Abstract: A robotic tractor that travels on rails forming a grid over a crop field and automatically performs tasks in the field is described. The tractor is supported on extendable legs that carry dual tandem perpendicular wheel sets. A rotary implement bed supported by the tractor is adapted to carry implements.

Abstract: A soilless agricultural system and components therefore including a hydroponic assembly comprising support means for defining a crop field, nutrient solution circulating system and a plant tray assembly having a seedling or plant tray cooperating with a support tray.

Abstract: A light-transmissive solar insulating block assembly comprising: light-transmissive insulating block means defining at least one internal cavity for insulating the interior of a structure to be heated; a housing having a light-transmissive cover providing an exterior surface and a plurality of support walls extending between and separating said cover and said block means, said housing cooperating with said block means to define a circulation chamber therebetween, said support walls defining a plurality of passageways for ingress and egress of air into and out of said chamber; and control means operatively pivotally connected to said housing for reflecting radiant heat back into the interior of the structure being heated controlling the amount of light passing through said chamber, and structures constructed from an array of said block assemblies.

Abstract: A hand catapult including a shaped handle designed to conform to the hand of the user, a semi-circular carriage secured to the top of the handle in offset relationship to the longitudinal axis of the handle, resilient band for hurling a missile, and swivel carriage bindings for connecting the resilient band to the carriage. The handle includes handle core to provide heft and weight for improved feel and handling and to permit various accessories to be attached easily to the handle. The accessories may include a leather carrying strap, a wrist brace to provide greater stability for better aiming, and an ammunition tube attachment.