John, a distinguished professor of natural philosophy, born in 1739 at Boghall, in the parish of Balnecock and county of Stirling; was a younger son of John Robison, Esq., who had formerly been a merchant at Glasgow, and had retired to live in considerable affluence on his estate at Boghall, not far from that city.

He was of a family sufficiently respectable to enable his son at a subsequent period to prove himself, to the satisfaction of the court of St Petersburg, a gentleman born. As a younger brother, that son was originally intended for the church, and went at an early age, according to the custom of Scotland, in 1750, to enter as a student in the university of Glasgow, so that he was initiated almost in the rudiments of Grecian literature under the able instruction of Dr Moor, the well-known professor of Greek; and he acquired such a knowledge of the classical languages as served to constitute him a correct scholar through life. He pursued his studies with so much attention as to obtain the approbation of his teachers and the admiration of his contemporaries, who were delighted with the originality and ingenuity of his conversation, though he did not himself reflect with perfect satisfaction upon the degree of application which he had exerted in his academical education. He took the degree of Master of Arts in 1756, having studied mathematics under Dr Robert Simson, and moral philosophy under Dr Adam Smith. The example of so correct and rigid a follower of the ancient methods of demonstration as Dr Simson, must unquestionably have exercised considerable influence on his yet unformed taste in mathematics; but he seems to have had a natural preference, either from the constitution of his mind, or from some previously acquired habits of thinking, for the geometrical method; for we are informed that "he first attracted the regard of Dr Simson by owning his dislike of algebra, and by returning a neat geometrical solution of a problem which had been given out to the class in an algebraical form: with this mode of solution the professor was delighted, though the pupil candidly acknowledged that it had been adopted only because he could not solve the problem in the manner required of the class."

In the course of his studies, he had imbibed an insuperable aversion to the pursuit of his original objects in the church; not certainly from any want of religious feeling, or from a dislike to the kind of life that was intended for him, but probably from some difficulties that had occurred to him respecting particular points of doctrine or of practice. He was therefore compelled to provide himself with some other occupation; and he readily accepted the offer of some of his friends in 1758, to recommend him to Dr Blair, a prebendary of Westminster, who had formed a scheme for sending Prince Edward, the young duke of York, to complete his professional education at sea, in com- pany with a son of Admiral Knowles; and Mr Robison was to have instructed his royal highness in mathematics and navigation. On his arrival in London, he was much disappointed to find that the expedition had never been seriously intended; and he readily accepted an engagement to attend young Knowles as a private tutor, when he went as a midshipman on board of the Neptune of ninety guns, with Admiral Saunders, who had the command of a force intended to co-operate with General Wolfe in the reduction of Quebec; and upon the appointment of his friend as a lieutenant on board of the Royal William, Robison was himself rated as a midshipman in that ship.

The fleet arrived on the coast of America in April 1759; in May they got up the river, and Mr Robison was one of a party of 100 seamen draughted from the Royal William into the admiral's ship, under the command of Lieutenant Knowles. In this capacity he had an opportunity of seeing considerable service, and of making some surveys of the river and of the neighbouring country; an employment for which he was perfectly qualified, both as a geometrician and a draughtsman. He also remarked the effect of the aurora borealis on the compass, which had been noticed by Mairan and Wargentin some years before, but which was then not commonly known. After the battle which was signalized by the victory and death of the gallant Wolfe, the Royal William sailed with his body to Europe, and arrived at Spithead in November. The next year she was sent to cruise off Cape Finisterre; but in six months she was obliged to return home, from having the greater part of the men disabled by the scurvy.

He used to consider the two years that he spent on board of the Royal William as the happiest of his life; and no considerable part of his gratification was derived from the study of seamanship as he saw it practised under the auspices of Captain Hugh Pigot. He did not, however, acquire any firm attachment to the mode of life which he had temporarily adopted; he was rather disposed to resume his academical pursuits, and he had overcome his earlier objections to the ecclesiastical profession. He could not, however, refuse the kindly invitation of Admiral Knowles to come and live with him in the country, and to assist him in some important experiments which he was making upon mechanical and nautical subjects.

