draw in the inside edges parallel. Draw diagonal lines joining the opposite eight angles, and on each side of these draw in half the thickness of the hips. The octagonal finial is 7 in. in diameter. The purlins are drawn parallel with the curl) sides, and at such a distance from the finial that the greatest distance between the hips above the purlin will not exceed one foot, otherwise excessively thick boarding will be necessary for covering. The covering boards in this case will run horizontally. At the middle of each bay draw in an intermediate rib, as shown in Fig. 2.

The elevation, Fig. 1, is also shown as a section of the roof on the line A-B, which is usually placed parallel with the principal front of the building.

Before completing the section we will consider the method of deducing the shape of the hip or angle rib from the given section, as shown on the right-hand halves of Figs. 1 and 2.

To obtain Mould for Shape of Hips.—Draw the approved outline of roof by describing curves of conlrary flexure as shown ; the given radius is 5 ft. 3| iti and the centres are upon levels taken at the top of curve and top of ribs—in other words, at the springings. Take any number of points in the curve, as 1, 2, 3, 4, 5, 6, and drop projectors from them into the plan, cutting either of the hips (centre line) in points 1', 2', 3', 4', 5', 6'. Upon these points erect perpendiculars to the plan of the hip, and make them equal in height to the same numbered ordinates in Fig. 1. measuring the latter from the top side of curb. Having obtained the points, I*, 2", 3", 4", 5", 6", draw the curve through them. This mould will give the shape to cut the hips out to, also the line of "backing," if moved inward horizontally on the curb, until its edge coincides with the side of the hip as shown in the plan. This will be better understood by referring to the elevation, where the hip just in front of A is shown in elevation, with the backing of one side, the other side being, of course, invisible.

To draw the Elevation.—.Having produced the outline as described previously, divide it into a number of parts as

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Freehand Sketching An Introduction

Freehand Sketching An Introduction

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