Colour Measurement and Mixture
CHAPTER III.
The Visible and Invisible Parts of the Spectrum--Methods for showing the Existence of the Invisible Portions--Phosphorescence--Photography of the Dark Rays--Thermo-Electric Currents p. 30
Colour Measurement and Mixture
The Visible and Invisible Parts of the Spectrum--Methods for showing the Existence of the Invisible Portions--Phosphorescence--Photography of the Dark Rays--Thermo-Electric Currents p. 30