Practical engineering drawing and third angle projection, for students in scientific, technical and manual training schools and for ... draughtsmen .. (1897)
Willson, Frederick Newton, 1855-1939 · Princeton, N.J., The author · leaf 167
lane of projection, usually called the datum or reference plane, is taken, ordinarily, belowall the points that are to be projected, although when mapping the bed of a stream or other bodyof water it is generally taken at the water line, in which case the numbers, called indices or refer-ences,… … In Fig. 403 the curves indicate such a series of sections made by planes one yard, metre orother unit apart, the larger curve being assumed to lie in the reference or datum plane, and there-fore having the index zero. The profile of a section made by any vertical plane JfiV would be found by laying…
Mechanical drawing · Lettering
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
