Hurter and Driffield Actinograph, small mahogany box containing exposure calculator and an original carton by Marion and Co. Hurter and Driffield Actinograph and Original Carton 1885-1920
Hurter and Driffield actinograph, sold by Marion and CO. , London. Wooden slide-rule calculator; sliding card scale for time of month and day, N. lat 32 degrees 30'. Calibrated for H and D speeds, 0.5-300; lighting, f no. exp time. Hurter and Driffield actinograph