A textbook on mechanical and electrical engineering (1902)
International Correspondence Schools · Scranton : International Textbook Co. · leaf 436
e edge line at x, and itscorrect distance from the vertex O bethere ascertained. The point x, there-fore, could be projected to either ele-ment O A or OB, but the supposed rev-olution is generally represented as beingmade towards the true edge line that isnearest the point whose location it is… … Fig. s}7 4-2 DEVELOPMENT OF SURFACES § 16 horizontal line x.r is drawn in the elevation, and the distancefrom the point O to-the point x is then the exact, or true,distance between the two points. The same result wouldbe obtained if an elevation were drawn showing the ele-ment O C in its true…
