Abstract: The invention comprises a generally rectangular plate and a mounting system so that the plate can be mounted adjacent to and parallel to one wall of a fish containing enclosure, such as an aquarium. An elongated nozzle and water conduit are attached to one edge of the plate. In use, the nozzle directs a curtain of water transversely across the plate within the volume defined by the plate and enclosure wall. Fish are generally attracted to this faster moving water and preferentially move into the volume between the plate and enclosure wall. In an aquarium, this places them in a close up position where they can be easily watched by an observer.

Abstract: The invention is a viewing device suitable as a novelty item or for such other purposes as a teaching or navigational aid. It comprises a compass and in its preferred form has a 360.degree. panoramic photograph wrapped into drum form and affixed to the compass. A viewing device is also provided, so that when the person observing the photograph is facing a given compass direction, he will see essentially the same view that would be seen by another observer facing in the same compass direction at the point at which the photograph was taken. An essential part of the invention is the way the photograph is represented. If the viewing device is arranged to see the outside surface of the drum-shaped photograph, the photograph must be a mirror-image representation. If the viewing means is arranged to see the inside surface of the drum-shaped photograph, a normal representation must be used. In other versions of the invention, the photographs need not have edge-to-edge continuity.

Abstract: The invention is a highly maneuverable prime mover adapted for normal or orthogonal steering modes. In the normal mode true Ackermann steering is achieved. Either two or four wheel steering may be chosen. When in the orthogonal mode the vehicle is hybrid skid steered. In hybrid steering only one wheel of a side-by-side pair is steered. This greatly simplifies the necessary shifting mechanisms. Each wheel is driven by an individual hydraulic motor supplied from a main system. In the preferred version the prime mover has a turret capable of 360.degree. rotation. This turret preferably has a universal mounting capable of holding various types of lifting tools. The prime mover is especially well adapted for use with a tool head comprising an array of parallel screws or chains which can rapidly pick up, transport, and deposit objects such as container grown nursery plants.

Abstract: The disclosure relates to a secure locking mechanism for a sliding door or window. It comprises a toggling pair of bars, one of which is attached to the door frame and the other to the casing so that the bar lies across the fixed pane. The first bar is an inverted channel which encloses a portion of a second preferably solid bar. A pair of longitudinally side by side holes is drilled through both bars in the overlapping portion. The bars are joined in this area by one or more pins inserted through the holes. One hole is located adjacent to the distal end of the solid bar so that it can act as a pivot when the bars are united by a pin passing through this hole. The bars can then toggle to permit the door to be opened. If both holes are pinned or if a single pin is placed so that it passes through the other hole in the solid bar the assembly is securely locked.