These are almost invariably made of planks, and are usually fitted with a single sash from 16 inches to 2 feet in height and from 30 inches to 3 feet wide, hinged at the top to open in.

Fig. 91.

Fig. 99.

Fig. 91 shows sections through the sill and head of a cellar window of a frame house, as ordinarily constructed, although in the very cheapest work the jambs and heads are sometimes made without rebates, a strip called a "stop" being nailed to the frame for the sash to strike against. A moulding, S, is generally nailed to the outside edge of the frame to make a closer joint between the frame and the mason work. This moulding may be of various shapes, but a better joint is made by having a quirk on the outer edge. In all frames built into stone or brickwork this moulding is called the "staff-bead," or, in some localities, the "brick mould." The head and sill should project beyond the sides or " jambs," so as to form lugs for securing the frame to the wall, and the jambs should be let into them ½ inch.

• The term *' ceiling " as used in this book refers to matched and beaded boards ; in Boston, and possibly elsewhere, the term "sheathing" is used to denote the same thing.

The frame shown in Fig. 92 shows a better construction in one or two respects. The most important of these is the shape of the sill, which makes a tighter joint than that shown in Fig. 91. This frame is also provided with vertical iron bars, placed about 4 inches apart, as a security from burglars, and the fly screen is put in from the inside. The sides of the frame have the same section as the head.

The detail at A shows a section sometimes used for the jambs and head of cellar frames. Where the jamb is in one piece, however, it is apt to warp away from the masonry, and, in the opinion of the author, is not as good construction as where a separate staff-bead is used. It is a good idea with all plank frames to nail 2x2-inch strips to the back of the jambs, as shown at A, for holding the frame securely in the wall.