In the month of February 1762, Lieutenant Knowles was appointed to the Peregrine sloop, of twenty guns, and Mr Robison accompanied him with the hope of becoming a purser. He visited Lisbon and several other parts of Portugal; but he found a cruise in a small ship much less convenient and agreeable than in a large one; and, fortunately for himself and for mankind, he finally quitted the Peregrine and the naval service in June, and returned to live with Admiral Knowles, who soon after recommended him as a proper person to take charge of Harrison's timekeeper, which had been completed by the labour of thirty-five years, after many unsuccessful experiments, and which was now sent out by desire of the Board of Longitude to the West Indies, under the care of young Harrison and of Mr Robison. The rate of the chronometer was ascertained at Portsmouth the 6th November 1762, and it indicated at Port Royal, in Jamaica, a difference of time amounting to $5^{\circ} 2^{\prime\prime} 47^{\prime\prime}$, which is only four seconds less than the true longitude. After a few days the observers had a prompt opportunity of returning home by the Merlin sloop, which was sent to Europe with despatches. The voyage was most disastrous with respect to wind and weather, and at last the ship took fire; but she arrived safe at Portsmouth in March, and on the 3rd of April the watch gave $11^{\text{h}} 58^{\text{m}} 63^{\text{s}}$, instead of $12^{\text{h}}$, for the time of mean noon, so that the error, after six months, was only $1^{\text{h}} 53^{\text{m}} 43^{\text{s}}$, amounting to no more than about twenty miles of distance.

Mr Robison received, upon his return, the afflicting intelligence of the total loss of the Peregrine, which had founded at sea with her commander and the whole of the ship's company. He was also greatly disappointed in the failure of some hopes which had been held out to him from the Admiralty and the Board of Longitude; though in fact there is little reason for the public to regret that he was not gratified with the pursership, which he claimed as the reward of his services. He was indeed afterwards actually made a purser by Lord Sandwich, in 1763; but he then declined accepting the appointment. His biographers very naturally complain of the neglect of those boards which ought to have recompensed him; but certainly the Board of Longitude had no power whatever, and probably not much influence, in the appointment of a purser; and, after all, the delay of a year or two was nothing very uncommon in the navy.

He had now no other resource than to return to Glasgow, and to resume his academical pursuits with renewed energy. It was from this time that he dated his serious application to his studies. He became extremely intimate with Dr Reid and Dr Alexander Wilson; and he had the advantage of being a witness of two of the greatest steps in the improvement of physical science that have been made in modern times, Dr Black's experimental theory of heat, and Mr Watt's invention of a new steam-engine. Dr Black was the first that determined the quantity of heat required for the conversion of ice into water: Mr Watt, who was settled as a mathematical instrument-maker at Glasgow, had been employed in repairing a working model of Newcomen's engine for one of the professors of the university; and it was the difficulty of supplying this model with steam that suggested to Mr Watt the eligibility of having a separate condenser, and that led him, in conjunction with Dr Black, to a knowledge of the quantity of heat consumed in evaporation.

Amid the enthusiasm which is always inspired by the progress of scientific discovery and of practical improvement, Mr Robison found every encouragement and every facility for the pursuit of his favourite objects. He was recommended by Dr Black, upon his removal to Edinburgh in 1766, as his successor in the lectureship of chemistry, though without the appointment of a professor. He took charge, also, of the education of Mr Macdowall of Garthland, and of Mr Charles Knowles, afterwards Sir Charles. Admiral Knowles was soon after recommended by the British government to the empress of Russia, in order to effect a reformation in her navy, having been employed on a similar service in Portugal almost fifty years before; he had always been a firm friend to Mr Robison, and now engaged him on this mission, with a salary of L250 a year; and they proceeded together to St Petersburg in December 1770. Being hospitably entertained on their way by the prince bishop of Liege, whom they found to constitute, with his chapter and all his servants, a lodge of freemasons, Mr Robison was easily persuaded to become one of that fraternity: in a few days he was made an apprentice, and by degrees attained the rank of Scottish master, as he has himself related in his publication upon the subject. He continued nearly two years at St Petersburg, still acting in the capacity of private secretary to Sir Charles, who was appointed president of the Board of Admiralty, much to the advantage of the Russian navy, though his improvements were frequently retarded by the prejudices of the native officers. Mr Robison was then appointed inspector general of the corps of marine cadets at Cronstadt, with a double salary, and with the rank of lieutenant-colonel. His duty was to receive the report of about forty teachers and professors, respecting the studies of 400 young noblemen, who were their pupils, and to class them according to his judgment of their merits; but he had himself nothing to teach, nor could he have had much occasion for "lecturing fluently..." in the Russian language," though he was introduced by his friend Kutusoff to the Grand Duke Paul as a proficient in that language; but to the empress he was not personally known. At Petersburg he could have lived without regretting his country, in the society of such men as Euler and Alpinus, admired by the Russians, and beloved by the British; but Cronstadt in winter was deplorably melancholy; and in 1773 he was induced, without much difficulty, to make some little pecuniary sacrifice in accepting the professorship of natural philosophy at Edinburgh, which had become vacant by the death of Dr Russell, and to which he had been recommended by Dr Robertson, then principal of the university. His determination was not disapproved by the Russian government, who granted him a pension of about L80 a year for life; but it was only paid as long as three or four young men, who had accompanied him as pupils, continued to reside at Edinburgh; some discontent having been expressed because he did not keep up a correspondence with the academy on the improvement of maritime education.

