A coal-bucket whose body can be set out on the assumption that it is part of an oblique elliptical cone is shown in the elevation (Fig. 173).

Overhanging Coal Bucket 187

Fig. 172.

The back and front are produced to meet in T, and a perpendicular, T t, run up to meet the line 0 6. Using t as centre, the points on the semi-ellipse are swung down on to the line 0 6, and the lines T 1', T 1", T 2', T 2", etc., drawn as in Fig. 170. The pattern is then set out as before explained.