140. Watkins' Studio Special Bee Meter with Carton, c. 1905
Signed: 'WATKINS / STUDIO / METER / F. DIAL'.
Similar to operation as the Wynne actinometer. The scales are f stops 4 to 32, light values 2 to 180, and plate exposures from 1/30 to 1/500 sec. The albumen paper used in the early actinometers darkes to a brown tint, while later tintmeters with bluish-grey tints used bromide paper.
Diameter 43 mm, depth 10 mm.
Inventory no. 84,432.