File:Colour Photometry. Part III (1892) (14785008013).jpg

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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¢4 1*7 § L.âLuminosity of a Spectrum produced by Feeble Light. Having found that the persistency curve was apparently and presumably the sameas the luminosity curve of the two persons who had but one colour sensation, it almostfollowed that if the beam of light producing the spectrum were sufficiently reducedits curve of luminosity would approach these. An experiment was therefore made.The reference beam was introduced into the measuring box already described (fig. 36),and, when uninterrupted by the sectors, had a luminosity of T3V5 °f an amyllamp at one foot off. The beams from the spectrum of the colour patch apparatuswere also introduced into the apparatus so that they fell as before on S. The luminosityof the different rays was taken in the ordinary manner interposing the rotatingsectors in the reference beam. The following results were obtained (see Table XI),the mean of the readings being given. This mean in Column III. is multiplied by 1*25 ON COLOUR PHOTOMETRY, 557 Fi* 44,
Text Appearing After Image:
Extinction and luminosity curves of a red blind. Fig. 45.

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