Pierre Hérigone
Encyclopedia
Pierre Hérigone (1580–1643) was a French
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

 mathematician
Mathematics
Mathematics is the study of quantity, space, structure, and change. Mathematicians seek out patterns and formulate new conjectures. Mathematicians resolve the truth or falsity of conjectures by mathematical proofs, which are arguments sufficient to convince other mathematicians of their validity...

 and astronomer
Astronomy
Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...

.

Of Basque
Basque people
The Basques as an ethnic group, primarily inhabit an area traditionally known as the Basque Country , a region that is located around the western end of the Pyrenees on the coast of the Bay of Biscay and straddles parts of north-central Spain and south-western France.The Basques are known in the...

 origin, Hérigone taught in Paris
Paris
Paris is the capital and largest city in France, situated on the river Seine, in northern France, at the heart of the Île-de-France region...

 for most of his life.

Works

He is the author of Cursus mathematicus, nova, brevi, et clara methodo demonstratus, per notas reales et universales, citra usum cujuscunque idiomatis intellectu faciles (published in Paris in six volumes from 1634 to 1637; second edition 1644), a compendium of elementary mathematics
Elementary mathematics
Elementary mathematics consists of mathematics topics frequently taught at the primary or secondary school levels. The most basic topics in elementary mathematics are arithmetic and geometry...

 written in French
French language
French is a Romance language spoken as a first language in France, the Romandy region in Switzerland, Wallonia and Brussels in Belgium, Monaco, the regions of Quebec and Acadia in Canada, and by various communities elsewhere. Second-language speakers of French are distributed throughout many parts...

 and Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

. The work introduced a system of mathematical
Mathematical notation
Mathematical notation is a system of symbolic representations of mathematical objects and ideas. Mathematical notations are used in mathematics, the physical sciences, engineering, and economics...

 and logical notation. It has been said that "Hérigone introduced so many new symbols in this six-volume work that some suggest that the introduction of these symbols, rather than an effective mathematics text, was his goal." Florian Cajori
Florian Cajori
Florian Cajori was one of the most celebrated historians of mathematics in his day.- Biography :...

 has written that the work contains "a full recognition of the importance of notation and an almost reckless eagerness to introduce an exhaustive set of symbols..."
Hérigone may have been the first to introduce the mathematical symbol to express an angle
Angle
In geometry, an angle is the figure formed by two rays sharing a common endpoint, called the vertex of the angle.Angles are usually presumed to be in a Euclidean plane with the circle taken for standard with regard to direction. In fact, an angle is frequently viewed as a measure of an circular arc...

. He used both the symbol below and recorded the use of "<" as a symbol denoting "less than."


He also introduced the upside-down "T" symbol to express perpendicularity.

In regards to the notation for exponents, Herigone wrote a, a2, a3, etc. (though the numerals were not raised, however, as they are today).

Hérigone also created a number alphabet
Alphabet
An alphabet is a standard set of letters—basic written symbols or graphemes—each of which represents a phoneme in a spoken language, either as it exists now or as it was in the past. There are other systems, such as logographies, in which each character represents a word, morpheme, or semantic...

 for remembering long numbers in which phoneme
Phoneme
In a language or dialect, a phoneme is the smallest segmental unit of sound employed to form meaningful contrasts between utterances....

s were assigned to different numbers, while the vowel
Vowel
In phonetics, a vowel is a sound in spoken language, such as English ah! or oh! , pronounced with an open vocal tract so that there is no build-up of air pressure at any point above the glottis. This contrasts with consonants, such as English sh! , where there is a constriction or closure at some...

s were supplied by the memorizer: 1 (t, d), 2 (n), 3 (m), 4 (r), 5 (l), 6 (j, ch, sh), 7 (c, k, g), 8 (f, v, ph), 9 (p, b), 10 (z, s). (see article Herigone's mnemonic system).

In Hérigone's work, we find the earliest written examples of mathematical terms. Parallelipipedon, an archaic form of parallelepiped
Parallelepiped
In geometry, a parallelepiped is a three-dimensional figure formed by six parallelograms. By analogy, it relates to a parallelogram just as a cube relates to a square. In Euclidean geometry, its definition encompasses all four concepts...

, appears in an English
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

 work dated 1570. Hérigone himself used the spelling parallelepipedum.

Hérigone and the camera obscura

In the Cursus mathematicus, Hérigone describes a camera obscura
Camera obscura
The camera obscura is an optical device that projects an image of its surroundings on a screen. It is used in drawing and for entertainment, and was one of the inventions that led to photography. The device consists of a box or room with a hole in one side...

 in the form of a goblet (Chapter 6, page 113). Hérigone did not depict his goblet, but Johann Zahn
Johann Zahn
Johann Zahn was the seventeenth-century German author of Oculus Artificialis Teledioptricus Sive Telescopium...

 would illustrate the design in his Oculus Artificialis Teledioptricus Sive Telescopium (1685). Hérigone's goblet-camera obscura, more a novelty
Novelties
A novelty item is a small manufactured adornment, especially a personal adornment.- Novelty item :This term covers a range of small manufactured goods, such as*antiques*collectables*chocolates*esoterica*executive toys*gadgets*tools and implements...

 than anything else, was constructed in such a way that you could spy on others while taking a drink. The device's 45-degree angle mirror had a stylized opening for the lens. The goblet had a cup made of glass where images could be seen. The lid bore a magnifying lens at the top.http://www.precinemahistory.net/1650.htm The lens and mirror of this dinner table device for spying was situated at the base of the goblet's stem, and served to project a real-time image onto the ground glass screen in the cup of the goblet.

Committee work

Hérigone served on a number of scientific committees, including one set up to determine whether Jean-Baptiste Morin's scheme for determining longitude
Longitude
Longitude is a geographic coordinate that specifies the east-west position of a point on the Earth's surface. It is an angular measurement, usually expressed in degrees, minutes and seconds, and denoted by the Greek letter lambda ....

 from the Moon's motion was practical. Members of this committee included Étienne Pascal
Étienne Pascal
Étienne Pascal was the father of Blaise Pascal. His father and mother were Martin Pascal, the treasurer of France, and Marguerite Pascal de Mons. He also had three daughters, two of whom survived past childhood: Gilberte and Jacqueline...

 and Claude Mydorge
Claude Mydorge
Claude Mydorge was a French mathematician. His primary contributions were in geometry and physics.Mydorge served on a scientific committee set up to determine whether Jean-Baptiste Morin's scheme for determining longitude from the Moon's motion was practical.-External links:...

.

He died at Paris.

The crater Herigonius
Herigonius (crater)
Herigonius is a small lunar impact crater that is located in the southern part of the Oceanus Procellarum, to the northeast of the crater Gassendi. Herigonius is roughly circular, with an inward bulge and narrower inner wall along the northeast...

 on the Moon
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...

is named after him.

Sources

Biography of Pierre Herigone The History of the Discovery of Cinematography Earliest Uses of Symbols from Geometry Mathematical symbols Universal Language Earliest Uses of Symbols of Operation and Grouping ScienceNewsOnline (10/3/98) Earliest Known Uses of Some of the Words of Mathematics
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