Description

An oxidised and lacquered brass, mahogany cased SIMMANCE PATENT FLICKER PHOTOMETER, circa 1915 Adjustable speed clockwork mechanism complete with winding key, prism and lenses. In excellent conditiom and good working order. Original pillar mounted on later cast iron stand. ********************************* Photometers of the flicker type are of particular use where it is necessary to compare the intensities of two sources of light, as light enters at each side of the photometer. The distance between the photometer and one of the sources of light can be adjusted (ie you move the light) until the two light sources appear equally bright when viewed through the photometer. The ratio of the intensities from the distances from each light to the photometer can then be calculated.