117 



ROBESPIERRE, FRANCOIS-MAXIMILIEN. 



ROBESPIERRE, FRANCOIS-MAXIMILIEN. 



118 



The 'Method of Indivisibles,' which forms a link between the 

 ancient geometry and the fluxionary or differential calculus, had been 

 (1635) made public in Italy by Cavalleri, who is always considered as 

 its inventor. In a letter to Torricelli however (1644), Roberval states 

 that he himself had long before that time discovered a similar method 

 of investigating propositions ; and he adds, that he kept his processes to 

 himself, in order that he might have a superiority over his rivals in 

 solving such problems as were proposed to them. The statement may 

 be correct ; but if so, it happened that the French mathematician, by 

 his reserve, like many others in similar circumstances, lost the honour 

 which he might have obtained ; a just punishment, observes Montucla, 

 for those who, from such unworthy motives, make a mystery of their 

 discoveries. At the end of the treatise of Robervul on this subject, 

 there is explained a method of finding the areas of spaces com- 

 prehended between curve-lines of indefinite length, and it may be that 

 the credit of the discovery is due to him, though it is right to observe 

 that the investigation of such areas had been made in England by 

 James Gregory and Dr. Barrow before the publication of Roberval's 

 work. Curves with infinite branches, and which admit of an expres- 

 sion for the area between them, were called Robervallian lines by 

 Torricelli. 



Roberval discovered an ingenious method of determining the direction 

 of a tangent at any point of a curve-line by the rule for the composi- 

 tion of forces or motions; but he applied it only to the conic sections 

 in which the component forces are supposed to act in the directions 

 of lines drawn from the point in the curve to the foci. It appears 

 that Torricelli laid claim to the first discovery of the method, which 

 he asserts that he had made in 1644 ; but Roberval states, in a letter 

 to the Italian philosopher, that he was acquainted with it in 1636, and 

 that in 1640 he had communicated it to Fermat. 



As early as the year 1616, P. Mersenne suggested the idea of the 

 cycloid, and having made some fruitless attempts to find its area, he 

 proposed the subject to Roberval in 1628; the latter, not succeeding 

 immediately, abandoned the research, and apparently thought nothing 

 of it during about ten years. At the end of that time, the question 

 being revived, he resumed the inquiry with the advantage of greater 

 experience, and fortunately discovered a method by which the area 

 might be determined. Descartes afterwards proposed to Roberval 

 and Fermat to determine the position of a tangent to the cycloid, and 

 Fermat soon resolved the problem, but Roberval appears to have failed, 

 or to have succeeded with difficulty, and only after many trials. He 

 subsequently however discovered the rules for finding the volumes of 

 the solids formed by the revolution of a cycloid about its base and 

 about its axis. 



In 1646, Descartes, Roberval, and Huyghens attempted at the same 

 time to investigate the duration of the oscillations made by planes 

 and solids moving about an axis; and here Roberval appears to have 

 been more successful than his competitors, though the state of science 

 was not then sufficiently advanced to allow any of them to attain a 

 solution which should be applicable to every kind of vibrating body. 



None of Roberval's works were printed during his life, except a 

 treatise on Statics, which was inserted by Mersenne in his ' Harmouie 

 Uuiverselle.' The others were published by his friend the Abbe* 

 Galois, in 1693, among the mathematical and physical works in the 

 old 'Memoires' of the Academy of Sciences. These relate chiefly to 

 the subjects above mentioned, and include a treatise on the 'Recogni- 

 tion and Construction of Equation?,' a work of little utility, since it 

 is formed agreeably to the ideas of Descartes and Fermat, and is 

 expressed in the language and notation of Vieta. Among them also 

 is an account of a new kind of balance (a sort of steelyard) which 

 Roberval had invented, and which was thought to be useful in finding 

 the weight or pressure of the air. 



Roberval, unfortunately for his fame, appears among the opponents 

 of Descartes in matters relating to algebra : he is said to have made 

 some objections to the theorems of his countryman in the construction 

 of equations and concerning the nature of the roots ; but the objections 

 are without foundation, and serve only to expose his own jealousy and 

 obstinacy. 



To Roberval is ascribed the reply, " Qu'est ce que cela prouve 1 " 

 when, having been present at the representation of a tragedy, some 

 one asked what impression it had made on him. The story is perhaps 

 untrue; but such a circumstance is not improbable, since, in those 

 days, science was profoundly studied, and the mathematicians were so 

 completely absorbed in their pursuits, that they had little time to 

 spare for other subjects. It is said that Roberval could never express 

 his ideas with clearness and precision, and certainly readers well 

 acquainted with the ancient methods of investigation, can with diffi- 

 culty follow him in his tedious demonstrations. He was elected a 

 member of the Academy of Sciences when the latter was formed 

 (1665), and he died in the year 1675. 



ROBESPIERRE, FRANgOIS-MAXIMILIEN-JOSEPH-ISIDORE, 

 was born at Arras in 1759. His father, a provincial advocate of no 

 reputation, quitted France during the infancy of his children, who 

 were not long afterwards left in a desolate condition by the death of 

 their mother. Francois Maximilien was the eldest, and Augustin Bon 

 Joseph the second son ; the third child was a daughter. Augustin 

 imitated his brother, and perished with him ; the daughter lived in 

 quiet respectability, and became a pensioner of the state. 



