Abstract: An apparatus and method for adjusting the friction between a slide such as a ski and a responsive material such as snow by heating or cooling a portion of the material to change the material's coefficient of friction is disclosed. The apparatus includes a slide, a power source, and a thermal means which uses power from the power source to heat or cool the material the slide glides over. Electrical and chemical power sources are described. In one presently preferred embodiment, the slide is a ski, the power source includes electric batteries, and the thermal means includes heating elements embedded in the ski. The amount and location of heat produced may be controlled manually, remotely, or automatically. The batteries may be enclosed in the ski or attached to the skier's back. Other presently preferred embodiments include heated ice skate blades, snowmobile runners, and sled runners. Thermal means which heat the snow directly rather than heating the slide first are also disclosed.

Abstract: A device for producing a three dimensional landscape scene within a sand/fluid environment. The device comprises a pair of plates having opposing interior surfaces which define an enclosed plate volume. These surfaces are separated by a distance of 0.02 to 0.06 inches to create a controlled environment conductive for random flow of a variety of sand or particle materials with differing densities and particle sizes. Particular particle sizes and dimensions are provided to enable resolution of colors as the particles fall within the fluid by force of gravity. Three dimensional detail is developed by reason of fine contrast particles cooperating in combination with shading particles and moderate sized particles all entrained within the liquid medium.