Pierre Vernier (19 August 1580 at

Ornans Ornans () is a commune in the Doubs department in the Bourgogne-Franche-Comté region in eastern France. On January 1, 2016, the former commune Bonnevaux-le-Prieuré was merged into Ornans. Franche-Comté (at that time ruled by the

Spanish Habsburgs Habsburg Spain is a contemporary historiographical term referring to the huge extent of territories (including modern-day Spain, a piece of south-east France, eventually Portugal, and many other lands outside of the Iberian Peninsula) ruled b ...

, now part of

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...

) – 14 September 1637, same location) was a French

mathematician A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, structure, space, models, and change. History On ...

and instrument-inventor. He was the inventor and

eponym An eponym is a person, a place, or a thing after whom or which someone or something is, or is believed to be, named. The adjectives which are derived from the word eponym include ''eponymous'' and ''eponymic''. Usage of the word The term ''epon ...

of the vernier scale used in measuring devices.

Life

He was born in

Brussels Brussels (french: Bruxelles or ; nl, Brussel ), officially the Brussels-Capital Region (All text and all but one graphic show the English name as Brussels-Capital Region.) (french: link=no, Région de Bruxelles-Capitale; nl, link=no, Bruss ...

, 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 ''Infante'' (, ; f. ''infanta''), also anglicised as Infant or translated as Prince, is the title and rank given in the Iberian kingdoms of Spain (including the predecessor kingdoms of Aragon, Castile, Navarre, and León) and Portugal to th ...

. 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 consisting then 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 Christopher Clavius, SJ (25 March 1538 – 6 February 1612) was a Jesuit German mathematician, head of mathematicians at the Collegio Romano, and astronomer who was a member of the Vatican commission that accepted the proposed calendar inve ...

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 A sextant is a doubly reflecting navigation instrument that measures the angular distance between two visible objects. The primary use of a sextant is to measure the angle between an astronomical object and the horizon for the purposes of ce ...

barometer A barometer is a scientific instrument that is used to measure air pressure in a certain environment. Pressure tendency can forecast short term changes in the weather. Many measurements of air pressure are used within surface weather analysis ...

, or other graduated instrument and was given by Jérôme Lalande. Lalande showed that the previous name, ''nonius'' after

Pedro Nunes Pedro Nunes (; Latin: ''Petrus Nonius''; 1502 – 11 August 1578) was a Portuguese mathematician, cosmographer, and professor, from a New Christian (of Jewish origin) family. Considered one of the greatest mathematicians of his time, Nun ...

, belonged more properly to a different contrivance. From p. 859: ''"La division qui est aujourd'hui la plus employée est appellée dans plusieurs Auteurs ''division de Nonnius'', quoique Nonnius n'en soit pas l'Auteur; mais il en avoit imaginé une autre qui eut beaucoup de célébrité, & qui pouvoit conduire à celle que nous avons aujourd'hui. Le véritable Auteur de la nôtre fut Pierre Vernier qui la publia dans un petit Ouvrage imprimé à Bruxelles en 1631."'' (The scale which is most used today is called by many authors "Nonnius' scale", although Nonnius is not the inventor of it; but he had imagined another one which was very well known and which could have led to what we have today. The true inventor of our calewas Pierre Vernier who published it in a small work in Brussels in 1631.) The name ''nonius'' continued to be applied to the vernier until the beginning of the 19th century.Daumas, Maurice, ''Scientific Instruments of the Seventeenth and Eighteenth Centuries and Their Makers'', Portman Books, London 1989

Notes

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External links

* {{DEFAULTSORT:Vernier, Pierre 1580 births 1637 deaths People from Doubs 17th-century French mathematicians 17th-century French inventors French scientific instrument makers Inventors from the Holy Roman Empire Scientific instrument makers from the Holy Roman Empire Mathematicians from the Holy Roman Empire