Of the six colours in white light—red, orange, yellow, green, blue and violet; Red, Yellow and Blue are regarded as dominants, because they visually hold the associated colours orange, green and violet in subjection.
An equivalent unit of pure red, pure yellow and pure blue is adopted, and incorporated into glass. The unit is multiplied to obtain greater intensities, and divided to obtain lesser intensities.
The coloured glasses are called absorbents. The red absorbent transmits violet, red and orange, but the red ray alone is visible as colour, until the other absorbents are superimposed, and the character of the group of rays changed. In the same way yellow transmits orange and green, and blue transmits green and violet, whilst the yellow and blue alone are visible as colour. Orange, green and violet are here called subordinates, which may be developed as follows:—
Or. = R. + Y. Gr. = Y. + B. Vi. = B. + R.
Twenty-five years’ experience in the application of the theory and the method to the requirements of practical work, have given no reason for change. Following will be found a list of awards from International Juries and Scientific Societies, also a list of industries in which the writer’s method is giving entire satisfaction.
| Awards by International Juries. | |
| St. Louis | 1 Silver Medal. 2 Bronze Medals. |
| Brussels | 1 Gold Medal. 3 Silver Medals. |
| Turin | Diploma of Honour. 1 Gold Medal. 1 Silver Medal. |
Awards by Scientific Societies.
Sanitary Institute of Great Britain—
Bronze Medal for Colourometrical Water Analysis.
Royal Sanitary Institute—
Bronze Medal for Measuring Smoke Densities.