GENERAL PRINCIPLES. 



123 



The rafters are 12 inches deep, 1^ 

 inch in the narrowest part, 5± inches 

 through the rebates, and 3^ inches at 

 the crown, vide fig. 124. 



Fig. 124. 



«-~--3*i- > 



The house is glazed with sheet glass, 

 21 ounces to the square foot, in panes 3 

 feet 2 inches by 9^ inches. A green 

 tinge is given to the glass by means of 

 oxide of copper, with a view to counter- 

 act the effects of white sheet glass on the 

 plants below — a plan suggested by Mr 

 Hunt of the Museum of Economic Geo- 

 logy, and exemplified by him in this 

 house for the first time. Our figs., with 

 slight alterations, are taken from " The 

 Builder." 



A great mistake has been fallen into in 

 the construction of the general smoke 

 flue, by not having it placed within a 

 chamber surrounded by air, so as to pre- 

 vent the abstraction of its heat, and the 

 exclusion of damp, to which it is at pre- 

 sent so subject as to render it scarcely 

 possible to make the smoke pass through 

 it, notwithstanding its length and great 

 height of chimney. 



Curvilinear houses.— In regard to cur- 

 vilinear roofed houses, none, we think, 

 will deny them the merit of elegance in 

 appearance, and of capability of admit- 

 ting abundance of light ; but many object 

 to them on the ground of insufficient 

 ventilation, and of the impossibility of 

 removing them, either in whole or in 

 part, at certain seasons of the year ; this 

 latter objection being common to them 

 with all houses having fixed roofs. We 

 see little difficulty in overcoming these 

 objections, as a reference to various 

 methods of ventilation will show • and we 

 have a model before us of a curvilinear 



house so constructed, intended for peach 

 houses and vineries, which will form the 

 subject of our next plate, and in which 

 we shall show that the whole of the glass 

 roof may be removed with almost as little 

 trouble as that of a lean-to house of the 

 ordinary description. We are not aware 

 that any plan has hitherto been adopted 

 to effect this end, of removal of the 

 roof in the case of such houses — an end 

 which, if carried into effect, would mate- 

 rially lessen the objections with which 

 such roofs have been very justly charged. 

 We all know the great advantage which 

 peaches and vines, in moderate climates, 

 enjoy in houses where they can be freely 

 exposed to the action of the weather, from 

 the period of their buds and wood being 

 fully matured, till they are again to be ex- 

 cited into growth ; and that exposure is more 

 necessary in the case of trees early forced, 

 than in those the ripening of whose fruit is 

 kept back to a later period of the season. 

 This has hitherto been with us, as well as 

 with most cultivators, a prominent objec- 

 tion to curvilinear houses, because their 

 roofs are fixed, and all the ventilation in 

 general given to them cannot entirely re- 

 medy this defect. We propose, therefore, 

 that the rafters of these houses should be 

 constructed of deck-beam metallic bars, 3 

 inches thick and 4 inches deep — that they 

 be fixed in a massive stone coping on the 

 parapet walls, and joined together at the 

 top, and 6 feet apart centre from centre, 

 with a rebate on each side 1 inch in 

 breadth, and 2 inches deep, for the recep- 

 tion of the sashes, and kept in their pro- 

 per place by straining bars, of which one 

 on each side of the roof of smaller houses, 

 and two on each side of larger ones, will 

 be sufficient, with one along the apex or 

 ridge, to tie them all together. The 

 rafters are to be provided with a wooden 

 coping, projecting 1 inch on each side 

 over the side styles of the sashes. The 



Fig. 125. 



sashes, fig. 125, are to be of well-seasoned 

 timber, and, taking the house of which 



