Rolling Rules by the Dozen, German, c. mid-20th c., the 12-1/2″ x 11-3/4″ (32 x 30 cm) fabric-covered fitted wood case containing a salesman’s full diversity of 14 opisometers. Most have plated brass handles and mounts, and colored paper dials (recording Inches to Miles or Centimeters to Kilometers, or Nautical Miles, or Russian Verstes, etc.), and are two-sided. Each has a small rolling wheel geared to the hand(s), in order to measure, and convert, distances on a chart or
Read More...