Protected pivot adjustable scaled compasses

A protected pivot adjustable scaled compass comprising a molded plastic ruler-like body with an elongated slot along its centerline, said body having scales along the edges thereof, said body having means for a retractable spring loaded protected pivot at one end of said body, said protected pivot made of transparent material in the form of a button and scribed with cross hairs, a molded slide of transparent material that fits within said body slot and overlaps said body scales, said slide having a plurality of holes at the edges aligned with said centerline, hairlines inscribed in said slide, normal to the slide and body centerline which intersect said holes in said slide, said body having on its upper surface grooves parallel to said elongated slot on either side thereof, and said slide having means mating with said grooves for sliding movement therealong, a hole through the center of said slide that permits the insertion of a locking screw with a flat head that engages an elongated recess in the body along said slot in the bottom surface of said body, said screw passes through the slide and engages a thumb nut, further comprising a precise thickness washer having a hole in its center that fits over the locking screw, said washer has a diameter the same as said locking screw head, said washer capable of being positioned below said body and slide, one side of the washer resting in said recess of the body slot and the other side of the washer resting against the underside of the head of the locking screw with said locking screw passing through holes in said washer and slide and engaging said thumb nut, or alternately said washer capable of being positioned above said body and slide, one side of said washer resting on top of the slide and the other side of the washer resting against the bottom of the thumb nut, with locking screw passing through said holes in said slide and washer and engaging the thumb nut, thereby permitting an adjustment in height of the body and slide above the surface to be marked in the former position when using ink to prevent a smear and permitting an adjustment in height of the body and slide so that the body and slide rest on the marking surface in the latter position when using a pencil or scribe for increased accuracy, the thumb nut being tightened to lock the slide in both positions.