A manual for teaching model-drawing : from solid forms, the models founded on those of M. Dupuis : combined with a popular view of perspective, and adapted to the elementary instruction of classes in schools and public institutions (1843)
Williams, J. Butler, Sir, Lowry, Joseph Wilson, 1803-1879 · London : J. W. Parker · leaf 172
151 IN PERSPECTIVE DRAWING. 2. To estimate the appai%ent Inclination of Lines. The Sight-rule. The annexed diagram repre- sents a simple instrument well adapted for deter- mining the apparent inclination of lines. The side arms revolve round a pivot at the upper part of the case, which is hollowed… … Shut. Open tor use. but yet with sufficient stiffness to remain at any angle without shifting by their own weight. To determine, by the sight-rule, the apparent inclination of a line, the middle part or case is held upright between the eye and one extremity of the line; and one of the arms being…
Drawing · Perspective
Internet Archive · Getty Research Institute · Public domain (published before 1931). Free to use for anything.
