Antique Simmance Patent Flicker Photometer 991H Alex Wright & Co circa 1910-15

Antique Simmance Patent Flicker Photometer 991H by Alex Wright & Co circa 1910-15. Adjustable speed clockwork mechanism complete with winding key, prism and lenses. Comes with it`s revolving stand which is nice to see as they are often missing. Comes to you in excellent condition and appears in good working order. 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. We strive very hard to offer a fast and efficient service at all times. After all, a happy customer is potentially a returning customer. We will send you a combined invoice when you are finished purchasing.

However if you need more information on an item please request more specific details or photographs.

---