A fine John Rabone & Sons 24 inch folding boxwood ruler with brass slide rule with scales and charts according to I. Routledge, Engineer c.1870. Tight, with locating pins intact, brass protractor on hinge from 0-180 degrees, charts for cylinders, polygons, circles, metals, water, pumping engines, etc. Linear scales in inches, fractions of inches, cm., mm. Functional slide rule with every conceivable calculation for the engineer of the day. Brass tips on ruler, no chips or cracks. Near pristine example
Ask the Dealer
Mark Hacking (Scientifica Opticae Inc.) has been an avid collector/dealer for over 30 years. A former Science teacher, he has an innate love for anything natural or mechanical. Specializing in optical (microscopes, telescopes), surveying, medical, weighing and drawing instruments, he is an active participant of the Scientific Instrument Fair in London. Living in Stratford, Ontario, Canada, with his wife and two children; Mark looks forward to meeting as many fellow collectors as possible, and has a worldwide following on eBay (Sciopti).
Other items See all
- ~STUNNING PURE SILVER COINAGE and APOTHECARY SCALES~ 700 US (OBO)