Abstract
The procedure of calibrating a ruled scale and of measuring the magnification of a visible light microscope is described. The measurement techniques include the use of: (1) a movable hairline micrometer, (2) an image-splitting ocular, (3) photoelectric scanning of photomicrographic plates, and (4) photoelectric scanning of the image plane. An empirical treatment of the magnification measurements, including the effects of optical distortion, is employed, so that the residual errors are assigned to the imperfections in the measuring screw plus the random contributions.

This publication has 5 references indexed in Scilit: