This photo was separated from the Engineer's correspondence - Penstocks and Dams (various) [#9] 1888-1913.
Title (generic)
Print, Photographic
"11' Pemberton Penstocks, July 19, 1908. Built in fall of 1896 coated with (illegible). Cleared area showed 60 pits per square foot, the pits averaging about 40/1000 inch in depth and covering about 20% of the area of the plate."
Collection
Essex Company Photographic Print Collection
Date (coverage)
1908-07-19