He was born in
Ornans, France, in 1580. He was taught science by his father. He became captain and castellan of the castle at Ornans, for the King of Spain. He was also later councillor and director general of economy in the
County of Burgundy. In
Brussels, in the year 1631, Vernier published his treatise ''La construction, l'usage, et les propriétés du quadrant nouveau de mathématique'', and dedicated it to the
Infanta. In it, he described the ingenious device which now bears his name, the
vernier scale. To a
quadrant with a primary scale in half degrees Vernier proposed to attach a movable sector, thirty-one half degrees in length but divided into thirty equal parts (each part therefore consisting of a half-degree plus one minute). In measuring an angle, minutes could be easily reckoned by noticing which division line of the sector coincided with a division line of the quadrant.
Christopher Clavius had earlier mentioned this idea but had not proposed to attach the scale permanently to the instrument. The name
vernier is now applied to the small movable scale attached to a
caliper,
sextant,
barometer, or other graduated instrument and was given by
Jérôme Lalande. Lalande showed that the previous name,
nonius after
Pedro Nunes, belonged more properly to a
different contrivance. The name
nonius continued to be applied to the vernier until the beginning of the 19th century. ==Notes==