2065. The first permanent plant-houses were merely chambers with opaque roofs, and only rather more glass windows than ordinary in front. In fact, houses of this description were frequently used as banqueting rooms, when the plants were placed in the open air during summer, as in the old orangery in Kensington Gardens, Houses with opaque roofs, though totally unfit for plants during the summer, are still found in many parts of the Continent, especially where they are wanted principally to afford a shelter during the winter months; as it is found extremely difficult to protect plants from the severe cold in the northern parts of Europe when the roof is entirely of glass.
