124 



HOTHOUSE-BUILDING. 



fig. 126 is a section as an example, will 

 be 5 feet 10 inches long, and 3 feet 2| 



Fig. 126. 



inches in breadth, excepting the upper- 

 most range on each side of the ridge, 

 which should only be 19 inches in breadth, 

 as they are to be made to open for top 

 ventilation, as shown in fig. 126, a a, 

 where they move on an axle extending 

 the whole length of the house, to which 

 they are attached at their centres ; they 

 are shown open. The top and bottom rails 

 are to be 2 inches by 3, and half-checked, so 

 as to lap over each other 1^ inch, to carry 

 over the rain water ; and the side rails or 

 styles are to be 2 inches square, and to 

 rest 1 inch on the rebate of the rafters 

 on each side ; — thus reducing the opaque 

 space of the rafter and styles to 3 inches, 

 and that of the top and bottom rails to 

 the same breadth. Each sash is to be 

 furnished with four brass pivots attached 

 to the top and bottom rails, 6 inches from 

 each corner, and f of an inch in diameter, 

 as shown in fig. 125. These pivots are 

 to repose in brass sockets sunk in the 

 rafter, and to be kept in their places by 



Fig. 127. 



brass clasps over them, as shown upon a 

 large scale in fig. 127, which is a portion 

 of the rafter. These clasps are screwed 

 down at each end. The astragals are to 

 be also of wood ; and, on account of their 

 being so short, they will cut out of board- 

 ing without much waste, as the radius is 

 so small. From this it will readily be 



seen that, when the roof has to be re- 

 moved either wholly or in part, all that 

 is required is to unscrew the brass clasps, 

 and to lift the sashes out; and these, 

 being only 6 feet by 3, may be removed 

 with the greatest safety. If rough plate 

 glass is used, then one piece, bent to the 

 required curve, may be employed to fill 

 in each of these sashes, and if of the thick- 

 ness of I of an inch, this will be stronger 

 and less liable to breakage than if smaller 

 panes and astragals were employed. 



We consider the removal of the roof 

 sashes much more practicable, and ad- 

 mitting of greater advantages than that 

 of adopting the poly-prosopic principle, 

 which requires complicated machinery 

 to move, besides placing the sashes in a 

 position of great danger from winds while 

 they are set open. Another advantage 

 attending the entire removal of the sashes 

 is, that, during the time they are not in 

 use, they can be thoroughly painted, 

 glazed, or repaired. 



One objection to curvilinear houses, 

 and we think a very serious one, is the 

 difficulty hitherto experienced in procur- 

 ing sufficient ventilation for them. This, 

 to a certain extent, is chargeable on all 

 fixed roofs j and we have been, in general, 

 too sparing in providing openings suffi- 

 cient to effect this purpose. 



In the case before us, we would divide 

 the parapet walls on both sides, and at 

 the ends also, into as many spaces as pos- 

 sible, leaving only 3-feet piers between 

 each ; and as the walls are to be 3 feet in 

 height, each ventilator (a a) on fig. 128 



Fig. 128. 



maybe 18 inches in height: their lengths 

 will be found by dividing the length of 

 the house into equal parts. The top 

 ventilation is secured by openings in the 

 roof near its apex, as shown in fig. 126. 



