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Sunday, February 23rd, 2025
the Seventh Sunday after Epiphany
the Seventh Sunday after Epiphany
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Bible Encyclopedias
Actinometer
1911 Encyclopedia Britannica
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(Gr. &KTis, ray, p rpov, measure), an instrument for measuring the heating and chemical effects of light. The name was first given by Sir John Herschel to an apparatus for measuring the heating effect of solar rays (Edin. Journ.. Science, 1825); Herschel's instrument has since been discarded in favour of the pyrheliometer (Gr. rvp, fire, i Xeos, sun). (See Radiation.) The word actinometer is now usually applied to instruments for measuring the actinic or chemical effect of luminous rays; their action generally depends upon photochemical changes (see Photo-Chemistry). Certain practical forms are described in the article Photography.
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These files are public domain.
These files are public domain.
Bibliography Information
Chisholm, Hugh, General Editor. Entry for 'Actinometer'. 1911 Encyclopedia Britanica. https://www.studylight.org/encyclopedias/eng/bri/a/actinometer.html. 1910.
Chisholm, Hugh, General Editor. Entry for 'Actinometer'. 1911 Encyclopedia Britanica. https://www.studylight.org/encyclopedias/eng/bri/a/actinometer.html. 1910.
