Spanton, J. Humphrey (John Humphrey) · London, Macmillan and Co., Limited; New York, The Macmillan Company · leaf 121
a circular opening ina piece of thin card-board or stiffpaper, and place it a short dis-tance from a lighted candle ; thiswill form a cone of light (Fig.215). If we place a plane, e.g.a piece of paper pinned to adrawing-board, so as to allowthe hght coming through thecircular aperture to fall upon… … GEOMETRICAL DRAWING AND DESIGN. In Fig-. 215 the plane is parallel to the aperture, so the sectionobtained is a circle.
Geometrical drawing · Design · Drawing
Internet Archive · Wellesley College Library · Public Domain Mark 1.0. Free to use for anything.
