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
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