In Fig. 152 make a drawing, from d to h, of the cross-section of the hand-rail, and tangent to the lower corner draw the line gh The distance between the lines je and g h is the thickness of the plank from which the rail is to be cut. Lay the face-mould upon the plank, mark its shape upon the plank, and saw it square through. To proceed . strictly in accordance with the requirements of the principles upon which the lace-mould is formed, the cutting ought to be made vertically through the plank, the latter being in the position which it would occupy when upon the stairs. Formerly it was the custom to cut it thus, with its long raking lines. But, owing to the great labor and inconvenience of this method, efforts were made to secure an easier process. By investigation it was found that it was possible, without change in the face-mould, to cut the plank square through and still obtain, the correct figure for the railing, and this method is the one now usually pursued. Not only is the labor of sawing much reduced by this change; but to the workman it ,s a entire relief, as he now, after marking the form of the wreath upon the plank, sends it to a steam saw-mill, and, at a small cost, has it cut out with an upright scroll-saw. When thus cut out in the square, the upper surface of the plank is to be faced up true and unwinding, and the outer edge jointed straight and square from the face. Then a figure of the cross-section of the hand-railing is to be carefully drawn on the ends of the squared block as shown in Figs. 154 and 155, and which are regulated so as to be correctly in position, as follows. First, as to the end h of the straight part hj; In Fig. 154, let ab c d be an end view of the squared block, of which a efd is the shape of the end of the straight part. Let the point g be the centre of this end of the straight part; through g draw upon the end a efd the line j k, so that the angle bjk shall be equal to the angle kt c, Fig. 152. This is the angle at which the plank is required to be canted, revolving it on the axis of the straight part of the rail. Through g draw the line n h parallel with a b. Upon a thin sheet of metal (zinc is preferable) mark carefully the exact figure of the cross-section of the rail, drawing a vertical line through its centre, cut away the surplus metal, then, with this template as a pattern, mark upon the end a efd, Fig. 154, the figure of the rail as shown, the vertical line upon the template being made to coincide with the line j k. From n and h draw the vertical lines h m and l n parallel with jk.
Now, as to the other end of the square block: Let b efe,
Fig. 155, represent the block, of which bcvn is the form of the end at the curved part, and 0 its centre. Through 0 draw, pq so that the angle epq shall be equal to the angle j n b, Fig. 152. Also, through o draw d h parallel with e b;
from d and h draw the vertical lines h r and ds parallel with pq. Place the template on bcvn, the end of the block, so that the vertical line through its centre shall coincide with pq; mark its form, then from y, at mid-thickness, draw wy parallel with p q.
In applying the mould, let Fig. 156 represent the upper face of the squared block, with the face-mould lying upon it. With the distance a l, Fig. 154, and by the edge a x, mark a gauge-line upon the upper face of the squared block. Set the outer edge of the face-mould to coincide with this gauge-line. Let the end of the face-mould be set at w, e w being equal to e w, Fig. 155; then mark the block by the edge of the face-mould.
Now turn the block over and apply the face-mould to the underside, as in Fig. 157. With the distance d w, Fig. 154, and by the outer edge of the block, mark a gauge-line from m, Fig. 157. Set the inner edge of the face-mould to this gauge-line, and slide it endwise till the distance em shall equal ew, Fig. 155, then mark the block by the edges of the face-mould. The over wood may now be removed as indicated by the vertical lines at the sides of the cross-section marked on each end of the block (see also Fig. 167): the direction of the cutting at the curves must be vertical; the inner curve will require a round-faced plane. A comparison of the several figures referred to, with the directions given, together with a little reflection, will manifest the reasons for the method here given for applying the face-mould. Especially so when it is remembered that the face-mould was obtained not for the top of the rail, but for the rail at the mid-thickness of the block. So, therefore, in the application to the upper surface of the block, the face-mould is slid up the rake far enough to put the mould in position vertically over its true position at mid-thickness; and on the contrary, in applying the face-mould to the underside of the plank, it is slid down until it is vertically beneath its true position at the mid-thickness of the block.
When the vertical faces are completed, the over wood above and below the wreath is to be removed. In doing this, the form at the ends, as given by the template, is a sufficient guide there. Between these the upper and under surfaces are to be warped from one end to the other, so as to form a graceful' curve. With a little practice an intelligent mechanic will be able to work these surfaces with facility. The form of cross-section produced by this operation is that of a parallelogram, tangent to the top, bottom, and two sides of the rail; and which at and near the ends of the block is not quite full. The next operation is that of working the moulding at the sides and on top, first by rebates at the sides, then chamfering, and finally moulding the curves. Templates to fit the rail, one at the sides, another on top, are useful as checks against cutting away too much of the wood.
The joints are all to be worked square through the plank in the line drawn perpendicular to the tangent, as shown in Fig 153.