50. At {d) is shown a section through the window head at the center of the opening. Here the stud a' is shown in its position at the top of the frame opening, while the window head g' is shown 2 inches below; these 2 inches permit projections of the stiles, shown in (e) at v w, to be fitted to the top of the opening. The inside trim j" is then secured across the opening between the casing g' and the stud a', and the outside trim c' is laid over the exterior casing b' and extends to the sheathing at the edge of the framed opening at o'. A cap member should be placed over the upper edge of the casing to shed the water, or a cap flashing of copper or lead may be used.

Windows Continued 367

Fig. 24.

Windows Continued 368

Fig. 25.

This practically completes the description of the details of the frame for any single window in a frame building such as shown in Fig. 24; when, however, windows are coupled in pairs or triplets, a dividing member, called a mullion, must be included in the frame, as shown at a in Fig. 25.

51. A mullion is simply a division placed between two sashes. With sliding sashes it must contain the weight box for their inner edges, but with hinged sashes it need be no more than a bar, against which the sashes may close, and upon which they may be hinged. The former kind is illustrated in Fig. 26, which shows a horizontal section through the mullion a in Fig. 25.

Inasmuch as the mullion may contain four weights (two for each pair of sashes), instead of two weights as in the box of a single window, the inside trim a and the outside trim c must be somewhat wider than the same details are in a single frame.

The pulley stiles b, the stop-beads c, and the parting strips a are detailed in precisely the same manner as in a single frame, but the distance between the stiles b being from 4 to 5 inches, in order to accommodate the weights d, the casings require to be proportionately wider to cover the joints. The pocket in the pulley stile may exist on one side of the mullion only, as access to all four weights can thereby be readily attained. The sill of the window, however, is not gained into the pulley stile of the mullion, as is the case with the single frame shown in Fig. 23. Instead, the sill and the window head each extend as one piece across both openings, and each is grooved to receive the mullion pulley stiles.

52. When a window frame is required for insertion in the opening of a brick or stone wall, the details shown in Fig. 23 must be considerably altered in order to make the frame fulfil the requirements. Fig. 27 shows at (a) the interior elevation of such a window; at (b), a horizontal section; at (c), a vertical section; and at (d), a section through one of its pulley stiles. In the horizontal section (b) the weight boxes with the details of their construction are shown at f. The brick wall g is 12 inches thick, with a reveal at g' of 4 inches. At h is shown the outside lining, into a groove of which is tongued the pulley stile i, which in turn is, in a similar manner, let into the inside lining j. These three pieces form a box f, in which are hung the two sash weights k, separated by a wooden tongue /, to prevent them striking together when the sash is raised or lowered. The weight box is closed by the back lining m. The pulley stile i is grooved to receive the parting bead o, which, with the 1/2-inch or 5/8-inch projection of the outside lining h, secures the upper sash in its place and provides a way in which it may slide. The parting bead may be of hardwood from 1/2 in. X 1 in. to 5/8 in. X 1 1/4 in. section. The lower sash slides inside of the parting bead and is secured in place by means of the stop-bead p.

Windows Continued 369

Fig. 26.

Windows Continued 370

Fig. 27.

In the angle between the outside lining h and the brick reveal g', is placed a casing q to which outside blinds or shutters may be hung, though sometimes it is of some special design. The jamb lining d is secured to the inside lining j, and extends to the floor; the architrave, or trim c, is attached to it, and by covering the ground, binds the plaster joint at r.

The top of the window frame is shown in Fig. 27 (c). Here the exterior casing or angle mold is mitered in the corner and is carried across the top of the window as shown at q', while the outside lining is butted in the corner and carried across the top of the opening, as shown at h'. The window head i' is let into the pulley stiles and plowed to receive the parting strip o'. The stop-bead p' is mitered in the angle and returned across the top of the frame, covering the joint between the window head i' and the inside casing d'. The pulleys m' are the same as in the former case, and the pocket, as shown at x' g', gives access to the weights.

The sill s' in this case rests its outer edge on the stone sill u' instead of on a wooden sub-sill, as in the previous example. There is also a break or step in the thickness of the sill where the stop-bead meets it. When set, the sill is laid on a bed of mortar spread over the stone sill u', and this mortar, being forced up into the groove shown at t', makes a perfectly water-tight joint between the two sills.

From the sill to the floor, on the inside of the window, the wall is covered by a panel back, or breast, as shown in the elevation (a) at w. The stiles, rails, and muntins of this panel back are grooved on their edges and mortised and tenoned together, as are also the same details in the doors. The lower rail is scribed to the floor, and the upper rail is capped by the wooden sill of the window, as shown in the section (c). A molding is then set into the angle between the sill of the window and the rail of the panel back, and finishes the joint. The stiles of the panel back are considerably wider than those shown at (a), as they extend beyond and behind the jamb lining.

53. Sashes vary slightly in their construction, according to the manner in which they are hung, and the character of the building for which they are intended. Sashes of ordinary dimensions are from 1 1/2 inches to 2 inches in thickness, with the bottom rail 3 1/2 inches to 4 inches in width, while the stiles and top rail are 2 inches in width. The meeting rails of double-hung sashes are usually 1 1/2 inches wide, and are beveled, as hereafter described, to insure a tight joint.

Sashes which are to be glazed with heavy plate glass should be at least 2 inches thick, and should have a bottom rail 4 or 5 inches wide.

The outside dimensions of window sashes are dependent very largely upon the regular market sizes of glass, it being economical to use glass in sizes that can be procured without cutting to waste.

A table of the sizes of window glass and the number of panes in a box is given herewith; a box being supposed to contain 50 square feet of glass.