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…
Rules are made to be broken
When is a rule not a rule? When it's four rules! This deceptively simple rolling ruler offers an unexpected "twist" on the conventional design. Made of what appears to be…