of gravitation near its surface is such, that falling bodies descend only through fourteen feet, during the first second, instead of thirty-two feet, as with us. Herschel afterwards discovered, successively, no fewer than six satellites, or moons, belonging to his new planet.

The announcement of the discovery of the Georgium Sidus, at once made Herschel's name universally known. In the course of a few months, the King of Great Britain bestowed upon him a pension of three hundred pounds a-year, that he might be enabled entirely to relinquish his engagements at Bath; and upon this, he came to reside at Slough, near Windsor. He now devoted himself entirely to science; and the constructing of telescopes, and the observation of the heavens, continued to form the occupations of the remainder of his life. Astronomy is indebted to him for many other most interesting discoveries besides the celebrated one, of which we have just given an account, as well as for a variety of speculations of the most ingenious, original, and profound character. But of these, we cannot here attempt any detail. He also introduced some important improvements into the construction of the reflecting telescope, besides continuing to fabricate that instrument of dimensions greatly exceeding any that had been formerly attempted, and with powers surpassing, in nearly a corresponding degree, what had ever before been obtained. The largest telescope, which he ever made, was his famous one forty feet long, which he erected at Slough, for the King. It was begun about the end of the year 1785, and on the 28th of August, 1789, the enormous tube was poised on the complicated, but ingeniously contrived mechanism, by which its movements were to be regulated, and ready for use. On the same day a new satellite of Saturn was detected by it, being the sixth which had been observed attendant upon that planet. A seventh was afterwards discovered by means of the same instrument. This telescope has since been taken down, and replaced by another, of only half the length, constructed by Mr. J. Herschel, the distinguished son of the subject of our present sketch. Herschel, himself, eventually became convinced that no telescope could

surpass in magnifying power, one of from twenty to twenty-five feet in length. The French astronomer, Lalande, in his continuation of Montucla's History of the Mathematics, states, that he was informed by George III., himself, that it was at his desire that Herschel was induced to make the telescope at Slough of the extraordinary length he did, his own wish being that it should not be more than thirty feet long.

So extraordinary was the ardor of this great astronomer in the study of his favorite science, that for many years, it has been asserted, he never was in bed, at any hour during which the stars were visible. And he made almost all his observations, whatever was the season of the year, not under cover, but in his garden, and in the open air and generally without an attendant. There was much, that was altogether peculiar to himself, not only in the process by which he fabricated his telescopes, but also in his manner of using them. One of the attendants in the King's observatory at Richmond, who had formerly been a workman in Ramsden's establishment, was forcibly reminded, on seeing Herschel take an observation, of a remark which his old master had made. Having just completed one of his best telescopes, Ramsden, addressing himself to his workmen, said, "This, I believe, is the highest degree of perfection that we, opticians by profession, will ever arrive at; if any improvement of importance, shall ever, after this, be introduced in the making of telescopes, it will be by some one who has not been taught his art by us."

Some years before his death, the degree of Doctor of Laws was conferred upon Herschel by the University of Oxford; and in 1816, the then Prince Regent, afterwards George IV., bestowed upon him the Hanoverian and Guelphic Order of Knighthood. He died on the 23d of August, 1822, when he was within a few months of having completed his eighty-fourth year.

To this distinguished name, and those of Dollond and Ramsden, it would be easy, if our space permitted, to add those of many other self-taught cultivators of the same departments of science. Among more recent opticians,

no one has attained a higher eminence, either as an artist or as a scientific experimentalist and speculator, than FRAUNHOFER, the late superintendent of the establishment for the manufacture of optical glasses at Munich, who rose from the condition of a common workman.

Of astronomical observers, again, some might also be mentioned, who have been of very humble station. There is a print a copy of which may be seen in the rooms of the [London] Astronomical Society-of two very remarkable individuals, who were employed, during a considerable part of the last century, in the Earl of Macclesfield's observatory, at Sherburn, England. The elder of these, as the inscription below the engraving informs us, was named THOMAS PHELPS, and he, it is stated, "from being a stable-boy, in the year 1718, to the then Lord Chief Justice Parker, afterwards Earl of Macclesfield, rose by his merit to the upper employments in the family, and at last, for his uncommon genius, was promoted to be Observer in the observatory at Sherburn Castle." Phelps, it is added, was born at Chalgrove, in Oxfordshire, in January, 1694, and was in his eightysecond year, when his portrait was taken.

