Identifier: philtrans04238067 (find matches)
Title: Colour Photometry. Part III
Year: 1892 (1890s)
Authors: Abney, W. Festing, E.
Subjects: Proceedings of the Royal Society of London Philosophical Transactions of the Royal Society
Publisher: Royal Society of London

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Text Appearing Before Image:
Extinction and luminosity curves of a red blind. Fig. 45.
Text Appearing After Image:
Luminosity to a normal eye of a feeble spectrum. 558 CAPTAIN W. DE W. ABNEY AND MAJOR-GENERAL E. R. EESTING to bring the maximum to 100. This curve (fig. 45), that of the monochromatic sensa-tion, and the persistency curve are tabulated together in Table X., to show how closelythey agree. Here we have a proof that the normal eye is as little sensitive to the redend of the spectrum formed from a very much reduced light as those of the two brotherswhen ordinary light is used. It must be remarked, however, that all colour was notentirely absent, though it was very considerably reduced in saturation. The measure-ments were made with some trouble at first, owing to the inclination of the eye todirect its axis to some point other than the centre of the patch where the white stripand the colour strip touch one another. The diversion of the axis of the eye in somecases made the colour more luminous, and in other cases less so, than it did when theeye was properly directed, as might be surmise

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