Light and Colour Theories, and their relation to light and colour standardization

The text develops a practical system for measuring and standardizing colour, arguing that colour is a determinable property and describing instruments and graded glass scales built from red, yellow and blue units. It outlines the evolution of the method and unit, explains derivation of colour from white light and proposes a standard white light for comparison. The author defines qualitative and quantitative nomenclature and shows how combinations of calibrated glass slips and equations produce reproducible colour matches. Colour charts, tintometrical plates and three‑dimensional representations illustrate procedures, while spectra, absorption and fading curves connect optical theory to industrial and physiological applications; appendices cover education and prospects for a universal unit.