He arrived at Edinburgh in September 1774. He married soon afterwards, and continued to reside in that city for the remaining thirty years of his life, paying only an annual visit to his native place, where he possessed a part of the paternal estate; not being solicitous to extend it, although "he did not diminish it otherwise than as it had been diminished before," that is, in making provision for younger children. His predecessor had been very judicious and successful as a lecturer, though not a mathematician of the highest order: he had himself more practical knowledge and experience in mechanics, and was better acquainted with the foreign mathematicians, who had naturally fallen under his notice during his residence on the continent. His lectures were considered by most of his pupils as somewhat too difficult to be followed; a complaint which, if it did not depend on their own want of preparatory information, arose perhaps rather more from the hasty manner of his enunciation than from the abstruseness of his matter. "The singular facility of his own apprehension," says Professor Playfair, "made him judge too favourably of the same power in others. To understand his lectures completely was, on account of the rapidity and the uniform flow of his discourse, not a very easy task, even for men tolerably familiar with the subject. On this account his lectures were less popular than might have been expected from such a combination of talents as the author of them possessed." This inconvenience was increased by the small number of experiments he introduced, and a view that he took of natural philosophy, which left but a very subordinate place for them to occupy. An experiment, he would very truly observe, does not establish a general proposition, and never can do more than prove a particular fact;" but he seems to have carried this principle to some little excess: it is, in fact, the illustration, and not the proof, of general principles that is the object of a public exhibition of experiments; and it is very doubtful whether Archimedes, or Newton, or Leibnitz, or Euler, would have been very successful as showmen. With respect, however, to "accuracy of definition, to clearness, brevity, and elegance of demonstration, and even to neatness and precision in experiments," Professor Robison was very successful; his course extended "to every branch of physics and of mixed mathematics," and entered so fully into the detail of each particular division of the subjects, that "a more perfect system of academical instruction is not easily to be imagined." Nothing, in short, was wanting, but so much previous knowledge of mathematics in his pupils as he thought he had a right to expect, though his expectations were too rarely fulfilled.

The Philosophical Society of Edinburgh had almost been suffered to sink into oblivion after the publication of the third volume of its Essays, in 1756. Professor Robison became a member of it soon after his return from Russia, and was chosen secretary of the new society upon its formation by royal charter in 1783, when it incorporated with itself the whole of the surviving members of the former society. In 1798 he received the compliment of a degree of Doctor of Laws from the university of New Jersey; and a similar honour was paid him at Glasgow the year after. In 1800 he was elected, as successor to Dr Black, on the list of the foreign members of the Royal Academy of Sciences of St Petersburg.

In 1785 he was attacked by a severe disorder, from which he was never afterwards wholly free, though it produced little inconvenience besides pain, with some depression of spirits, which was, however, attributed rather to the closeness of his application than to the immediate effect of the disease, which was a glandular induration. For many years he was obliged to obtain the assistance of substitutes in the delivery of his lectures; but towards the end of his life he was able again to perform the duties of the professorship in person. He continued his literary labours with little intermission, and was most happy in the care and attention of his wife and children, whose virtues he found the best alleviation of his sufferings. He took a slight cold, after giving a lecture, on the 28th of January 1805, and died on the 30th.

1. It was comparatively late in life that Professor Robison assumed the character of an author, having communicated to the Royal Society of Edinburgh, in 1786, a paper on the Determination of the Orbit and Motion of the Georium Sidus, which was published in the Edinburgh Transactions, vol. I. He had observed the opposition of the planet with an equatorial telescope only, and he had computed the elements of its orbit with greater accuracy than any other astronomer had then done; although his suspicion of the effect of such a planet on the motions of Jupiter and Saturn has not been confirmed by later investigations, the irregularities of these planets, on the contrary, having been otherwise explained.

