A New Earth-Shaking Machine

Extract

In the fall of 1954 the undersigned had occasion to investigate the discovery of an eastern fluted projectile point in an excavation being made for the erection of a flagpole memorial to the man who originated the Tadpole Club. In preparation for this expedition to a Boy Scout camp near the Delaware Water Gap we decided to build a motor-driven sifter. This machine has operated so well on this and succeeding trips that it seems to warrant a brief description.

The accompaning sketch (Fig. 128) shows the basic principles. The screen, mounted at a slant on 1/4-inch thick plywood legs, is free to move back and forth due to the flexibility of the plywood. A little experimentation demonstrated that about 150 strokes was right for most sifting operations.