06 



CHARNOCK, STEPHEN. 



CHASTELLET, MARQUISE DU. 



208 



Paris, 1736; this work is taken almost entirely from Kiimpfer ; 

 2, 'History of St. Domingo,' 2 vols. 4to, Paris, 1730; 3, 'History of 

 New France,' 3 vols. 4to, Paris, 1744, which contains a good account 

 of the French establishments in Canada and North America ; (part of 

 this work, including his own travels in those countries, was translated 

 into English in 1760, under the title of ' Journal of a Voyage to North 

 America;') 4, 'History of Paraguay,' 3 vols. 4 to, Paris, 1756; which 

 was translated into English in 1769. 



The thick quartos of Charlevoix are a compound of travels and 

 history, not very skilfully mixed ; but although he had neither the 

 order and philosophy necessary to an historian, nor the enterprise 

 and vivacity of a traveller, he waa a very industrious man, and col- 

 lected many things which still render his books valuable for occasional 

 reference. 



CHARNOCK, STEPHEN, a nonconformist, was known in his 

 lifetime as an active and eloquent theologian, and is now remembered 

 for the merit of writings not published till after his death. He was 

 born in London, in 1628. At one time he was senior proctor in the 

 University of Oxford ; and afterwards he became a preacher in Dublin. 

 Being ejected thence by the Act of Uniformity, he held for fifteen 

 years the charge of a dissenting congregation in London, where he died 

 in 1 680. His printed works are the following : ' Several Discourses 

 of the Existence and Attributes of God,' 1682, foL ; ' Works,' 1684, 

 2 vols. fol. ; ' Two Discourses, of Man's Enmity to God ; and of the 

 Salvation of Sinners,' 1699, 8vo. 



CHARON, a native of Lampsacus, on the Hellespont, one of those 

 numerous Greek historical writers now only known by their names 

 and a few fragments. Charon lived before Herodotus, who was born 

 B.C. 464, and he was younger than Hecatseus, who was probably in the 

 vigour of his life about B.C. 500. Charon wrote a history of his native 

 town, a bUtory of Persia, a history of Crete, and other works. The 

 loss of the Cretan history is to be regretted, as we possess so few 

 materials for the ancient state of that island. 



(Suidis, Xdftav ; Creuzer, flwtoricorum Gfrcecorum Antiquiu. Frag- 

 mcnta, <fcc., Heidelberg, 8vo, 1806.) 



Suidas mentions two other writers of the name ; one of Carthage, 

 and the other of Naucratis, in Egypt. 



* CHASLES, MICHEL, an eminent geometer, was born at Epernon 

 (Eure-et-Loire) 15th of November 1793. In 1812 he entered the 

 Koole Polytechnique, where his researches on the theory of surfaces of 

 the second order, to which he at once devoted himself, soon brought 

 him into notice. They are published in the ' Correspondence sur 

 I'ficole Polytechnique' for 1813 and 1815. Before then there was no 

 other proof of the double generation of the hyperboloid of one sheet 

 than the analytical demonstration by Monge ; Chasles produced one 

 purely geometrical, which was immediately adopted in the instructions 

 of the school. By another class of researches he established different 

 theorems, which were used by Poncelet in his ' Traitc des proprie'tcs 

 projectives des Figures' (4to, Paris, 1822). In a later series of memoirs 

 he teaches how infinitely thin laminae may be constructed, partaking 

 of the properties of electric films formed on the surfaces of conducting 

 bodies, by methods which give him a distinguished place among 

 analysts. But it is in pure geometry that his power of generalisation 

 it best seen : he at once extends and simplifies the most important 

 theories. 



The Academy of Sciences at Brussels having proposed as a prize 

 question, "On demande un examen philoaophique des diffu'rentes 

 me'thodes employees dans la ge'onie'trie re'cente, et particulierement de 

 la mfcthode des polaires reciproques,' M. Chasles answered it by an 

 elaborate paper which was crowned by the Academy in 1830, and 

 published in the llth volume of their ' Mc'moires.' It was considerably 

 amplified and reprinted by the author in 1837, under the title 'Apercu 

 historique sur 1'origine et le deVeloppementdes me'thodes en gc'ome'trie, 

 particulierement de celles qui se rapportent a la geometric moderne, 

 suivi d'un me'moire sur deux priucipes ge'ne'raux de la science, la 

 dualit^ et 1'homographie,' 4to, Paris. This work is not merely a 

 learned history of different geometrical methods ; in the thirty-four 

 notes which accompany it M. Chasles approaches important questions; 

 giving a large extension to the theory of the involution of six points 

 which originates in one of Desargues' theorems, and establishing the basis 

 of a new theory of conic sections and of surfaces of the second order. 



Many questions in pure geometry could only be resolved by a com- 

 plicated process which rendered their solution exceedingly difficult if 

 not impossible, notwithstanding the researches of Carnot and other 

 mathematicians. M. Chasles however by an ingenious algorithm suc- 

 ceeded in introducing the principle of signs into pure geometry, and 

 showed moreover that imaginaries might be brought into consideration 

 without difficulty. He has thus created a new branch of mathematics, 

 characterised by the uniformity of the method. Its merits consist in 

 the ability which it gives of deducing immediately from one single 

 principle all those admirable properties of conic sections known as 

 theorems of Pappus, Desargues, Pascal, Newton, Brianchon, and 

 others; and also that it establishes a multitude of new ones by the aid 

 of this principle, and of a certain law of correlation. 



