nOT-HOUSES.] 



PEACTICE OF HOETICULTUEE. 



[nOT-ilOUSES. 



cases, cold. In the tropics it is marked by 

 coolness and dryness, while the summer is 

 rainy and very hot; and in extra-tropical 

 countries the two seasons vary in their cha- 

 racter, in accordance with latitude and local 

 circumstances. 



The above is sufficient to lead to the 

 conclusion, that "the natural resting of plants 

 from growth is a most important phenomenon 

 of universal occurrence, and that it takes 

 place equally in the hottest and the coldest 

 regions. It is, therefore, a condition neces- 

 sary to the well-being of a plant, not to be 

 overlooked nnder any circumstances whatever ; 

 and there cannot be any really good gardening 

 where this is not attended to in the manage- 

 ment of plants under glass. Rest is effected 

 in one of two ways — either by a very con- 

 siderable lowering of temperature, or by a 

 degree of dryness under which vegetation 

 cannot be sustained." 



BUILDING OF HOT-HOUSES. 

 It is not necessary that we should recapi- 

 tulate here what has already been written by 

 many authors on this subject : it may be re- 

 marked, however, that the improvements in the 

 construction of hot-houses have by no means 

 kept pace with those which have, within these 

 few years, taken place in other departments 

 of gardening. In the Annals of Horticul- 

 ture, a writer observes — " There is yet much 

 which remains to be realised in the erec- 

 tion of bouses for the cultivation of plants, 

 not only as regards their number and di- 

 mensions, but also their arrangement and 

 details. We seldom see more than the same 

 kind of flat lean-to or span roofs ; the same 

 kind of formal stages where the plants are 

 grown in pots ; and the same kind of formal 

 beds when the latter are planted out in 

 borders of prepared soil. Even refinements 

 or elegancies of construction fail to invest 

 Buch buildings with any character of distinct- 

 ness or novelty, owing to the sameness or 

 monotony which forms the basis of the de- 

 sign." Since this was written, however, there 

 have been improvements in the construction of 

 hot-houses. This has, perhaps, been more 

 especially the case in regard to the roofs. 

 Among these, the ridge-and-furrow form, as it 

 is called, may be considered the greatest It 

 904 



was, in 1816, first suggested by the late Mr. 

 Loudon, and afterwards admirably worked 

 out by the late Sir Joseph Paxtou, in the 

 large house at Chatsworth and elsewhere ; but 

 more recently in covering in nearly twenty 

 acres of ground for the Exhibition in Hyde 

 Park. This, at the time, was the largest 

 building ever constructed of timber, iron, and 

 glass ; and showed, with the most perfect 

 clearness, the possibility of extending the 

 same description of pillared covering over any 

 space, however extensive. 



In discussing the merits of this subject in 

 his Book of the Garden, Mr. C. Mackintosh says, 

 that " the greatest advantage of a ridge-and- 

 furrow roof is, that any extent of area may be 

 covered without internal walls. Indeed, no 

 walls whatever are required, as the sides and 

 ends may be glass close to the ground— the 

 whole being supported on cast-iron tubular 

 columns, with cast-iron valleys, or gutters. 

 A good idea of the effect and practicability of 

 roofing over a whole garden, may be obtained 

 by a careful examination of some of our 

 most extensive raijway stations — that at 

 Derby, for example, which, we believe, could 

 be extended over a hundred acr5*s, if re- 

 quired." 



We do not wish to enlarge upon this sub- 

 ject ; but it may not be amiss to give, in 

 Sir Joseph Paxton's own language, an ex- 

 planation of the principles of this improved 

 sort of roof. In a lecture which he delivered 

 before the Society of Arts, in London, he 

 says — " In the construction of glass- houses 

 requiring much light, there always appeared to 

 me to be one important objection. In the plain 

 lean-to or shed roofs, the morning and evening 

 sun — which is, on many accounts, of the 

 greatest importance to forcing fruits — pre- 

 sented its direct rays at a low angle, and, 

 consequently, very obliquely to the glass. 

 As, at those periods, most of the rays of light 

 and heat were obstructed by the position of 

 the glass and the heavy rafters, so that a con- 

 siderable portion of time was lost both 

 evening and morning, it consequently became 

 evident that a system by wliich the glass 

 would be more at riglit angles to the morning 

 and evening rays of the sun, would obviate 

 the difficulty, and remove the obstruction of 

 the rays of light entering the house at uu 



