Stanley Boucher Pocket Watch Style Circular Slide Rule Calculator. Early & Scarce/Collectable Stanley Boucher Slide Rule Pocket Watch style Calculator, c1900.The Boucher Calculator pocket-watch style slide rule, patented in 1876, is the first pocket-watch style slide rule, and the design most copied by other makers. The Boucher went through several designs and has had many makers (some were certainly just retailers) names on it, but no one knows for sure who made any of them. This Boucher Calculator is labeled Stanley, Maker, London. It is in excellent working condition, but cosmetically there is a small rust mark to the paper scales on one side and some of the nickel plating tarnish spots otherwise nickel plate is complete no loss. The front and rear beveled glass crystals are perfectly flat, not domed, and scratch-free one side has machine etched inner circle to glass. Both knobs work perfectly, rotating the scales and pointers through full revolutions in both directions. On the front, the Stanley, Maker, London side, the top knob rotates the scales, and the side knob turns the movable pointer. On the back, the Boucher Calculator side, the scales are fixed and the top knob does nothing; the side knob rotates the movable pointer as on the front.
Both movable pointers rotate together and are aligned with each other. The diameter of the Boucher is 2, or 50 mm approx.
Apart from the rust patch to dial this is a very nice example. P&p domestic & international will be signed for. Stanley Boucher Pocket Watch Style Circular Slide Rule Calculator" is in sale since Wednesday, April 17, 2019. This item is in the category "Antiques\Science/Medicine\Scientific Instruments".
The seller is "aworldaway" and is located in scarborough north yorkshire. This item can be shipped worldwide.