52 Notes and Gleanings. 



sufficient for all ordinary houses. Another point is the absence of rebates. The top 

 of the bar is quite level and smooth. Along its centre, at intervals of thirty inches, 

 small screw-holes are formed. Into these a small bolt is screwed about three-quarter- 

 inch deep. I shows the bar with the bolt (3) inserted ; 2 is a three-quarter covering bar ; 

 and 4 a small cap-nut, made of hard white metal which cannot corrode. These parts 

 complete the metallic portion of the bar. 



The most important part has now to be noticed. On each side of the glass, a dark 

 space, marked 5, will be observed. This is a strip of asphalted felt of the best quality. 

 It forms an elastic bedding for the glass, and separates it at all points from contact with 

 the iron. This is of great importance. Iron is not only an active conductor of heat, but 

 is sensibly altered in bulk by sudden changes of temperature. It expands with heat, 

 and contracts with cold : hence, if it touched the glass at any point, it would probably 

 break it ; in fact, it does break it extensively on many metallic houses. The intervention 

 of the felt, and the small space left between the two squares of glass as they lie side by 

 side on the top of the bar, allow of sufficient elasticity in these houses to enable them to 

 endure all changes of temperature without breakage of glass. The felt and glass, meet- 

 ing on the top of the rafter, perform another almost equally important and useful func- 

 tion : they moderate extremes of temperature in these houses. Such metallic roof-bars 

 are probably about as cool and as warm as wooden ones. The felt and glass break the 

 currents of caloric passing through, and insulate the two portions of the bar from each 

 other. The strength and durability of the fixmg power will be obvious. It is composed 

 wholly of iron, or other metal : the felt is simply an elastic padding ; and protected as it 

 is at all points, except the thin edge, from the weather, it will probably last good for 

 twenty or thirty years. 



The glass used is large, — thirty inches by twenty, — and weighs about twenty-eight 

 ounces to the foot. On steep-pitched roofs, it can be laid on end-to-end without danger 

 of drip. At lower angles than 40°, it will be safer to overlap. The glazing is equally 

 simple on either method. When the glass is lapped, the covering bars are made the 

 same length as the squares. If it is unlapped, they may cover two or three. Whichever 

 mode is adopted, nothing can be simpler than the replacement of a square that may have 

 become broken by accident. Only two or three small nuts have to be unscrewed, a 

 length of bar lifted off, the glass laid on, the bar replaced, and the nuts screwed down 

 again ; the whole process occupying less time than the reading of these lines. 



The erection of these houses is equally simple and rapid. They might almost arrive 

 in a bundle and crate in the morning, and be furnished with growing plants before night. 

 Whilst the most durable houses that have yet been built, they are also the most portable. 

 This, and their completeness in themselves, render them valuable to tenants. They 

 could be moved as readily as a library or a cellar of wine, with less trouble and inter- 

 ruption to their legitimate functions. The enamelling is also another valuable character- 

 istic of these houses. Just as the felt supersedes putty, so does the enamel promise ut- 

 terly to abolish the worry, expense, and disagreeable smell of common paint. It is baked 

 on at a high temperature, a sort of flux being thus formed with the metal and the lead, 

 so that the one seems inseparable from the other ; and a smooth, hard surface is formed, 

 which will easily wash clean, and promises to endure for years. 



Having thus pointed out the most obvious structural merits of these houses, 

 and shown how they do away with the necessity for repairs, while combining 

 the rare merits of strength, durability, cheapness, elegance, and portability, 

 their high cultural efificiency will hereafter be alluded to. 



A FEW Hints on the Culture of the Balsam. — After having obtained 

 the seed of some variety which has been very highly recommended, and seeing 

 in perspective its beauties developed in summer, nothing is more annoying to 

 the grower of this beautiful plant, than to find, after having grown the plants for 

 a month or two, that they must be put out of sight to hide their lanky stems. 



Having procured seed of the camellia-flowered varieties (if a year or two old, 

 so much the better), sow towards the end of March, in light sandy soil, about ten 

 or twelve seeds to a 48-sized pot. Place the pot in a cucumber or melon bed at 



