128 



HOTHOUSE-BUILDING. 



than metallic ones ; sufficiently light for 

 all useful purposes, if large squares of 

 glass are used ; and decidedly far more 

 easily managed as regards heating. The 

 only exception we can make in favour of 

 metallic houses upon a small or moderate 

 scale is, that the metal being capable of 

 being formed into curves without loss of 

 material, it is better adapted for curvili- 

 near houses than wood. We lately had 

 the satisfaction of seeing two magnificent 

 houses of wooden construction very much 

 to our mind, namely, that of Messrs Lu- 

 combe and Pince at Exeter, for the cul- 

 tivation of Camellias, 200 feet long, 22 

 feet wide, and 16 feet in height; and the 

 other, still more spacious, built a few 

 years ago by Asheton Smith, Esq., at 

 Tedworth Park, near Salisbury, 300 feet 

 long, and 140 feet broad — in itself a com- 

 plete garden under glass. The interior 

 contains two longitudinal beds or borders, 

 intersected by a circle of gravel in the 

 middle, and a transverse walk in the 

 centre of the house, while one of great 

 breadth passes down the middle from 

 end to end; there are also two narrow 

 walks on each side parallel with the sides, 

 and separated from them by a narrow 

 border. 



On the merits of metallic roofs, we 

 have the following very judicious remarks 

 by the editor of the " Gardeners' Chroni- 

 cle," vol. i. p. 57 : "The advantages of 

 iron roofs for hothouses are, that they are 

 more durable than wood, and allow a far 

 greater quantity of light to pass through 

 them than wooden roofs, the difference 

 being as 7 to 23, or even 30, in favour of 

 iron ; and this is a most important pro- 

 perty, when we consider that the healthy 

 action of plants is in proportion to the 

 quantity of light which reaches them. 

 The disadvantages of such roofs are that 

 they rapidly heat, and as quickly cool 

 down. They are, however, liable to sud- 

 den changes of temperature, which can 

 only be guarded against by great atten- 

 tion, which is expensive, and by a large 

 consumption of fuel. 



" We should say, use iron if you prefer 

 success and beautiful form to cost, and 

 can rely upon the attention of your peo- 

 ple ; but employ wood if you are obliged 

 to study economy." These remarks are 

 perfectly true so far as they go, with the 

 exception of the assertion of greater dura- 



bility, which is very questionable ; and 

 as to the vast difference in the quantity 

 of light transmitted, we think that very 

 much overrated, unless the talented editor 

 intends to contrast wooden houses of the 

 worst possible construction with metallic 

 ones of the lightest and best forms. 



All curvilinear houses should be of 

 metal, as the waste of material, in form- 

 ing them of wood, would be great. All 

 lofty houses, such as those at Kew, should 

 also be of that material ; but for houses 

 of moderate height, and for ordinary 

 purposes, we greatly prefer wood. 



It must, however, in fairness be ad- 

 mitted, that great improvements have of 

 late years taken place in the material and 

 construction of metallic roofs. The ex- 

 pense is very greatly reduced, and the 

 evils of conduction, both of heat and 

 cold, are somewhat lessened since the re- 

 peal of the duty on glass, by the use of 

 larger squares thus placed within our 

 power ; consequently much less surface 

 of iron is exposed, as rafters and the hea- 

 vier pieces are, or can be, entirely dis- 

 pensed with. Galvanised iron, if properly 

 manufactured, is less liable to corrosion 

 than the metal originally used, and anti- 

 corrosion paints greatly counteract this 

 evil. 



A more recent discovery, however, ap- 

 pears to claim some attention, namely, 

 the patent taken out by Messrs Grissell 

 and Redwood, "for improvements in 

 coating metals with other metals. The 

 patentees claim the use of borosilicate of 

 lead in a fluid state, over the surface of 

 melted copper or brass, or of certain 

 alloys in the process of coating iron by 

 immersion ; also the process of coating 

 iron with copper, by the action of fused 

 chloride of copper." — Vide Chemical Re- 

 cord. The more recent process of coat- 

 ing iron with flint glass, on Messrs 

 Johns and Co.'s. principle has, we believe, 

 been already made trial of on hothouse 

 roofs. Cast-iron, which is less liable to 

 corrosion than malleable iron, was dis- 

 carded on account of its liability to break, 

 unless used of a large size : this defect, 

 also, has very recently been mitigated. 

 Experiments made at the Crane Foundry 

 on the relative strength of cast-iron, chilled 

 and unchilled, showed that the process of 

 chilling gave a very great increase of 

 strength. The experiment shows a much 



