Let A G L in Fig. 442 be the elevation of the spire, and MOP the half plan. From the point G, which represents the lowest point of the angle or valley between the gables, to H, which represents the meeting of the valleys and ridges at T in the plan, draw the line G H, cutting the side A C extended in the point D. Draw any line, as A1 D1 in Fig. 443, upon which to construct the pattern. Make A1 C1 equal to
A C of the elevation, and A1 D1 equal to A D of the elevation. Through D1 draw the horizontal line 1 0, as shown. From D1 set off D1 O, equal to E F of the elevation, and likewise set off D1 1, of the same length.
Fig. 442. - Plan and Elevation of Spire.
Fig. 443. - Pattern.
The Pattern of an Octagon Spire Mitering Upon Eight Gables.
Draw A1 0 and A1 1. Set the dividers to A1 1 as radius, and from A1 as center describe the are 1 8 indefinitely. Set the dividers to 1 0, and step off as many spaces on the arc as there are sides in the spire. Draw the lines A1 2, A1 3, etc., to A1 8, which represent the angles of the spire and the bends in the pattern. Draw C 0 and C1 1 in the first section of the pattern. Set the dividers to C1 1, and from 1 and 2 as centers describe intersecting ares, as shown by C2. In like manner describe similar intersecting arcs at the points
C3 , C4, etc. Draw lines from these points to the points 1, 2, 3, 4, etc., as shown, thus completing the pattern.