Abstract: A portable pool cleaning system for cleaning the surfaces of swimming pools and surrounding decks without draining the pool water. The system includes a cart for containing an electrically powered pump, a line to an external source of muriatic acid or another suitable swimming pool cleaning agent and a line to a clean water source. The system also includes a cleaning wand having a cleaning head for engagement with the pool walls and floor. A valving system is used to regulate the flow of a cleaning agent through the system, to dilute the muriatic acid with water from the clean water source, and to recirculate through the system any unused portion of muriatic acid which is prevented from flowing to the cleaning wand. The valving system further allows the operator to flush the system with clean water before withdrawing the cleaning wand from the pool water.

Abstract: An indicator device to inform golfers of the position of the cup on the green and other play aspects of a hole of a golf course. It has a display panel carrying a graphic representation of the hole including the tee and green, a grid of electrically energizable indicators associated with the green representation, an array of electrically energizable indicators associated with the tee representation and electrical circuitry for energizing predetermined indicators in the grid and the array.

Abstract: An educational device for use in instruction concerning solar heat utilization comprises a solar energy collector in which liquid is heated by solar energy indirectly through a heat-exchanger, a liquid storage tank, a pump and associated pipe system to circulate liquid between the collector and the storage tank, a valved by-pass line to permit recycle of liquid from and to the storage tank external of said collector and an instrument panel to display temperature of said heat exchanger, temperature of liquid contained within said collector, temperature of liquid contained in said storage tank and pressure of liquid flowing in said pipe system.