The Armstrong scale: a hypothesis
Among the more ubiquitous instruments named after their inventors - from Captain Field's parallel to the Napier compass, Gunter's chain to Marquois' triangles - arguably the most widely-known and numerous…
Thornton on folding pocket rules
I recently took a gamble on a job lot of plastic slide rules and other oddments on account of a blurry pocket rule in one corner of the photo. Superficially…