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 128
straight wire in a vertical direction passing through the apex of the triangle, and show that when so placed, it cuts or intersects the base exactly midway; but as a vertical line appears vertical, the apex evidently appears vertically above the middle of the base, and is therefore to be… … be exactly in the middle of the line representing the base, because the distant half of the base being further removed from the eye, forms at the eye a smaller visual angle than the nearer half of the base. First Position. The model in a vertical plane, parallel to the sides of the room, with the…
Drawing · Perspective
Internet Archive · Getty Research Institute · Public domain (published before 1931). Free to use for anything.