2. A second paper, published in the same collection, vol. ii. p. 82, relates to the Motion of Light, as affected by refracting or reflecting substances which are themselves in motion. The author corrects some errors of Boscovich, who had miscalculated the effect of a water-telescope; but he seems to agree with Dr Wilson in the suggestion of another experiment of a similar nature, which, to say the least, is wholly superfluous.

3. The most important, beyond all comparison, of Professor Robison's scientific publications, are the articles which he communicated from time to time to the third edition of the Encyclopaedia Britannica, and to its Supplement. It was under the care of Mr Colin Macfarquhar that the first twelve volumes of that edition of this work were published; and upon his death, in 1793, the task of continuing it was committed to Dr Gleig, to whom Professor Robison became a most essential co-operator, and from that time "the work ceased to be a mere compilation." The first of his contributions, according to Professor Playfair, was the article Optics, but it is probable he only revised and enlarged that article: it was followed by Philosophy, which he wrote jointly with Dr Gleig; by Physics, Pneumatics, Precession, Projectiles, Pumps, Resistance, Rivers, Roof, Rope-making, Rotation, Seamanship, Signal, Sound, Specific Gravity, Statics, Steam, Steam-Engine, Steelyard, Strength, Telescope, Tide, Trumpet, Variation, and Water-works; and in the

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1 The third edition of the Encyclopaedia Britannica consisted of eighteen volumes; the Supplement to it of two volumes. Robison. Supplement, by Arch, Astronomy, Boscovich, Carpen- try, Centre, Dynamics, Electricity, Impulsion, In- volution, Machinery, Magnetism, Mechanics, Per- cussion, Pianoforte, Position, Temperament, Thun- der, Trumpet, Tschirnhaus, and Watch-work. Not- withstanding some degree of prolixity and want of arrange- ment, which could scarcely be avoided in the preparation of original articles for such a mode of publication, the whole of them, taken together, undeniably exhibit a more com- plete view of the modern improvements of physical science than had ever before been in the possession of the British public; and display such a combination of acquired know- ledge with original power of reasoning, as has fallen to the lot of a few only of the most favoured of mankind.

4. It is not altogether with so high approbation that his friends and his biographers have mentioned a work, of a nature rather political than philosophical, entitled Proofs of a Conspiracy against all the Religions and Governments of Europe, Edinb. 1797, 8vo; though it went through several editions. The principal part of the book consists of the history of the Illuminati and the German Union, whom he considers as having become the chief agents in a plot first formed by the freemasons, at the suggestion of some ex- jesuit, who proposed for their model the internal economy of the order which he had quitted; and whatever founda- tion this outline may have had in truth, there is no doubt that the manner in which Professor Robison has filled it up, betrays a degree of credulity extremely remarkable in a person used to calm reasoning and philosophical demon- stration: for example, in the admission of a story told by an anonymous German author, that the minister Turgot was the protector of a society that met at Baron d'Hol- bach's, for the purpose of examining the brains of living children, in order to discover the principle of vitality. He does not accuse the English freemasons of having partici- pated in the conspiracy; but he considers the continental lodges as having been universally implicated in it.

5. After the death of Dr Black, in 1799, he undertook to superintend the publication of his Lectures on Chemistry, which appeared in 1803, 2 vols. 4to. And this task, which was rather laborious than difficult, he executed with equal zeal and ability. He endeavoured to reduce to their just estimate the comparative pretensions of the French and British chemists, though he is somewhat puritanically se- vere in criticizing the literal meaning of the compliments paid to Black by Lavoisier, on which he finds a charge of insincerity.

6. His last publication was the first volume of a series which was to form a complete system, entitled Elements of Mechanical Philosophy, Edinb. 1804, 8vo. It comprehended only Dynamics and Astronomy, and it never became very popular; it was too difficult for the many, who wished for general and philosophical notions only, and not sufficiently precise and demonstrative for the few, who wanted practi- cal and numerical results. In attempting to combine the separate merits of the Exposition du Système du Monde, and of the Mécanique Céleste, the author sacrificed both the popular simplicity of the former, and the mathematical perfection of the latter. A few inaccuracies, which ought not to escape the attention of the reader of the work, have been pointed out in the Imperial Review for March 1805; a journal long since discontinued.

