe.sluring the winter months should never exceed 55° of Fehr, The A/mpg/ore requires treatment of an ofiposite.description, Instead abeing kept dry like the last,.its.citinosphere shquid. be, always excessiFelyjfmaid, except in the.wiincr season ; the temPerature is made . to vary from 55°M 79° accerdik the season. The beatitiful Palm .Honye afjCetv rhaY fie re garded as a damp stose:,_The ..B.ark Stove, when it is of large climensions;.consists of a pit in the middle Of the houseourroumied,by a brick wall, leaving as much roomLreund the , sides as will form a passage to walk in. The pit is filled with bark, and, after being allowed to sink a little and ferment, the pots-contain plants, are.phuaged more or less deep as prudence may suggest. The Forcing/reuse is a contrivance of frames and Pits, 'heated with dung, to accelerate the growth hnd matu ration of flowers, fruits, and vegetables, • Them are also hot walls, or walls with flues in '.them, constructed in cold 'countries, in order to afford warmth to trees placed against them. - One furnace is • allowed for l.eating about 40 feet of wall, that is, 29 feet on each Side place where the fire is situated. The flues on either side are made to take four courses, or two returns; the slrst course being it' little above the snrfuce of the ground, and the upper 11 or 2 feet below the coping. In stead'of flues, hot-water pipes might be intro duced into the cavity common hollow wall, a little above the level of the border. .•