hadee. This report, however, is alleged to be without foundation by the late Earl of Bridgewater, in a curious work which he published some years ago at Paris, relative to his predecessor's celebrated canal.

Brindley's multiplied labors, and intense application, rapidly wasted his strength, and shortened his life. He died at Turnhurst, in Staffordshire, on the 27th of September, 1772, in the fifty-sixth year of his age, having suffered for some years under a hectic fever, which he had never been able to get rid of. In his case, as in that of other active spirits, the soul seems to have

"O'er-inform'd its tenement of clay;"

although the actual bodily fatigue to which his many engagements subjected him, must doubtless have contributed to wear him out

No man ever lived more for his pursuit, or less for himself, than Brindley. He had no sources of enjoyment, or even of thought, except in his profession. It is related, that having once, when in London, been prevailed upon to go to the theatre, the unusual excitement so confused and agitated him, as actually to unfit him for business for several days, on which account he never could be induced to repeat his visit. His total want of education, and ignorance of literature, left his genius without any other field in which to exercise itself and spend its strength than that which the pursuit of his profession afforded it: its power, even here, would not probably have been impaired, if it could have better sought relaxation in variety; on the contrary, its spring would most likely have been all the stronger for being occasionally unbent. We have already mentioned that he was all but entirely ignorant of reading and writing. He knew something of figures, but did not avail himself much of their assistance in performing the calculations which were frequently necessary in the prosecution of his mechanical designs. On these occasions his habit was to work the question by a method of his own, chiefly in his head, only setting down the results at particular stages of the operation; yet his conclusions were generally correct. His vigor of conception, in regard to machinery, was so great, that however compli cated might be the machine he had to execute, he never, except sometimes to satisfy his employers, made any drawing or model of it; but having once fixed its different parts in his mind, would construct it without any difficulty, merely from the idea of which he had thus possessed himself. When much perplexed with any problem he had to solve, his practice was to take to bed, in order to study it; and he would sometimes remain, we are told, for two or three days thus fixed to his pillow in meditation.

Had it not been for the example set by his adventurous genius, the progress of artificial navigation in Great Britain would proba bly have been timid and slow, compared to what it has been. For a long time, in all likelihood, the only canals would have been a few small ones, cut in the more level parts of the country, the benefit of each of which would have been extremely insignificant, and confined to a very narrow neighborhood. He did, in the very infancy of the art, what has not yet been outdone; struggling, indeed, with such difficulties, and triumphing over them, as could be scarcely exceeded by any his successors might have to encounter. By the boldness and success with which, in particular, he carried the grand Trunk Navigation across the elevated ground of the midland counties, he demonstrated that there was hardly any part of the island where a canal might not be formed; and, accordingly, this very central ridge, which used to be deemed so insurmountable an obstacle to the junction of the opposite coasts, is now intersected by more than twenty canals besides the one which he first drove through the barrier. It is in the conception and accomplishment of such grand and fortunate deviations from ordinary practice that we discern the power, and confess the value, of original genius.

The case of Brindley affords us a wonderful example of what the force of natural talent will sometimes do in attaining an acquaintance with particular departments of science, in the face of almost every conceivable disadvantage-where not only all education is wanting, but even all access to books.

JESSE RAMSDEN.

JESSE RAMSDEN was born in 1735, at Salterhebble, near Hali. fax, where his father kept an inn. The education he received in his boyhood embraced both a litt'e Latin and the elements of geometry and algebra. But when he was of the usual age for being put to a business, his father took him from school, and bound him apprentice to a clothier in Halifax; and in this line he continued till he reached his twentieth year, when he came up to London, and obtained employment as a clerk in a wholesale warehouse. He held this situation for about two years and a half; but in the mean time he had industriously availed himself of what leisure he could command to renew and extend his acquaintance

with science; and so enamoured did he gradually become of the pursuits, that he at last resolved to make an effort to establish himself in some line more closely connected with his favorite studies than that which he had heretofore followed. With this view, notwithstanding that he was now so far beyond the age at which the learning of a business is usually begun, he bound himself apprentice for four years to Mr. Burton, of Denmark-court, a mathematical instrument maker. On the expiration of this term, he and a fellow-workman of the name of Cole entered into business together, Ramsden serving the other as journeyman at a salary of twelve shillings per week. This connection, however, did not last long; and on its termination Ramsden opened a shop of his own. His chief employment for some time consisted in repairing optical and other mathematical instruments which had got out of order; and in this the industry and ability he displayed soon brought him into notice, and procured him a rapidly increas ing business. But he did not rest satisfied with merely performing in a superior manner such work as he undertook of this descrip tion; the different instruments which passed through his hands forcibly attracted his attention to the imperfections by which each happened to be characterized, and called his powers of contrivance into exercise in devising how they might be improved. In order to accomplish himself the more completely for this task, he labored assiduously till he acquired, entirely by his own application, the art of grinding glass, and of handling the file, the lathe, and the other instruments used by opticians. Thus furnished with the practical skill and dexterity requisite to enable him to apply his ingenuity and mathematical knowledge, he proceeded to enter upon a regular and comprehensive examination of all the different optical instruments in use, with a view to the remedying of their several defects.

