Upper and Lower Sash. Double-hung sashes are divided into two parts, one called the "upper sash" and the other the "lower sash," which are so arranged as to slide by each other. They meet at the center of the window opening, and at this point, at the top of the lower sash and at the bottom of the upper sash, is a rail known as the "meeting rail." In Fig. 316 is shown a section through the meeting rails of a window. The section has been taken vertically and shows the meeting rails at a large scale. A is the top rail of the lower sash and slides up. B is the bottom rail of the upper sash and slides down, the two coming together in the inclined line marked C. Each rail is cut so that when they come together they will meet in this line. The thickness of the rails is determined by the fact that the distance marked D is I inch, making the entire thickness of the rail B I -a inches and the thickness of the rail A 1 inches. The rail A is carried down below the bottom of the rail B so as to allow the glass to be puttied in as shown at E. In Fig. 317 is shown another method of fit ting the glass into the top rail of the lower sash. Here A is the top rail of the lower sash and at E is shown the method of fitting the glass. As will be seen, the rail is ploughed to a depth of about I inch and the glass inserted in the opening. This method allows the rail of the lower sash as well as the rail of the upper sash to be only 18 inches thick. Fig. 317 also shows another method of constructing the meeting rails as shown at C. Here, instead of meeting in a straight line as in Fig. 316, there is a slight rabbet made in each rail so as to give a small extent of horizontal surface on each. The advantage of this method is that it prevents the sashes from slipping too far past each other, as they may do if cut as shown in Fig. 316, especially after they have become a little worn.
At the corners, where the horizontal rails meet the vertical stiles, they are fastened together with a tenon joint, the mortise being in all cases cut in the stiles and the tenon made on the ends of the rails. This is shown in Fig. 31S where at A is the joint between the top rail and the stile, and at B the joint between the meeting rail and the stile. D is the top rail and E is the stile, while at H is the tenon cut in the end of D, fitting into a mortise in E. F is the meeting rail tenoned into the stile. It is a common practice to continue the stile some distance below the meeting rail and to cut a molding in the end of it as shown at C. This makes the stile much stronger at this otherwise weak point. The joint between the bottom rail and the stile is made in a manner similar to that shown at A.
Mantins. When there are more than two lights in a window opening, the sashes must be subdivided and the panes of glass made smaller, and this subdivision is accomplished by means of pieces called "muntins" which are made so as to receive the glass in the same way as do the rails and stiles. In Fig. 319 is shown a window sash divided into lights, four in each sash, and at is shown a muntin. In Fig. 320 is shown a full-size section through one of these muntins showing the way in which it holds the glass. A is the body of the muntin, BB is the glass on the two sides of it, held in place by the putty CC. The molding DD may be varied to suit the taste of the designer, but must be the same as on the rails and stiles.
Casement Sash and Frames. The frames and the sash before described, known as "double-hung sash" or "English sash with box frames," are those most commonly employed in the United States and Canada, but there is another kind of sash known as "case ment or French" sash which is con structed on a different principle entirely.
This sash is hinged at the sides to the frame so as to swing either in or out. The principal objection to this arrangement is the difficulty of making such a sash water- and weather-tight. It is also impossi ble to use outside fly screens, if the sashes are hung to swing out, and if they arc hung to swing in, the weather can penetrate through them much more readily. In Fig. 321 is shown a horizontal section through the side or jamb of a casement window in a frame wall. It will be seen that the outside architrave is sitMlar to the one which was described in connection with the double-hung window, and in this respect there is no difference between the two. There is, how ever, no box for the accommodation of weights in this case, as no weights are required. The outside architrave is made in a way slightly different from any which have been illustrated before, but this method is equally well adapted for use with the other type of window. As shown at II it is made in two pieces, H being per fectly plain and the molded piece K worked out of smaller stuff and fastened on to it. It will be noted that the piece K is rabbeted slightly and that the end of the piece II fits into the rabbet in such a way that the joint between the two pieces is hidden from the front, and may open a little without being noticed.
In the figure, AA are the studs at the sides of the opening, I is the outside boarding and J is the plastering on the inside. B is the frame for the easement window, which in this case is made very thick, 21 to 24 inches in thickness, rabbeted inch, as shown at E, to receive the sash C. The sash itself is rabbeted and a groove is cut vertically in it, as shown, in order that any rain waterwhich may pene trate the joint at E may be stopped and may run down the groove to the sill without getting inside. D is the stop bead and G is a block which receives the inside architrave F. The sash is hinged at the point E and swings out. In Fig. 322 is shown another method of constructing a casement window so that the sash will swing out ward. In this case the sash is placed much nearer the outside of the frame and the frame is made much lighter than in the design shown above. The frame B is made from stuff only 14 inches thick and is made wide enough to extend in to the plaster line, thus doing away with the block G in Fig. 321. The stop bead D is also omitted. The frame B is rabbeted near the outside edge to a depth of about 4 inch to receive the sash C and an extra groove is cut in the frame to receive a half-round molding cut in the edge of the sash. This arrangement is to keep out the weather. The sash C is 14 inches thick and n inches wide. There are, of course, many other ways of constructing these frames and sashes which are more or less elabo rate, according as the work is intended to be cheap or good. The designs shown are suitable for ordinary, good work and may be sim plified for cheap work.