AS is well known, it is difficult to compare the intensities of lights of different colour. We can tell when one is much brighter or much darker than the other, but values obtained for the point of ...

IIIF provides researchers rich metadata and media viewing options for comparison of works across cultural heritage collections. Visit the IIIF page to learn more. Flicker photometers are used to ...

MR. WALSH'S book may be regarded as a useful supplement to pre-War works on illumination. The text may be conveniently divided into four main sections. We have first an account of the effect of light ...