This resolution, and the perseverance with which it was followed up, eventually made Ramsden one of the greatest optical mechanicians that the world has ever produced. The list of the instruments which are indebted to him for the most ingenious and valuable improvements, embraces nearly all those of greatest im portance and most common use in astronomy and the connected sciences. Hadley's quadrant, the sextant, the theodolite, the baro. meter, the transit instrument, and many others too numerous to specify, all came out of his hands, it might almost be said, with new powers, and certainly, at all events, with much more in every case than they before possessed, both of manageableness and of accuracy. In this last respect, especially, the instruments con "tructed by him far surpassed any that had before been produced;

and they were indebted for much of their superiority to a new dividing or graduating engine which he had contrived, the prin ciple of which was extremely ingenious. It consisted essentially of a marker moved forward by the turning of a very fine-threaded screw. It is easy to make a screw with a hundred turns of the thread in an inch; and by attaching to it a handle or index of sufficient length, so that the extremity may be over a properly divided circle of considerable magnitude, the movement of such a screw may be regulated with perfect precision to the thousandth part of one of its entire revolutions. Now, as by such a revolu tion it would only advance the marker the hundredth part of an inch, it is evident that, by being turned only the thousandth part of an entire revolution every time the marker is allowed to descend and make an impression upon the plate of metal or other surface to be divided, a hundred thousand equidistant lines may actually be drawn upon every inch of that surface. For this most useful

contrivance the Board of Longitude awarded him a premium of £615; and in return he engaged to graduate whatever sextants were put into his hands for that purpose, at the rate of three shillings a-piece. His engine, indeed, enabled him to perform the operation in about twenty minutes, whereas it had been wont to occupy many hours. But the additional accuracy which was given to the instrument to which it was applied by the new method, was of still greater importance than its comparative expedition and cheapness. Hadley's quadrant, for instance, used to be so coarsely divided, and in other respects so defectively made, before it re ceived Ramsden's improvements, that, in endeavoring to ascertain the longitude by it, the observation might in some cases lead to an error of fifty leagues; but Ramsden constructed it in so superior a manner, that even his commonest instruments did not admit of an error being fallen into of more than the tenth part of that amount, and with those of a more expensive description accuracy was ensured in all cases to within a single league.

Soon after he commenced business, Ramsden married Miss Dollond, daughter of the inventor of the achromatic telescope, part of the patent for which came in this way into his possession. In 1786 he was elected a Fellow of the Royal Society, having been proposed by his friends without his knowledge, after his diffidence in his claims to such a distinction had made him long withhold his consent to their taking that step. In 1794 he was chosen a member of the Imperial Academy of Sciences at Petersburg; and in 1795 the Royal Society awarded him the gold medal annually bestowed by them for eminence in science.

The Reverend Lewis Dutens, the author of the "Researches on

the Origin of Discoveries," who was intimately acquainted with Ramsden, has given us an account of his friend, which contains some interesting particulars of his character and habits. After noticing his great activity, the uncommon force of his reasoning powers, and the accurate and retentive memory with which he was endowed, the writer proceeds to remark, that perhaps, after all, the most distinguishing quality of his mind was a certain elegance, and taste for precision and high finish, which appeared not more in the instruments he manufactured than in every thing he did. "This feeling for perfection," Mr. Dutens goes on to say, "led him, in the most minute and insignificant parts of his instru ments, to a polish and grace, which sometimes tempted those to smile who did not perceive that the same principle which enabled him to carry the essential parts of his instruments to a degree of perfection unknown, and considered as impossible before his time, induced him to be dissatisfied if a blemish of any sort, even the most trifling, appeared to his exquisite eye. To these uncom monly strong natural endowments he added all that the most constant and intense study could bestow. Temperate to abstemious. ness in his diet, satisfied with an extremely small portion of sleep, unacquainted with dissipation or amusement, and giving but very little time even to the society of his friends, the whole of those hours which he could spare from the duties of his profession were devoted either to meditation on farther improvements of philo. sophical instruments, or to the perusal of books of science, parti. cularly those mathematical works of the most sublime writers which had any connection with the subjects of his own pursuits. Mr. Ramsden's only relaxation from these constant and severe studies was the occasional perusal of the best authors both in prose and verse; and when it is recollected that at an advanced age he made himself so completely master of the French language as to read with peculiar pleasure the works of Boileau and Moliere, he will not be accused of trifling even in his lighter hours. Short and temperate as were his repasts, a book or a pen were the con. stant companions of his meals, and not seldom brought on a forgetfulness of hunger; and when illness broke his sleep, a lamp and a book were ever in readiness to beguile the sense of pain, and make bodily sickness minister to the progress of his mind. Of the extent of his mathematical knowledge he was always from innate modesty averse to speak, although I have heard him say that he never was at a loss when his profession required the ap plication of geometry. His knowledge in the science of optics is well known to have been perfect; and when we add that the works of Bouguer and the great Leonard Euler were his favorite study