An elongated frame adapted to be attached to a vertical supporting surface, said frame having a length and including a front face Ī recess centrally disposed in the front face of said frame, said recess including a metallic surface and extending substantially along the length of said frame Īt least one graduated scale attached to the front face of the frame adjacent said recess Ī magnetic block movably disposed within said recess andĪ block member hingedly connected to said magnetic block, said block member being horizontally pivotably and having a straight edge for aligning with said at least one graduated scale.Ģ.
