Mechanical drawing. Elementary and advanced (1910)
Reid, John S. (John Simpson), 1856- · New York, J. Wiley & sons; [etc, etc.] · leaf 122
of light to be parallel and the pointof sight at an infinite distance, the brilliant point on the sur-face of a sphere is found as follows: Let AVCV and AhChy Fig. OR 7HOGRAPHIC PROJECTION. 107 145, be a ray of light and AvAh a visual ray. Bisect the anglescontained between the ray of light and the… … Fig. 145. point on the line of vision), bisect the angle LhAhClh with theline AhD\ Join ChLh and through the point D\ draw a hor.cutting ChLh at Df, then AhDlh is the hor. projection of thebisecting line. A plane drawn per. to this bisecting line andtangent to the sphere touches the surface at the…
