HOW_TO_BUILD_A_ROCKER_BOX
· Rocker Box. This plan is reprinted from Information Circular 6786, "Placer Mining in the Western United States" by E. D. Gardener and C. H. Johnson. It was published by the US Bureau of Mines in September, 1934 . More gravel can be handled per man-day by rocking, or cradling as it is sometimes called, than by panning.