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586,247 · Soper · "Prismatic Glass" · Page 2 Home  > Prism Glass  > Patent Index  > Page 2

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same length as before, and continue this operation until the whole line indicating the plane to be illuminated is covered, as indicated in Fig. 3. Equal quantities of light must be thrown between each pair of lines drawn from the position of the prism to the area to be illuminated. On an enlarged scale draw a line representing the width of the prism along its receiving-surface and divide this width into equal parts equal in number to the number of ares described above. Beginning at the point where the prism curve is to depart from the body of the glass draw a short line which will throw the light falling upon it from the lowest division measured on the receiving-surface upon the farthest area. Then lay off another short line from the end of this short line, which will throw all the light falling upon it from the next division measured on the receiving-surface to the next arc, and so on to the end. Then by connecting these several short lines in a proper manner the desired curve will be produced.

I claim—     As a new article of manufacture, a prism-light comprising a substantially flat body of glass with a receiving-surface on one side and a series of prisms on the opposite side, extending substantially across the body and systematically arranged to produce an increased illuminating effect in the apartment, each prism having two faces, one a plane face and the other a curved face, the curvature being other than the arc of a circle, and such, substantially as shown and described, that all the rays of light falling from a predetermined direction upon the receiving-surface pass into the body and are thence transmitted in such manner that equal quantities of such light fall on equal areas taken at different distances from the prism-light along a horizontal line. FRANK C. SOPER. Witnesses:     FRANCIS W. PARKER,     OLIN H. BASQUIN.