544 



DETAILS OF CONSTRUCTION. 



claim on our part little attention either 

 for novelty or advantage. The means, 

 however, for removing the glass, either for 

 washing it, or for admitting the sash-bars 

 to be painted, as well as for rendering a 

 glass house so constructed a movable and 

 not a fixed structure, and thereby ena- 

 bling tenants or others to remove such 

 houses, are not without their advantages, 

 as well as the doing away with rebated 

 astragals, and fixing in the glass with 

 putty — two principles in hothouse build- 

 ing which should be avoided as much as 

 possible. 



Removing glass without breakage. — In re- 

 paring glass it is often found difficult to 

 remove the old putty, particularly if it 

 has been of long standing, and com- 

 pounded with white or red lead in its 

 formation. A little nitric or muriatic acid, 

 or a little strong vinegar spread over it, 

 will soften it so that it will remove easily. 

 The same means will remove paint. Rub 

 the putty with soft soap, and in a few 

 hours it will be sufficiently soft to part 

 with the astragals and glass freely. When 

 whole sashes are to be re-glazed, the putty 

 may be softened so as to admit of the 

 glass being taken out without breakage, 

 by placing the sashes over a pit filled with 

 stable dung in a high state of fermentation. 



Putty. — Much of the success of glazing 

 depends on the quality of the putty used, 

 and this depends on the materials used, 

 and the mode of manufacture. New putty 

 should never be used, as the older it is 

 the better. Indeed, putty-making has now 

 become a considerable trade of itself, and 

 steam-power is employed in preparing it. 

 Whoever, therefore, wishes to procure a 

 good article, should purchase it direct 

 from the manufacturer, as, if kept in close 

 barrels, it will keep for years, and only 

 requires to be beat up with a little linseed 

 oil as it is required for use. Glaziers em- 

 ploy four kinds, which may be considered 

 as being of relative strengths. 



Soft putty is well-wrought paste of flour 

 of whitening and raw linseed oil. This is 

 the worst kind, and is that often procured 

 from village glaziers. A better kind is 

 common whitening powdered very fine, 

 and thoroughly dried, and mixed with lin- 

 seed oil till of the consistency of dough. 



Hard putty, composed of whitening and 

 boiled linseed oil. 



Harder putty is that in which a portion 



Fig. 768. 



of turpentine, or what is called drying oil, 

 is introduced. These are the usual kinds, 

 and should be well dried before painting. 



Hardest putty. — This is used chiefly for 

 metallic roofs, or where the rebates are 

 small. The body of putty, therefore, being 

 small, it requires to be stronger in pro- 

 portion. This is composed of oil, red or 

 white lead, and sand. Another kind of 

 hard putty is often used for metallic roofs, 

 viz., mix as much red lead with good old 

 common putty as will make the whole of 

 a salmon colour. It is necessary to paint 

 the astragals with red lead mixed with 

 boiled linseed oil before glazing. It may 

 be painted any colour afterwards, but we 

 prefer stone to all other colours. 



Various means have been devised for 

 collecting »the condensed steam as well as 

 the rain water that finds its way through 

 hothouse roofs, one of which will be un- 

 derstood by fig. 768, 

 the invention of Mr 

 Neeves. It consists 

 in attaching small 

 copper gutters to the 

 astragals. These gut- 

 ters are fastened to the 

 bars with copper nails, 

 and extend the whole 

 length of the sash, de- 

 livering the water into 

 the gutter usually fixed 

 to the front of the 

 house outside. Mr 

 Rogers has recommend- 

 ed his own practice of 

 attaching small pieces of cobblers' wax to 

 the apex or sides of his astragals, to inter- 

 cept the streams of condensed steam, and 

 to cause it to fall into pots or baskets in 

 which plants are growing, and suspended 

 from the roof, that 

 l ' lg require this species of 



watering. 



The annexed fig., 

 769, shows a sash-bar, 

 full size, used by Sir 

 Joseph Paxton to pre- 

 vent the drip in one of 

 his orchid-houses. The 

 late Mr White of Had- 

 dington used metallic 

 gutters for collecting 

 condensed evapora- 

 tion, as will be seen 

 noticed in article Vineries, &c. Mr Saul 