In 1841 M. Chasles was appointed professor of astronomy and of 

 applied mechanics at the fccole Polytechnique. It wag felt that his 

 brilliant discoveries called for a chair specially devoted to that course 

 of teaching, and in 1846 the chair of higher geometry was instituted 



at the Faculty of Sciences. Entered on his duties in this new post, 

 M. Chasles co-ordinated the elements of the science, and published the 

 first portion in his ' Traite* de Ge'ome'trie Superieure,' 8vo, Paris, 1852. 

 The method applies equally to conic sections and lines of the higher 

 orders, as the author has demonstrated in various memoirs which are 

 to form the groundwork of succeeding volumes. 



By his historical researches M. Chasles has promoted science in 

 another way. His 'Aper9u historique' contains new ideas on the 

 signification of the porisms of Euclid, and an explanation of the 

 geometrical part of the works of the Hindoos, which bear evidence of 

 profound erudition. In the same work, and in his ' Histoire de 

 1'Arithmdtique' (4to, 1843), he shews proof that our system of nume- 

 ration ia of Pythagorean origin and not Arabian, as is commonly 

 believed. Others of his writings are to be found in the 'Journal 

 de 1'Kcole Polytechnique,' Gergonue's 'Annales de Mathe'matiques,' 

 Quetelet's ' Correspondence Mathe'matlque et Physique,' Liouville's 

 ' Journal de Mathe'matiques,' ' Comptes Rendus de 1'Acad. des Sciences,' 

 ' Connaissance des Temps,' &c. 



M. Chasles was elected a member of the Academy of Sciences in 

 1851, the same year that he commenced his lectures at the Faculty of 

 Sciences. In 1854 he was chosen a foreign member of the Royal Society 

 of London. 



CHASSfi, DAVID HENRY, BARON, the resolute defender of 

 Antwerp, was born at Thiel, in Gueldre, March 18, 1765. In 1775, 

 he entered the Dutch army as a cadet, but he left that service after 

 the revolution in Holland in 1787, and attached himself to the French 

 army, hi which he continued for many years. He became a lieutenant- 

 colonel in 1793. In the fierce war with Prussia in 1806, he greatly 

 distinguished himself under the Dutch general Dumorceau, and was 

 made general of brigade. He afterwards took part in the Peninsular 

 War, and displayed so much intrepidity that the soldiers nicknamed 

 him 'General Bayonet,' from his constant use of that weapon. In 

 1811, Napoleon created him a baron of the empire. He was frequently 

 wounded, and during the campaigns of 1813 and 1814 he had several 

 horses killed under him. He fought likewise at Waterloo. Soon after 

 the peace he was made governor of Antwerp, and his admirable 

 defence of the citadel in 1832, with a garrison of 6,000 troops, against 

 an army of 75,000 French soldiers commanded by Marshal Ger.ird, 

 attracted general attention throughout Europe, and made the bravo 

 old soldier very popular. He died on the 2nd of May 1849. (Biogr . 

 da Contemporains ; Campo, Life of Chassi.) 



CHASTELLET, GABRIELLE-fcMILIE LE TONNELIER DE 

 BRETEUIL, MARQUISE DU, the translator of Newton into French, 

 was the daughter of Baron de Breteuil, and was born in 1706. In 

 what manner she was led to study mathematics is not stated; she 

 also became a proficient in Latin, English (in which Voltaire, as he 

 tells us, was her instructor), and Italian. She was married very early 

 to the Marquis du Chastellet-Lomont, a lieutenant-general of a dis- 

 tinguished family of Lorraine. In 1733 she retired to the castle of 

 Cirey, on the borders of Champagne and Lorraine, where she pursued 

 her studies for several years. She died August 10, 1749, her death 

 having been hastened by close application to her translation of 

 Newton. She died in the palace of Luneville, at the court of Stanislas, 

 where her husband filled the office of high steward, and where Voltaire 

 also was then residing. Her liaison (as the French call it) with 

 Voltaire furnished sundry anecdotes for the scandalous chronicles of 

 her day. The state of manners however, and in particular the light 

 in which the marriage contract was regarded among the French, are 

 too well known to require any comment. 



In 1738 Madame du Chastellet wrote, for the prize of the Academy 

 of Sciences, on the nature of fire. In 1740 she published at Paris 

 her ' Institutions de Physique,' addressBd to her son, and a second 

 edition appeared at Amsterdam in 1742. This work is a series of 

 letters, in which the systems of Leibnitz and of Newton (the latter 

 then almost new in France) are explained in a familiar style, and with 

 a degree of knowledge of the history of the several opinions, and of 

 sound language and ideas in their discussion, which we read with 

 surprise, remembering that they were the production of a French- 

 woman thirty years of age, written very few years after the introduction 

 of the Newtonian philosophy into France. She takes that inter- 

 mediate view between the refusal to admit the hypothesis of attraction, 

 and the assertion of it as a primary quality of matter, from which 

 very few who consider the subject would now dissent. At the end 

 of this work is an epistolary discussion with M. de Mairan, on the 

 principle of "vis viva," the metaphysical port of which then created 

 much controversy. 



The translation of Newton was published at Paris in 1759, with a 

 " preface historique," and an dloge in verse by Voltaire, who probably 

 owed to Madame du Chastellet the smattering of knowledge upon 

 which he wrote his ' Elemens de la Philosophie de Newton,' published 

 in 1738. From it we learn that the translation was submitted to the 

 revision of Clairaut, who was the instructor of the authoress in 

 mathematics. To the work is added a commentary, which bears the 

 name of Clairaut, being in fact his lessons committed to writing and 

 arranged by Madame du Chastellet, and afterwards revised by their 

 author. We here find, 1, a popular account of Newton's system ; 2, 

 investigations of various points by the analysis of the continental 

 school, to the exclusion of the geometry of Newton ; 3, an abndg- 



