* LUBBOCK, SIR JOHN WILLIAM, BART., a distinguished mathematician and physical astronomer, the only child of the late Sir J. W. Lubbock, Bart., merchant and banker of London, was born on the 26th of March 1803, and succeeded to the title as third baronet on the demise of his father iu 1840. He was educated at Trinity College, Cambridge, where he graduated as M.A. in 1825. He was elected a Fellow of the Royal Society on the 15th of January 1829, and on the 30th of November of the following year was elected a member of the council and treasurer of the society. This officer, being also nominated, together with other members of the council, to the office of vice-president, appears by recent usage—which seems to have commenced with Sir J. W. Lubbock, under the presidency of his late Royal Highness the Duke of Sussex—to act as the senior vice president, in a more particular manner representing the president iu his absence in conducting the affairs of the society. He continued to be annually re-elected the treasurer till the year 1835, and subse quently from 1833 to 1845, thus having retained the office for twelve years, being a longer term than any of his predecessors during the present century. In the first charters, dated in 1837, of the University of Loudon, he is appointed one of the Fellows, and also the first vice chancellor, an office which he resigned iu 1842, retaining as a Follow his seat in the senate.
Sir John Lubbock is the author of numerous papers, chiefly relating to the principal subjects of science to which, in honourable union with the pursuits of commerce, he has devoted himself, in the ' Memoirs of the Royal Astronomical Society,' and in the Philosophical Trans actions of the Royal Society.' One of his earliest papers, ' On the Determination of the Orbit of a Comet,' was read before the former body on the 9th of January 1829, and is contained in the fourth volume of the 'Memoirs.' His first paper in the Philosophical Transactions' appears in the volume for 1830, under the title ' On the Pendulum,' and relates to the theory of the convertible form of that instrument, originally suggested in 1811 by Professor Bohueuherger of Tubingen, but which was first produced independently by the late Captain Kater. The author iu this paper, after noticing what had been done by Laplace and Whowell, attempts to discuss for the first time all the circumstances then known to affect the accuracy of Captain Kater's method, treating the question with the utmost gene rality, endeavouring to render the theory of the convertible pen dulum as perfect as the method of observation. But Sir John Lubbock's more considerable investigations have related to the Planetary aud Lunar theory, and to the Tides. His 'Researches in Physical Astronomy,' embracing the former subjects, were first pub lished in the Philosophical Transactions,' commencing with a paper in the volume for 1830, in which it is shown that the conditions relative to the disturbing forces under which Laplace had demon strated that the stability of the planetary system is always eventually preserved, are not necessary to the stability of a system of bodies subject to the law of attraction which governs our system ; but that the variations of the elliptic constants are all periodic, and "oscillate therefore within certain limits. This theorem is no longer true if the planet moves in a resisting medium." The second paper in the same volume consists of two parts—' On the Precession of the Equinoxes,' and ' On the Theory of the Motion of the Planets,' in continuation. In the first part the author extends his former conclusions regarding the stability of the system to the problem of the Precession of the Equinoxes, understanding that stability to mean, iu this ease, "that the pole of the axis of rotation has always nearly the same geographical latitude, and that the angular velocity of rotation and the obliquity of the ecliptic vary within small limits, and that its variation is periodical." These researches are pursued ha nine other elaborate papers eon brined In the 'Philosophical Transactions' for 1831, 1832, 1834, and 1 S 35 . Nearly the whole Investigation was subsequently published as a separate work, under the title, ' On the Theory of the Moon and on the Perturbations of the Planets,' which first appeared in 1833; a new editiou, occasioned by some researches of Plana, being published in parts in the three following years. An account of the ' Traitd sur le Flux et Rtiflux do la Met' of Daniel Bernoulli, in a separate tract (London, 1830), preceded the publication of Sir J. W. Lubbock's investigations on the Tides, principally as they occur in the ports of London and Liverpool, which were communicated to the Royal Society from 1831 to 1837, in nine papers ; the Bskerian Lecture for 1836 being one of those ' Oia the Tides at the Port of London.' The Royal
Medal on Physics for 1834 had been awarded to him by the Council of the Royal Society, for his "highly valuable investigations on the tides," which down to that period had been published in the 'Transactions.' In the Phil. Trans.' for 1831 and 1841 are two papers on the subject of meteorology, which conclude the list of the author's contributions to the Royal Society. On that science, as well as on the tides, ho also contributed some papers to the ' Companion to the British Almanac; and this leads us to notice that he was an original member of the Committee of the Society for the Diffusion of Useful Knowledge, and edited the ' Maps of the Stars,' which formed part of the publications issued under its superintendence. In conformity with the practice of other mathematicians and physical astronomers of all periods, in addition to papers contributed to academical collections, he has made public some of his results and views in separate tracts. Among the subjects of these are Cask-gaging,' the ' Computation of Eclipses and Occultations,' the ' Classification of the Differeut Branches of Human Knowledge' (of which two editions havo appeared), an 'Elementary Treatise on the Tides,' 1839, and an elaborate investigation On the Heat of Vapours and on Astronomical Refractions,' bearing on many important objects of meteorological and chemical research, as well as on astronomy. Some of these tracts, or their substance, are inserted also in the ' Philosophical Magazine.' The improvement of mathematical notation appears to have been an object held in view by Sir John Lubbock, from an early period in his mathematical researches. In 1829 he communicated a paper 'On Notation' to tho Astronomical Society, which was inserted iu the Memoirs,' vol. ix., p. 471. After remarking that that part of the theory of mathematical notation which relates to symbols of quantity had hitherto been entirely disregarded, slid briefly adverting to that theory as regards language, he proceeds to submit his own rules of notation, and a table exhibiting synoptically that employed by some of the most distinguished astronomers for a few of the quantities which occur frequently. The subject is returned to repeatedly in his subse quent works, in one of which (the preface to the account of 'Bernoulli on the Tides' already noticed) he observes, "It is, 1 think, a matter of great regret, that the notation adopted by different mathematicians should be so various. I have therefore thought it desirable to give frequent comparisons of the symbols I have adopted with those to be found elsewhere ; and I have endeavoured as far as possible not to use the same letter for different quantities, and not to represent the same quantity by different letters." A notice of one of those subjects of profound interest which unite the objects of the astronomer with those of the geologist, suggested by our author, must conclude this article. His first paper on the 'Precession of the Equinoxes,' 1833, as already alluded to, proceeded upon the hypothesis that the earth revolves in a medium devoid of resistance. In the 'Phil. Trans.' of the following year he investigates the subject on the supposition that the earth revolves in a resisting medium, the effect of the resistance of which "is to increase the latitude of the axis of rotation (reckoned from the equator of the figure), till It reaches 90°. Such is now the condition of the axis of the earth; but as the chances are infinitely great against this having been its original position, may not its attainment of this position be ascribed to the resistance of a medium of small density acting for a great length of time,—a supposition which may account for many geological indications of changes having taken place in the climates of the earth 1" This suegeetion of a possible cause of many geological phenomena, certaiuly of the nature of a 'very cause,' appears, most unaccountably— except indeed that it had been offered in researches on physical astronomy—to have been left unnoticed by geologists, until the author himself revived it, eighteen years after its first enunciation, in a letter to Sir C. Lyell, read before the Geological Society in 1348, and published in its 'Quarterly Journal,' vol. v., p. 4. In this letter the subject is pursued, explicitly, into several of its geological conse quences; and Sir J. Lubbock'e views were discussed in some detail, by the then president, Sir II. T. De La Beebe, in his anniversary address of 1849, inserted in the same volume of the 'Journal,' pp. lxxxv.-1xxxix.