CONSERVATORY, properly so called, is a building heated by artificial means, having its whole southern part closed by large glazed sashes, which may be opened or shut at pleasure. Its floor is generally of stone, and a part of it is occupied by a stage on which plants in pots can be placed. Plants when in a growing state require an abundant supply of light : a conservatory is ill calculated, on account of its solid roof and sides, for the ad mission of light, and consequently a conser vatory is not suitable for plants in a growing state ; but plants when torpid, as in the winter season, require a very moderate supply of light, and this a conservatory is sufficiently calculated to admit.
A house of this kind is best suited for gar dens of considerable extent, where a large number of plants is required during the sum mer for the ornament of the flower garden - and shrubbery. Under such circumstances the erection of conservatories is the cheapest, ? the most efficient, and the most ornamental mode of preserving in a healthy state during 1 winter not only oranges, myrtles, and similar , plants, hut in general all the species which are natives of countries that, without expe , riencing severe frost, are cold enough during winter to suspend the vital energies of vege tation.
, A most important change has recently been introduced by Mr. Paxton in the principle of ' construction in conservatories, by the substi tution of iron and glass for brickwork. The Duke of Devonshire's magnificent conserva tory at Chatsworth, planned by Mr. Paxton,
is composed entirely of iron and glass. The length is nearly 300 ,feet, the width 150, and the height 70. It covers nearly an acre of ground, and has a carriage drive through it. The tubes for the hot water which regulate the temperature are six miles in length. A light but beautiful gallery extends round the upper part of the interior of the building ; while around the foundation is a tunnel, which gives access to the stoves and pipes.
The new Palm House in Kew Gardens is another beautiful example of the same kind of construction. It is 362 feet long, 100 feet wide by 66 high at the centre, and 50 feet wide by 30 high at the wings or ends. The curves which the glassy surface is made to assume are exceedingly graceful. A gallery runs round the lofty central portion, which is reached by an elegant iron spiral staircase. The glass employed has had a pale yellowish green tint imparted to it, to temper the heat of the solar rays. The structure is heated from beneath by stoves, the chimney of which, made somewhat ornamental, is at a consider able distance.
That triumph of constructive skill, the Palace of Industry in Hyde Park, was sug gested by Mr. Paxton on the strength of the experience which his • conservatory-building has afforded him ; and Messrs Fox and Hen Berson have worked out the idea with masterly results. This palace will be described in another part of the present work.