Through the kindness of the bishop of Arras, Robespierre was well 

 educated at Paris. He studied jurisprudence ; and having returned to 

 his native town, followed his father's profession, in which he gained 

 some reputation. By his legal talents and his situation as president 

 of the academy at Arras, ho obtained an influence, through which, on 

 the summoning of the States-General in 1789, he was elected a deputy 

 of the tiers-<5tat. No sooner was he elected than he went to Ver- 

 sailles to enter on his duties. Within the Assembly, for several months 

 after its meeting, he was of little importance ; without its doors, he 

 gradually gained authority by gathering idlers and adventurers round 

 him in the coffee-houses, and haranguing them on liberty and equality. 

 It was by dexterity of address, and the coincidence or adaptation of 

 the opinions which he expressed, to those of his low, discontented, 

 and excited hearers, that this authority was raised. He had no 

 physical advantages to assist him : he was a short insignificant-looking 

 man ; his features were small, his complexion was pale, hia face deeply 

 marked with the small-pox, and his voice harsh, shrill, and disagreeable. 

 Notwithstanding these disadvantages, he increased in popular estima- 

 tion. It was on the 17th of June 1789, that he delivered his first 

 speech in the Assembly. From that time he daily threw aside more 

 and more of the backwardness and reserve that he had hitherto main- 

 tained : he clearly saw that the weakness and want of energy in the 

 government were so great, that he might with safety assert in the 

 National Assembly the most violent democratic opinions and throw 

 the populace into excitement. His importance in the Assembly was 

 in a great measure attributable to the prominent part which he played 

 in the Jacobin Club. This club already contained so many members, 

 that the large church in which its meetings were held, was continually 

 filled, and it had corresponding affiliated societies throughout the 

 provinces, which disseminated its revolutionary views and projects, 

 and rendered its power most formidable. Here was Robespierre's 

 principal scene of action ; here he decried every attribute of monarchy, 

 and denounced those who would control the people, as conspirators 

 against their country. Robespierre laid down this principle, that 

 " France must be revolutionised," and for this object he laboured with 

 a determination which his opponents could find no means of diminish- 

 ing. It was certain that he could not be tampered with ; and the 

 Jacobin newspapers, daily overflowing with his praises, surnamed him 

 " The Incorruptible." His exclusion from the Legislative Assembly, 

 to which he was rendered ineligible by a vote in which he himself had 

 joined, enabled him to devote his whole time and energies to the direc- 

 tion of the Jacobin Club. The violence of the club had somewhat 

 diminished, but its power was increased by the enrolment of many 

 of the municipal officers, who could carry out its projects by their 

 authority. At this time he was named Public Accuser. 



When the attack was made upon the Tuileries (Aug. 10, 1792), 

 Robespierre was not present; and for three days afterwards hefoisook 

 the club and remained in seclusion. It was his custom neither to take 

 an active part in the great overt acts of massacre or rebellion, nor to 

 appear immediately after their commission ; but rather to pause 

 a while, that he might see by what means they might best be turned to 

 the promotion of his political objects and the increase of his own 

 popularity. It was with joy that he saw the National Assembly 

 suspend the royal authority and call upon the nation to elect a con- 

 vention which should determine on a new form of government. He 

 became a member of the Convention ; and on its opening (Sept. 21, 

 1792), seated himself on the ' montagne,' or higher part of the room, 

 occupied by the most violent, which was also rapidly becoming the 

 most powerful party. It was now that Robespierre first appeared in 

 the foremost rank, which comprised the most powerful men : until 

 now, notwithstanding all his efforts, he had had superiors even in his 

 own party ; in the days of the Constituent Assembly, the well-known 

 leaders of the time ; during the continuance of the Legislative As- 

 sembly, Brissot and Pethion; and on the 10th of August, Danton. In 

 the first assembly he could attract notice only by the profession of 

 extravagant opinions ; during the second he became more moderate, 

 because his rivals were innovators ; and he maintained peace before 

 the Jacobins, because his rivals called for war. Now, as we have said, 

 he was in the first rank, and his chief aim was to annihilate the 

 Girondins, who hoped, on the other hand, that the eminence he had 

 attained was insecure as well as high, and that he might be overthrown 

 bimself. Barbaroux, Rebecqui, and Louvet dared to accuse him of 

 seeking to be dictator. But the time had not come for accusations to 

 be successful; the tide of his popularity had not turned. He demanded 

 time to prepare his defence, and absented himself for eight days both 

 from the Convention and the Jacobin Club. During this absence the 

 Jacobins protested his innocence and intimidated his accusers, the ex- 

 citement in the Convention subsided, and on his re-appearance he was 

 triumphantly exculpated. 



At this time the king was in prison, but his days were drawing to a 

 close. Robespierre vehemently combated those, who either asserted 

 bhe necessity of a trial or declared the king inviolable : he demanded 

 that he should be beheaded at once, and promoted unscrupulously the 

 execution of his whole family. The death of the king augmented both 

 party strife and private bitterness ; each faction and each leader had 

 some rival to destroy. The Montagnards struggled with the Girondins 

 For supremacy, gained their end, and massacred their opponents. The 

 kingdom was chiefly governed by the Committee of Public Safety, of 



