Mechanical drawing. Elementary and advanced (1910)
Reid, John S. (John Simpson), 1856- · New York, J. Wiley & sons; [etc, etc.] · leaf 135
the visible line of deepestshade on the cylindrical column. The deepest line of shade 1, 2 on the abacus is found inthe same way. The line of shadow on the column of that portion of thelower circumference of the abacus which is toward the sourceof light is found by passing vertical planes of rays,… … Take the cone as given in Fig. 164. Pass two planes ofrays tangent to the cone; their elements of contact will bethe deepest lines of shade. To determine the elements ofcontact draw a ray through Cv\ CXH i»s its hor. trace. From ORTHOGRAPHIC PROJECTION. 121 C draw lines tangent to the base at D and…
