A textbook on mechanical and electrical engineering (1902)
International Correspondence Schools · Scranton : International Textbook Co. · leaf 389
Fig. 1 {b). Assume now that the prism is laid on thedrawing board, the surface A face down, and the papercovering removed by turning the prism over and over, thepaper remaining on the surface of the drawing board, asshown in Fig. 2 {a) and {b). Two important principles relating to developments… … Fig. 2 from Fig. 2 {b), the edges a b, c d, e f, g h, and a /^are allparallel to one another. This is true both in the develop-ment and on the solid, as may be readily seen by thestudent, the only difference being that on the solid certainof the lines are in different planes, while in the…
