invention the device can be constructed from a variety of materials and in a variety of shapes and sizes so the embodiments shown should not be interpreted as being limited in these and other areas in particular the members may be constructed from wood marble fiberglass or other conventionally available materials of construction the structure 10 comprises a first member 12 and a second member 14 that are interconnected by hinge means 16 for permitting the first and second members 12 and 14 to angularly adjust relative to one another the hinge means 16 may comprise a conventional hinge as shown or it might be some other conventional design the first member 12 is further defined by a an edge 18 having one or more inclination selection apertures 24 disposed therealong the second member 14 is also defined by an edge 26 and is further defined by a first inclinable surface 30 the edge 26 also has one or more inclination selection apertures 28 disposed therealong these apertures 24 and 28 might in alternate embodiments consist of pegs or other devices for attaching the strut 29 to it should be intuitively apparent that the strut 29 and apertures 24 and 28 cooperate to enable the second member 14 to be positioned in a variety of angular positions relative to the first member 12 now turning to fig2 a and 2b we can examine the operation of the.