The other, JOHN BARTLETT, is described as having been "originally a shepherd, in which station, he, by books and observation, acquired such a knowledge in computation, and of the heavenly bodies, as induced the late George, Earl of Macclesfield, to appoint him Assistant Observer in his observatory at Sherburn Castle." Bartlett was born at Stoke Talmage, in Oxfordshire, August 22, 1721, old style, and was in his fifty-fourth year, at the time his picture was taken. In the print, Phelps is represented as standing and looking through a telescope, while Bartlett is sitting by him with his tablets, or a sheet of paper, in the one hand, and a pen in the other, ready, seemingly, to note down what his associate may announce. There is a penetrating eagerness and sagacity, in the eye and general aspect of the old man; and that of the other is also a striking head, with a less keen and vivacious physiognomy than Phelps, but more massive, and indicating, perhaps, more a meditative and cal

culating mind. In a manuscript note, on the back of the copy of this print, which belongs to the Astronomical Society, it is stated, that "Phelps was the person, who, on the 23d of December, 1743, discovered the great comet, and made the first observation of it; an account of which is contained in the Philosophical Transactions, but not the name of the observer."

The comet of 1758, so famous in consequence of its return having been predicted more than half a century before, by the great astronomer, Halley, was also, it may be remarked, first perceived by an observer in an humble. rank of life. It was on the 25th of December, in that year, that the luminary in question was detected with only the naked eye, at Prohlis, near Dresden, by a Saxon peasant, of the name of PALITZCH, at a time, when all the greatest astronomers in Europe were seeking for it in vain, with their telescopes. Nor did Palitzch owe his discovery merely to his superior powers of vision.

This Saxon peasant was really an astronomer. "George Palitzch," says Lalande, born in the obscure condition of a common laborer, had succeeded both in finding happiness in his humble lot, and in acquiring various branches of knowledge, which are rarely found possessed by men of higher stations who have had the advantage of a careful education. More in the way of being struck with the spectacle of the heavens, than if he had lived in a town, he had, by his own efforts, studied and made himself master of astronomy, as well as those parts of geometry, such as plane and spherical trigonometry, upon which it depends. By the exertion of a meritorious economy, he had formed, for himself, an observatory, furnished with the instruments most important for the pursuit of his favorite study. Few opportunities of making interesting observations escaped him; and, notwithstanding this, his occupations as an agriculturist were duly attended to. Natural History and Botany were also among the studies in which he took great delight; and he had a very-well-arranged cabinet of natural productions, as well as a garden full of rare plants, which he carefully cultivated. He was distinguished by such exceeding modesty, that he always refused

even to give any details of his life, notwithstanding they must have been so full of interest. Such was the astron

omer and philosopher Palitzch, to whom was reserved the honor of being the first of all the astronomers of Europe, in the discovery of the return of this anxiously expected comet." Palitzch, we may add, who was born in 1723, continued to cultivate astronomy, as well as his garden and his fields, for many years after this event,— and died, at last, in his native village, in 1788. He had been, for some time, a corresponding member both of the Royal Society of London and of the Imperial Academy of St. Petersburg.

CHAPTER XII.

Discovery and Improvement of the Steam Engine :James Watt.

ALL the inventions and improvements of recent times, if measured by their effects upon the condition of society, sink into insignificance, when compared with the extraordinary results which have followed the employment of steam as a mechanical agent. To one individual, the illustrious JAMES WATT, the merit and honor of having first rendered it extensively available for that purpose are preeminently due.* The force of steam, now so important an agent in mechanics, was nearly altogether overlooked, until within the last two centuries. The only application of it, which appears to have been made by the ancients, was in the construction of the instrument which they called the Eolipile, that is, the Ball of Æolus. The Æolipile consisted of a hollow globe of metal,

*[For a notice of the merits of Fulton, and other Americans, in relation to the employment of steam power, see the LIFE OF FULTON, (particularly chap. vi.) in Vol. I. of ‘Lives of Eminent Individuals,' forming Vol. IV. of 'THE SCHOOL LIBRARY.'-AM. ED.]