Skipping stones and method of use thereof

摘要

Skipping stones having characteristics enhancing their ability to skip a large number of times on the surface of a body of water and enhancing the distance they will travel across the water before sinking. The stones are formed of somewhat porous, cementitious material and have a lower, generally circular water engaging surface which is slightly dimpled in its near-center region and slightly convex in its near-edge region with a sharply convex peripheral edge and a generally cylindrical, slightly upwardly converging side wall, the configuration of the peripheral edge of the water engaging surface and the adjoining sidewall being such as to minimize surface tension induced suction on the stone, caused by the water across which the water engaging surface of the stone is moving. The upper surface of the stone is generally flat so as to readily distinguish it from its lower, water engaging surface. The stone suitably comprises a cast mixture of gypsum cement and fine sand in approximately equal parts by volume. For a stone of a given radius dimension R (with R suitably 7/8", for example), the average thickness is about 0.4 R, the depth of the dimple in the near-center region of the stone water engaging surface is about 0.04 R, the reduction in thickness in the convex near-edge region thereof at the peripheral edge is about 0. 1 R, and the angle of convergence of the sidewall is about 5°.