The Top-Figured Letter-Scale Beam: Read the Weight From Above

"In the drawings, A is the base; B, the standard; C, the tray, and D the beam, whose notches are on the upper side, as usual, being engaged by a projection in the slot of the pea or weight." "It is usual to put the figures denoting weight upon the flat and nearly vertical sides of the beam".

**Stand.** Screw a hardwood upright 15 cm tall to a plywood base and drill a hole near its top for a nail fulcrum. **Beam.** Saw a beam 30 × 2 × 1.5 cm from hardwood board, flat on top. Drill it for the nail 7 cm from one end. Hang a small plywood tray from that end on wire. **Pea.** Bend a wire saddle that sits on the beam, hang washers and a nut from it as the pea, and file small notches across the top of the beam where it will sit. **Figures.** Balance the empty scale by filing the heavier end. Put objects weighed on the kitchen scale in the tray, slide the pea until level, and mark each notch. Write each weight twice, the same size: once on the beam's side and once on its top. **Test.** Put the scale on a table. Have five people read a weight from where they would stand to weigh a letter, first from the side figures and then from the top; time each reading and note mistakes.

**Richard Murdoch** of Baltimore signed US 57,364 on 22 March 1866; it is dated 21 August 1866. His claim is letter scales "provided with a graduated beam having the figures upon its flat upper side". **Honest limits.** A hardwood beam, wire pea and nail fulcrum stand in for his metal scale. The notebook treats the eye as far from the scale compared with its size; its angles are examples. Your reading times are the result.