GREEN-HOUSE, a building appropriated to the cultivation of such exotic plants as do not require much artificial heat, but cannot endure the open air, at least in the colder part of the year. The name is derived from the original use of such buildings for the preservation of oranges, myrtles, and other evergreens; the cultivation of heaths, pelar goniums, fuchsias, and the many other flowers now familiar to everybody, not having been then introduced. The first green-house of which there is any record was erected about 1619, by Solomon De Cans, at Heidelberg, to shelter orange-trees. The Chinese, however, are not unacquainted with green-houses, and it is not known how long this has been the case. The earlier green-houses were glazed only on the sides; glass roofs were introduced in the beginning of the 18th c., and the arched or cnrvifinear glass roof, still more favorable to the proper admission of the sun's rays, is an improvement which dates from the early part of the 19th. Heat was at first supplied. when necessary. by
hot embers pia in a hole in the floor, afterwards by furnaces in the greenhouse; flues, steam, and hot-water pipes, etc., are more recent inventions. See HoTuot-sE. As a green-house does not require artificial heat during summer, the roof is sometimes made capable of being then removed; more generally, many of the plants are carried out into the open garden. Air is freely admitted into the green-house in fine weather, even in winter, during the warmest part of the day, care being taken that the plants are not exposed to frost, nor to ungenial and chilling winds. Green-houses are sometimes appropriated chiefly to particular gGuera of plants, under such named as heathery, cam ellia-house, etc. According to the present use of the terin, a green-hbuse differs from a conservatory only in the plants being in pots, which are very generally placed on the shelves of stages, having a slope not very different from that of the roof.