The science of illumination : an outline of the principles of artificial lighting / by Dr. L. Bloch ; translated by W. C. Clinton.

  • Bloch, Leopold.
Date:
1912
Catalogue details

Licence: In copyright

Credit: The science of illumination : an outline of the principles of artificial lighting / by Dr. L. Bloch ; translated by W. C. Clinton. Source: Wellcome Collection.

Provider: This material has been provided by UCL Library Services. The original may be consulted at UCL (University College London)

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    TABLE II. Photometric Magnitude. Symbol. Unit. Equation of Definition. 1. Intensity of light / Candle F 1= CO 2. Luminous flux F Lumen IS F*=I<o = ^ = ES=ttQ 3. Illumination E ''Lumens milli lumens F F° 1 < 2 or o cm cm2 4. Radiation ... E \ Lux = meter-candle Fi E' = — — irb = mE 5. Brightness b Candles cm2 S cos e 6. Quantity ... Q Candles Q = bS 7- Lighting ... L Lumen hours L = FT % — angle of incidence of light ^ measured i^: = incident flux. e = angle of emergence of light j f rom normal. Fe — emergent flux. ?w = coefficient of diffuse reflection or transmission. (1 - m) = coefficient of absorption.