These are best hung with a pair of light, loose-pin bronze metal, or Stanley bronze-plated or japanned butts. They may be secured with a common latch or bolt, or by a double extension bolt. For windows not more than 3 feet high and opening in, a simple casement latch or turnbuckle, like that shown in Fig. 432, will generally prove satisfactory, as the strike is so arranged as to force the sash tightly against the rebate, and so short a sash is not likely to spring very much.

When the sash is over 4 feet high, however, a double extension bolt or an espagniolette bolt should be used, as if the sash is secured only in the centre it will be likely to spring badly at the top and bottom.

The mortise double extension bolt, shown in Fig. 433, makes a very neat finish and a very strong fastening. The Cremome bolt, shown in Fig. 400, page 374, is really a rim double-extension bolt, operated on the same principle, it makes a very handsome trimming for casement windows opening in or out. Casement windows may also be fitted with a mortise lock and latch with lever handle, special narrow locks being made for the purpose.

244. Double Casement Windows, or French windows usually have the meeting stiles rebated, so that when the swing leaf is secured it will also secure the standing leaf. The best fastening for a French window is believed to be either the mortise double-extension bolt or the espagniolette bolt or bar. The latter is much used in France, and possesses an advantage over the extension bolt, in that it is arranged so as to draw the sash firmly against the window frame, thus making more secure against the weather. Fig. 434 shows a double-rim espagniolette bar, made by the Yale & Towne Manufacturing Co., which not only secures the

Fig. 433.Double Extention Bolt.

Fig. 433.Double Extention Bolt.

Fig.434 -Double Rim Espagsashes but locks them together and draws them closely to their place. The operation of the bar is as follows: By turning the T-handle, the hasp is released from the locking plate, P, on the standing leaf, and by turning the handle back the bar is revolved and the hook is released from the strike at the top and bottom of the door.

243 Single Casement Windows 200320

A mortise espagniolette bar, working on the same principle is made by the Russell & Erwin Mfg. Co., and by P. & F. Corbin. If it is desired to secure the standing leaf independently of the other, a flush bolt maybe used at the top and bottom, but as it is usually desirable to open both leaves of a French window when operated at all, it is more convenient to use a single double-extension bolt or espagniolette bar.

Fie. 436. - Sash Adjusters..