Book 3 — Ruler with Round and Flat Edges

The Molding Presents a Round Edge for a Pen and a Flat One for a Pencil

Picking up a smooth piece of ordinary wood molding, intending to use it as a ruler, I found that its shape, A, combined the properties of the round ruler and flat ruler, as well as assuming the third position D. A simple reverse changes the edge from a round to a sharp or flat, accommodating it to a pen or pencil, as shown. Such a piece of molding can be procured from a local lumber dealer.—Contributed by James M. Kane, Doylestown, Pa.