BUY PRINT    June 1942. "John Sonesen, propeller grinder at a Hartford, Connecticut, plant, inspects a blade for a vertical balance during the operation of grinding it to correct contours in a template. This Hamilton blade will be assembled in a pitch-controlling Hydra-Matic mechanism to help power one of our new warplanes." Photo by Andreas Feininger for the Office of War Information. | Click image for Comments. | Home | Browse All Photos