7. The contents of the volume last mentioned, together with some manuscripts intended to have formed part of a second, and the greater part of the articles furnished by Professor Robison to the Encyclopaedia, were collected into a System of Mechanical Philosophy, with Notes, by David Brewster, LL.D. Edinb. 1822, 4 vols. 8vo; a spirit- ed bookseller in London having undertaken the risk of the publication. 1. The first volume begins with the articles Dynamics, Projectiles, Corpuscular Forces, Capil- lary Attraction, Boscovich's Theory, and Rotation, Robi- son as remodelled for the Elements; then follow Strength of Materials, Carpentry, Roof, Construction of Arches, Construction of Centres. 2. The article Steam-Engine is enriched with notes and an appendix by the late Mr Watt: the next is Machinery, then Re- sistance of Fluids, Rivers, Water-works, Pumps. 3. Astronomy, Telescope, Pneumatics. 4. Electrici- ty, Magnetism, Variation, Temperament, Trumpet, Watch-work, and Seamanship. The notes are not nu- merous, and the editor's principal labour has been to re- trench some passages that appeared to him superfluous when the papers were to stand as parts of such a collection.

"Although Dr Robison's name," says Dr Brewster in his preface, "cannot be associated with the great discoveries of the century which he adorned, yet the memory of his talents and his virtues will be long cherished by his coun- try. Imbued with the genuine spirit of the philosophy which he taught, he was one of the warmest patrons of ge- nius wherever it was found. His mind was nobly elevated above the mean jealousies of rival ambition, and his love of science and of justice was too ardent to allow him either to depreciate the labours of others, or to transfer them to himself. To these great qualities as a philosopher, Dr Ro- bison added all the more estimable endowments of domes- tic and of social life. His friendship was at all times ge- nerous and sincere. His piety was ardent and unosten- tious. His patriotism was of the most pure and exalted character; and, like the immortal Newton, whose memory he cherished with a peculiar reverence, he was pre-em- inently entitled to the high distinction of a Christian, patriot, and philosopher." His person was handsome, and his phy- siognomy prepossessing; and he appears to have been en- dowed with an extraordinary combination of talents, even exclusively of those which were called into immediate ac- tivity in his professional pursuits; for he was a good lin- guist, an excellent draughtsman, and an accomplished mu- sician. His conversation was always energetic and inter- esting, and sometimes even poetical; and his liberality of sentiment was only limited by his regard for what he con- sidered as the best interests of mankind.

A short account of his life was published in 1802, by a contributor to the Philosophical Magazine, who, among other inaccuracies, thought himself at liberty to assert that he was an admirer of the algebraical form of representation, in preference to the geometrical. His friend Dr Gieg soon after stepped forward to correct these mistakes, in the Antijacobin Review for 1802, and his letter was copied into the Philosophical Magazine. He asserts, from his own knowledge, that even yet Professor Robison "delights much more in geometry than in any of the modes of alge- bra, assigning as the reason of his preference, that in the longest demonstration the geometrician has always clear and adequate ideas, which the most expert algebraist can very seldom have." It may perhaps be asserted, on the other hand, that the same reasoning would lead us always to employ actual multiplication or division, in preference to the use of logarithms or of a sliding rule; and that the whole of the magic of calculation depends on the abstrac- tion of the results from the numerous and separately unim- portant steps by which they are obtained; but the having once seen those steps clearly is certainly of great impor- tance to the process of reasoning, even when the memory no longer retains them; and no mathematician of correct taste can study the ancient geometricians without admiring the elegance and precision of their method, even amidst the pedantry which too frequently envelopes their expressions, and without being grateful for their punctuality in collect- ing their results into the very convenient form of distinct propositions, and in making such references from each pro- position to the foundations on which it depends, as to es- able him readily to trace back their steps to the most elementary principles; which is scarcely possible in any of the works of the most modern school of analysis. Professor Robison, however, seems rarely to have cultivated the higher mathematics for their own sake only, or any further than as they could be applied to the study of the phenomena of nature, or to the practice of the combinations of art: in fact, without some such limitation, there would be no track to guide us in the pathless regions of quantity and number, and their endless relations and functions. But besides the utility of the pure mathematics as a branch of early education, in exercising and fortifying the powers of the mind, it is impossible to foresee with certainty how much of mathematics may be wanted by the natural philosopher in any given investigation; and Professor Robison, as well as many others of his countrymen, would certainly have been the better for the possession of a little more, as the author of the criticisms in the Imperial Review has already had occasion to remark.

Philosophical Magazine, xiii.; Dr Gleig, in Antijacobin Magazine, xi. 1802; Stark's Biographia Scotica; Aikin's General Biography, viii. Lond. 1813, 4to; Playfair, in Edinb. Trans. vii. 1815, p. 495; Chalmers's Biographical Dictionary, xxv. Lond. 1816, 8vo.