Worthen, William Ezra, 1819-1897, [from old catalog] ed · New York, Appleton · leaf 128
Fig. 242. Fio. 243. larger circle; through the centre of this smaller circle draw a diameter E F, anddivide the arcs E 0 and 0 F into nine equal parts; and from the pole D,through each of these points, draw lines intersecting the equator. These linesdivide the equator into eighteen parts, each…
Mechanical drawing
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