PERSPECTOGRAPH (Milton Bradley perspective drawing apparatus)

"Learn to draw easily with a PERSPECTOGRAPH...Twelve sample lessons and over fifty different objects - easily drawn with the new aid for everybody interested in perspective drawing"Springfield, MA: Milton Bradley Co., 1940. First Edition. Very good. Portfolio of 13 plates, 9 x 12 inches, printed recto-only. Title plate with instructions + 12 lessons. Very Good with bumping to the corners, light soil to exterior. Lesson 9 has the perspective lines drawn on in pencil; others unmarked. Covers fold out to form an apparatus with two black rulers hinged at the outside panels. The center panel is lined with graduated rulers and slit in each corner so that paper can be secured. A few cards also include cutout patterns to build cubes and cones for practicing observational drawing.The lessons emphasize architectural drafting, with basic perspective covered before introducing ellipses and curvilinear perspective. A simplified version of the centuries-old apparatus credited to Leonardo da Vinci, p