Pierre Vernier

Pierre Vernier, born at Ornans in Franche-Comté, then ruled by the Spanish Habsburgs and now part of France, on 19 August 1580 and dead there on 14 September 1637, was a mathematician and instrument inventor, the inventor and eponym of the vernier scale used in measuring devices. Taught science by his father, he became captain and castellan of the castle at Ornans for the King of Spain and later councillor and director general of economy in the County of Burgundy. In Brussels in 1631 he published his treatise La construction, l'usage, et les propriétés du quadrant nouveau de mathématique, dedicated to the Infanta, in which he described the device that bears his name: a movable sector thirty-one half degrees long, divided into thirty equal parts, attached to a quadrant with a primary scale in half degrees, so that minutes can be read from the coinciding division lines. Christopher Clavius had earlier mentioned the idea but had not proposed attaching the scale permanently to the instrument.