Person: Hérigone, Pierre
Pierre Hérigone was a French mathematician who wrote a compendium of elementary mathematics written in French and Latin.
Mathematical Profile (Excerpt):
 Hérigone's only important work is the six volume Cursus mathematicus, nova, brevi, et clara methodo demonstratus Ⓣ(Course on mathematics : new, short, and with clear methods shown) or, to give it its French title, Cours mathematique, demonstre d'une nouvelle, briefve, et claire methode which appeared between 1634 and 1642.
 Hérigone did, however, introduce a number of familiar symbols such as ⟂ for 'is perpendicular to'.
 He also used < for 'angle' but since this is essentially the same as the 'less than' symbol, William Oughtred made a slight modification to Hérigone's notation using ∠ for 'angle' in Trigonometria (1657).
 At a time when an exponent notation was not in common use, Hérigone introduced a2,a3a2, a3a2,a3, etc for the powers of aaa.
 This is a variant of our present notation in which the powers are raised while in the form in which Hérigone used them they were on the same level as the aaa.
 To give a little flavour of this rather strange work, Hérigone describes a camera obscura in the form of a goblet which was designed so that one could spy on others at the table while drinking from the goblet.
 One of the problems which Hérigone looked at in the text concerns an apothecary who had four kinds of medicines, of which the first is hot in the fourth degree, the second is hot in the second degree, the third is cold in the first degree and the fourth is cold in the third degree.
 We know that Hérigone served on a number of committees and took a full part in the mathematical life of Paris.
 The committee members, in addition to Hérigone, were Étienne Pascal, Mydorge, Beaugrand, J C Boulenger and L de la Porte.
 Hérigone, and the rest of the committee, became involved in a dispute with JeanBaptiste Morin.
 We mentioned above that Hérigone also wrote under the name of Denis Henrion.
 As can be seen from the title, Hérigone added his own notes on the use of the compass of proportion.
Born 1580, France. Died 1643, Paris, France.
View full biography at MacTutor
Tags relevant for this person:
Analysis, Geography, Geometry
Thank you to the contributors under CC BYSA 4.0!
 Github:

 nonGithub:
 @JJO'Connor
 @EFRobertson
References
Adapted from other CC BYSA 4.0 Sources:
 O’Connor, John J; Robertson, Edmund F: MacTutor History of Mathematics Archive