Caption:
Malayan Tin - Gravel Pump And Hydraulicing - The typical Gravel pump structure viewed from the tailings area. The alluvial tin-bearing soil is washed into a pit at the other end, drawn up by suction of the gravel pump and the flow of water over the main palong washes off the lighter soils and leaves the alluvial tin deposits to be collected. July 01, 1951. (Photo by British Official Photograph).