Practical plane and solid geometry for advanced students, including graphic statics, adapted to the requirements of the South Kensington syllabus (1899)
Harrison, Joseph, Baxandall, George Albert · London Macmillan · leaf 438
und is obtained by consideringrays which pass through the points on the line of separa-tion. For example, the points P give the shadows />„, p0. One half of the surface is illuminated. Examples.—1. Determine the shadow cast on the horizontalplane by the surface of revolution in Ex. 1, Prob. 282,… … Draw a line ab parallel to xy, 1 J above it and 2^ long. Witha/ as radius, and a and b in turn as centres, describe arcscommencing at b and a and terminating in xy. This is theelevation of a surface of revolution ; determine the shadow caston the ground, the rays being parallel to the vertical…
