Pavilion Roof

allows it to swell and shrink without splitting (see also page 95 for details). Fig. 5 is a section of the return counter, and its use is to obtain heights for the elevation. Fig. 6 is an enlarged detail of the drawer blocks and runners. Fig. 7 is an enlarged detail through the door, etc.

Lay down the plan in outline first, according to the figured dimensions, then reproduce Fig. 4 unbroken to given dimensions. Work this with care, because all the parts in the smaller scale drawing will be taken from it. No particular order need be taken in making such a drawing, other than to observe the general rule to get in the outline first, then the main features, leaving small details until the last, so that in case of any error in the main dimensions less time will have to be lost when making corrections. Also remember that in technical drawing it is the important things that count, not feeble fidelity to truth ; for instance, to make my meaning clear, it is important to draw the handles of the drawers exactly where they are wanted, but it is not important to show their detail of moulding, or even their exact size ; in practice, the specification will sufficiently indicate this to the constructor. See also remarks on the same subject in Chapter IX., " Workshop Drawings," 4

The Octagonal Ogee Roof shown on page 72 is suitable for a turret or a pavilion roof. We will assume that the given data are, that the side of the octagon is to be 3 ft. 4 in. and the span 8 ft. 3 in.; height, 8 ft. from underside of curb to top of ribs; the curb, 6 in. x 4 in.; hips, 2 in.; ribs 1J in.; purlins, i| in.

Proceed to draw the plan. At any convenient place, draw 1 he line.l -B and set off on it the given span as at a-b; at these points draw lines perpendicular to A-B on each side. Make these lines equal to the length given for the side—3 ft. 4 in. as at X-X' ; then bisect a-b, and from the centre describe a circle passing through the points A'-A''. This circle will contain the ends of all the hips. Around its circumference set off eight divisions, equal in length the given side, and join up these points, which will give the outline of the curb ;

An Ogee Pavilion Roof Fig. I. Sectional Elevation. Fig. 2. Plan. Fig. 3. Joints at Finial Figs. 4. and 5. Joints at Foot of Ribs