The Pen-Rack Letter Balance: Pens, Calendar and Scale on One Stand

"A A in the drawings, Figure 1, are the sides of the pen-rack, a side view of which is shown in Fig. 2. B is a cylinder, constructed of any suitable material, occupying the space between the said sides of the pen-rack." "The letter-balance or weighing-scale may be of any description—a simple balanced lever, as in the drawings, a platform, or any other kind of a scale. In the drawings, D is a balanced lever. E is the fulcrum. F is a stop to prevent the lever from rising too high, and G is the letter-holder which is movable from one notch to another."

**Rack.** Cut two plywood sides 15 × 10 cm and cut a row of pen notches in their top edges. Cut 15 cm of PVC pipe as the cylinder and bolt the sides to its ends with threaded rod, nuts and washers through it. **Calendar.** Cut three strips of card stock to wrap loosely round the pipe as rings; write the weekdays round one, the months round the second and 1 to 31 round the third. Cut a window in a card band glued over them so one entry on each ring shows. **Lever.** Cut 25 cm of hardwood strip, drill it across 5 cm from one end for a nail fulcrum, and rest the nail in notches in two blocks glued on top of the rack. Tape washers 4 cm from the fulcrum as the counterweight. Glue a small block above the lever as the stop. **Notches.** Clip a binder clip on the long arm as the letter holder. Hang objects weighed on the kitchen scale at 14 g, 28 g, 57 g and 85 g in it, slide it until the lever just tips, and file a notch there. Compare with the notebook.

**Horatio N. Taft** of Washington, D.C., received US 45,770, dated 3 January 1865 and antedated 27 November 1864. His rings could also be disks of wood on the screw bolt, turned through the rack's sides, and he wrote that the balance could be of any kind. His claims cover the calendar and its combination with the pen rack, and the balance combined with calendar and rack. **Honest limits.** Plywood, PVC pipe, card rings and a hardwood lever stand in for his rack, cylinder, rings and lever. The notebook ignores the lever's own imbalance, which is why the notches are marked by test; its weights and distances are examples. Your notches are the result.