Elementary mechanical drawing, for school and shop (1886)
Aborn, Frank, 1845- [from old catalog] · Cincinnati, New York, Van Antwerp, Bragg & co · leaf 43
Second Method.—To De-scribe an Ellipse with aString. , Note.—To describe an ellipsewith a string is frequently veryconvenient; but as a string iselastic, it is unreliable. Forthis reason, it should neverbe used in describing ellipses,except where only quick, ap-proximate results are required. Prob.… … 42 MECHANICAL DRAWING. string and tie a loop, the length of which, ab, isequal to AB. Set a pin in each focus, F and F,and drop the loop over them, xyz. Place the pencilagainst the loop, and push it out to C. Then movethe pencil either way, pressing against the string,and describe one half of the…
Mechanical drawing
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
