The carpenter and joiner's assistant : being a comprehensive treatise on the selection, preparation, and strength of materials, and the mechanical principles of framing, with their application in carpentry, joinery, and hand-railing : also, a course of instruction in practical geometry, geometrical lines, drawing, projection, and perspective : and an illustrated glossary of terms used in architecture and building (1860)
Newlands, James, 1813-1871 · Glasgow : Blackie and Son · leaf 437
traight line, to find the length and direction of the sliadoiv of the line on the horizontal plane. Let a b (Fig. 529) be the common section of the two planes, c the luminous point, c d its projections, and d, d' d' those of the straight line. Then draw the line C D representing the ray from c,… … Let / F (Fig. 530) be the given line. Through it, and point will be the shadow of the point D. Other rays through the light C, suppose to pass a vertical plane, of Cl, c 2, will be intercepted by D d, and there will be which the horizontal trace is d g , then draw the ray CF behind d D, therefore,…
