Abstract
DR. H. W. MELVILLE prepared an evening lecture for the Dundee meeting of the British Association, under the title “New Lamps for Old” The natural illuminant, the sun, is considered first. We may regard the sun as a ‘black body’ with a surface temperature of about 6000° C. Being a black body, it emits light of all wave-lengths, but the wave-lengths in which we are particularly interested lie in the visible region from about 4000 A. to 7500 A., for it so happens that evolutionary processes have developed a human optical system which is most sensitive to such a band of wavelengths.
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Progress of Illumination. Nature 144, 604–605 (1939). https://doi.org/10.1038/144604a0
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DOI: https://doi.org/10.1038/144604a0