Free-hand Perspective: For Use in Manual-training Schools and Colleges

angle of 30 angle of 45 applied approximately assumed auxiliary plane axes base cast shadow circle circular plane circumscribing cone conical surface construction convenient cube curve cutting plane descriptive geometry diagonal diameter directed plane distance drawing drawn effect elements ellipse equally inclined estimated foreshortening geometrical given plane greatest declivity hence hexagonal hori horizontal plane horizontal trace hyperbola initial trace invisible plane invisible shadow Large 12mo length light-rays line of direction line of intersection line of shade linear perspective located major axis measurements method move object oblique observer parallel pass a plane perpendicular perspective principles picture picture-plane plane of shadow plane passed plane perpendicular plane surface position prism rays of light receding edges required plane rotation seen shown in Fig square plane square pyramid standing station-point straight line tangent plane tion transparent plane triangle vanishing vanishing-trace vertical plane visible shadow zontal