Lagrange in using both these notations), but because it signified the opening to the mathematicians of Cambridge of the vast storehouse of continental discoveries.
In preparation for these he spent the winter of 1877-1878 in reading up original treatises like those of Laplace and Lagrange on mathematics and mechanics, and in attending courses on practical physics under P. G.
The Wilcox formation (called Lignitic by Hilgard, and named by Safford the Lagrange group) lies to the west of the last, and its western limit is from about 32° 12' on the Alabama boundary about due north-west; in its north-westernmost part it is on the western edge of the Tertiary in this state.
Of this school, which had Lagrange for its professor of mathematics, we have an amusing account in the life of Gilbert Elliot, 1st earl of Minto, who with his brother Hugh, afterwards British minister at Berlin, there made the acquaintance of Mirabeau.
Pp. 420 sqq.; Lagrange, Etudes d.
Lagrange, Etudes d.
The 18th century witnessed a rapid development of analysis, and the period culminated with the genius of Lagrange and Laplace.
As far back as 1 773 Joseph Louis Lagrange, and later Carl Friedrich Gauss, had met with simple cases of such functions, George Boole, in 1841 (Camb.
DaP4 References For Symmetric Functions.-Albert Girard, In- -vention nouvelle en l'algebre (Amsterdam, 1629); Thomas Waring, Meditationes Algebraicae (London, 1782); Lagrange, de l'acad.
1901) frankly describes the condition of ecclesiastical biblical studies; Monseigneur Mignot, archbishop of Albi, Lettres sur les etudes ecclesiastiques 1900-1901 (collected ed., Paris, 1908) and "Critique et tradition" in Le Correspondant (Paris, Toth January 1904), the utterances of a finely trained judgment; Mgr Le Camus, bishop of La Rochelle, Fausse Exegese, mauvaise theologie (Paris, 1902), a timid, mostly rhetorical, scholar's protest; Pere Lagrange, a Dominican who has done much for the spread of Old Testament criticism, La Methode historique, surtout a propos de l'Ancien Testament (Paris, 1903) and Eclaircissement to same (ibid.
1903); P. Lagrange, Mgr P. Batiffol, P. Portalie, S.
JOSEPH LOUIS LAGRANGE (1736-1813), French mathematician, was born at Turin, on the 25th of January 1736.
His father, Joseph Louis Lagrange, married Maria Theresa Gros, only daughter of a rich physician at Cambiano, and had by her eleven children, of whom only the eldest (the subject of this notice) and the youngest survived infancy.
The genius of Lagrange did not at once take its true bent.
The first volume of its memoirs,' published in the following year, contained a paper by Lagrange entitled Recherches sur la nature et la propagation du son, in which the power of his analysis and his address in its application were equally conspicuous.
By these performances Lagrange found himself, at the age of twenty-six, on the summit of European fame.
The prize was again awarded to Lagrange; and he earned the same distinction with essays on the problem of three bodies in 1772, on the secular equation of the moon in 1774, and in 1778 on the theory of cometary perturbations.
The post of director of the mathematical department of the Berlin Academy (of which he had been a member since 1759) becoming vacant by the removal of Euler to St Petersburg, the latter and d'Alembert united to recommend Lagrange as his successor.
On the 6th of November 1766, Lagrange was installed in his new position, with a salary of 6000 francs, ample leisure for scientific research, and royal favour sufficient to secure him respect without exciting envy.
Soon after marriage his wife was attacked by a lingering illness, to which she succumbed, Lagrange devoting all his time, and a considerable store of medical knowledge, to her care.
The long series of memoirs - some of them complete treatises of great moment in the history of science - communicated by Lagrange to the Berlin Academy between the years 1767 and 1787 were not the only fruits of his exile.
2 From the fundamental principle of virtual velocities, which thus acquired a new significance, Lagrange deduced, with the aid of the calculus of variations, the whole system of mechanical truths, by processes so elegant, lucid and harmonious as to constitute, in Sir William Hamilton's words, "a kind of scientific poem."
