The illustrated architectural, engineering, & mechanical drawing-book : for the use of schools, students, and artisans ; upwards of 300 illustrations (1856)
Burn, Robert Scott · London : Ward and Lock, 158 Fleet Street · leaf 130
fi.?. 33. tig. 32. Example 31, fig. 32, represents the Archimedean, or endless ^screw ;and another form is given in Example 32, tig. 33, where a h is the central shaft round which thehelix or thread e e is coiled, according to a determined pitch. Example 33, fig. 34, shows the method of drawing-in… … The circle, of which part is shown, and of which ch \% the radius, is termedthe pitch-cucle or line. It is on this line that the number of teeth aremarked oif. Having ascertained the diameter of pitch-line, the depth ofteeth, and the number of them, divide the pitch-circle into as many equalparts…
Architectural drawing · Mechanical drawing
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