Watkin's Standard exposure meter (1900 pattern). Watkin's Standard exposure meter (1900 pattern) 1900
Watkin's Bee Meter. Watchform actinometer. In original box with instructions (12th edition) Watkins Bee Meter
Watkins Bee exposure meter with instructions and speed card, 1926. Watkins Bee Exposure Meter with Instructions and Speed Card 1926
Watkins' calculating shutter, fitted to Bausch & Lomb Optical Co. shutter). Watkins' Calculating Shutter
Watkins' exposure meter, (earliest experimental model of 1889). Watkins' Experimental Exposure Meter 1889
Watkins "Bee" exposure meter with original box and instructions and separate dial for autochromes. Watkins "Bee" Exposure Meter with Original Box and Instructions
Watkins dial meter experimental model, Hereford, England, c. 1900. Watkins Dial Meter Experimental Model 1900
Watkins exposure meter, barrel type with chain; shorter variety. Watkins Exposure Meter, Barrel Type with Chain
Watkins' experimental testing tank for testing plates in stages of development for their temperature coefficient. Watkins' Experimental Testing Tank
Special Watkin's Diaphragm designed to give equal spaces between U.S. values for a calculating shutter, c. 1902. Special Watkin's Diaphragm designed to give equal spaces between U.S. values for a calculating shutter 1902
Watkins Factorial calculator. Development calculator - two concentric discs bearing scales 1-50 (factors) 1 1/4-50secs. - time of appearance of image. Aluminium; [with joint instruction book for darkroom clock and calculator]. Watkins factorial calculator