But before that time Lagrange himself was on the spot.
Der Mechanik, 220, 367; Lagrange, Mec. An.
Even from revolutionary tribunals, however, the name of Lagrange uniformly commanded respect.
Meanwhile, on the 31st of May 1792 he married Mademoiselle Lemonnier, daughter of the astronomer of that name, a young and beautiful girl, whose devotion ignored disparity of years, and formed the one tie with life which Lagrange found it hard to break.
The former institution had an ephemeral existence; but amongst the benefits derived from the foundation of the Ecole Polytechnique one of the greatest, it has been observed, 4 was the restoration of Lagrange to mathematics.
By means of this "calculus of derived functions" Lagrange hoped to give to the solution of all analytical problems the utmost "rigour of the demonstrations of the ancients"; 6 but it cannot be said that the attempt was successful.
Delambre, Ouvres de Lagrange, i.
On the establishment of the Institute, Lagrange was placed at the head of the section of geometry; he was one of the first members of the Bureau des Longitudes; and his name appeared in 1791 on the list of foreign members of the Royal Society.
Amongst the brilliant group of mathematicians whose magnanimous rivalry contributed to accomplish the task of generalization and deduction reserved for the 18th century, Lagrange occupies an eminent place.
This is especially the case between Lagrange and Euler on the one side, and between Lagrange and Laplace on the other.
The calculus of variations lay undeveloped in Euler's mode of treating isoperimetrical problems. The fruitful method, again, of the variation of elements was introduced by Euler, but adopted and perfected by Lagrange, who first recognized its supreme importance to the analytical investigation of the planetary movements.
Finally, of the grand series of researches by which the stability of the solar system was ascertained, the glory must be almost equally divided between Lagrange and Laplace.
Laplace owned that he had despaired of effecting the integration of the differential equations relative to secular inequalities until Lagrange showed him the way.
Lagrange saw in the problems of nature so many occasions for analytical triumphs; Laplace regarded analytical triumphs as the means of solving the problems of nature.
Poisson in a paper read on the 10th of June 1808, was once more attacked by Lagrange with all his pristine vigour and fertility of invention.
He had not attempted to include in his calculations the orbital variations of the disturbing bodies; but Lagrange, by the happy artifice of transferring the origin of coordinates from the centre of the sun to the centre of gravity of the sun and planets, obtained a simplification of the formulae, by which the same analysis was rendered equally applicable to each of the planets severally.
It deserves to be recorded as one of the numerous coincidences of discovery that Laplace, on being made acquainted by Lagrange with his new method, produced analogous expressions, to which his independent researches had led him.
The final achievement of Lagrange in this direction was the extension of the method of the variation of arbitrary constants, successfully used by him in the investigation of periodical as well as of secular inequalities, to any system whatever of mutually interacting bodies.'
He proposed to apply the same principles to the calculation of the disturbances produced in the rotation of the planets by external action on their equatorial protuberances, but was anticipated by Poisson, who gave formulae for the variation of the elements of rotation strictly corresponding with those found by Lagrange for the variation of the elements of revolution.
In the advancement of almost every branch of pure mathematics Lagrange took a conspicuous part.
To Lagrange, perhaps more than to any other, the theory of differential equations is indebted for its position as a science, rather than a collection of ingenious artifices for the solution of particular problems. To the calculus of finite differences he contributed the beautiful formula of interpolation which bears his name; although substantially the same result seems to have been previously obtained by Euler.
Besides this most important contribution to the general fabric of dynamical science, we owe to Lagrange several minor theorems of great elegance, - among which may be mentioned his theorem that the kinetic energy imparted by given impulses to a material system under given constraints is a maximum.
In the Berlin Memoirs for 1778 and 1783 Lagrange gave the first direct and theoretically perfect method of determining cometary orbits.
3 As a mathematical writer Lagrange has perhaps never been surpassed.
Ouvres de Lagrange, publiees sous les soins de M.
Francois Joseph Lagrange-Chancel >>