Abstract: The subject invention provides for an educational device for teaching concepts of geography and biology (including ecology). The subject invention comprises a plant growth chamber in which any of a variety of plants may be grown. Covering the plant growth chamber is a plant growth limitation shield having at least one opening. The top surface of the plant growth limitation shield contains an illustration in which the aperture (or apertures) forms a part of the illustration. The subject device also comprises means for holding the plant growth limitation shield in place over the plant growth chamber such that plants growing from the plant growth chamber may grow through the aperture (or apertures) of the plant growth limitation shield and that the plant growth limitation shield is held in fixed position relative to the plant growth chamber.

Abstract: A plant maintenance control system designed to be effectuated through use of a computer; the basic aspect of the system relates to the unique results obtainable through particular operations performed by the computer based upon the unique organization and arrangement of the so-called data base complex, such that efficient and detailed control of maintenance expenses for a complicated chemical plant or the like can be readily established.