Hasluck, Paul N. (Paul Nooncree), 1854-1931 · London ; New York : Cassell and Co. · leaf 90
lf pitch apart, through 4, 1, J, and K, as the same curve will be found to repeat itself in each of these divisions. As twelve divisions have been made on the semicircle, so twelve divisions must be made between D and u, and horizontal lines drawn through as shown. This will give a series of inter-… … 0 oe eee Oe eee beet boa -4--4----- ' Dy Ve -4--7----- Cent af oe ee ’ 4 Fig. 147.—Projection of a Helix. can be most readily drawn by using the half pitch lines J, J, and K, and with the compasses or bow pencil marking off upon the verticals all the places where the curve is one division up cr…
Mechanical drawing
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