was actively employed upon his labors, while the night, or his idle hours, as he called the time for sleep, was devoted to study. It was during this double occupation, that Mr. RITTENHOUSE projected and completed an instrument which required the union of knowledge and mechanical skill of the highest order; this was his Orrery, which he succeeded in making more complete than had been done by former astronomers. A description of this great instrument will be found in the first volume of the Transactions of the American Philosophical Society; this Orrery was purchased by Princeton college, New Jersey, where it still remains. It exhibits the positions of the planets and their satellites at any given period of the world; past, present, or future; thus forming a perpetual astronomical almanac, where the results, in lieu of being found in tables, are actually exhibited to the sight. He completed a second, after the same model, for the college of Philadelphia, now the University of Pennsylvania, where it still is. This extraordinary instrument commanded the wonder and admiration of the learned from every part of the world.

A genius of such superior order could not long remain in obscurity; the fame of his Orrery spread far and wide. Several gentlemen, among whom were his brother-in-law, the Rev. Dr. Barton, Dr. Smith, and an ingenious mathematician, named John Lukens, appreciating more fully his talents, united in inviting him to take up his residence. in Philadelphia, where his opportunities for acquiring knowledge and fame, would be enlarged; yielding, not without reluctance, he removed to that city in the year 1770, where he continued to manufacture mathematical instruments, which were acknowledged to be superior to any imported. Having previously joined the American Philosophical Society, he made a communication to that body, respecting the transit of Venus, as it would occur on the 3d of June, 1769, and was appointed on the committee to observe it in the township of Norriton, In the preparations for this observation, he was extremely active and useful; the management and construction of the apparatus being perfectly familiar to him. This phenomenon had been seen but twice by the inhabitants of our earth; it would never be again visible to any person then alive; on it depended many astronomical calculations: under such circumstances, our young star-gazer was of course in a state of mental excitement and solicitude. The sun of that day rose without a cloud; the moment of observation came-the great event occurred as RITTENHOUSE predicted, and so excited was he at the circumstance, that in the instant of one of the contacts of the planet with the sun, he actually fainted with emotion. His report was

received with satisfaction by the learned, everywhere, and acquired him an extended reputation.

In 1775, he delivered the annual oration before the Philosophical Society; it was marked by ingenious though simple language, and comprehended a lucid history of astronomy. Though delivered in a feeble tone of voice, and without the graces of the practised orator, it commanded profound attention from the audience. Astronomy was his favorite study, and the theme of the greater part of his communications for the society's transactions.

Pennsylvania viewed with pride the accession of so valued a son, and soon took care to provide for talents so uncommon; he was employed in several geodetic operations involving a considerable stake. In 1779, the legislature appointed him one of the commissioners to settle the boundary between Pennsylvania and Virginia; this he was mainly instrumental in terminating satisfactorily in 1783. In 1784, he assisted in determining the length of five degrees of longitude, from a point on the Delaware, in order to fix the western limits of the state, and in 1786, he fixed the northern line between New York and Pennsylvania. He performed the same service for New York and New Jersey, in 1769; and in 1787, he was called upon to ascertain the boundary line between Massachusetts and New York. This occupation led him to long and lonely rambles in the wilderness, to which he carried with him his habits of inquiry and investigation; but we do not find any mention of particular acquisitions thereby obtained to natural history.

In 1791, he was elected to fill the chair of president of the American Philosophical Society, vacant by the death of Dr. Franklin/ His attachment to the society was evinced by a donation to its funds of the sum of three hundred pounds.

Though so ardently attached to the study of his choice, he had paid attention to theology, and was well acquainted with practical metaphysics; a great reader, a musician, and a poet; had acquired an intimate knowledge of the French, German, and Dutch languages, in which he took delight to peruse the works of the learned of those countries. His name was known and revered in every place where science was respected. Wherever he went, he was honored. As president of the society, he was much esteemed for his bland and unassuming manners, as well as for his affectionate regard for others.

He received the degree of master of arts, in 1768, from the college of Philadelphia, and the same honor was conferred upon him by the college of William and Mary, in Virginia, in 1784. The college of

New Jersey made him a doctor of laws, and he was elected a member of the American Academy of Sciences, at Boston, in 1782, and of the Royal Society of London, in 1795.

RITTENHOUSE was not only practically a Christian, but he believed emphatically in the Christian Revelation; forming another triumph over the vague assertion that men of genius are unbelievers. Newton and RITTENHOUSE will outweigh a host of thoughtless blasphemers. His beloved country occupied much of his thoughts, and was the object of the affections of his heart, Educated a republican by his father, he was firm to the principles of the revolution. In 1777, Dr. RITTENHOUSE was appointed treasurer of Pennsylvania; this office he held by an annual and unanimous vote of the legislature, till 1789. In 1792, he reluctantly accepted the appointment of Director of the Mint of the United States; this office his ill health obliged him to resign in 1795. His conduct was here above suspicion; his colleague in office having declared, that he even paid for work done at the mint, out of his own salary, where he thought the charges would be considered unreasonable.

His economy extended to a wise and profitable use of his time; he was never unemployed, giving once as an apology for detaining a friend a few minutes, while he arranged some papers he had been examining, that "he had once thought heaith the greatest blessing in the world, but that he now thought that there was one thing of much greater value, and that was time." The philosopher was a stranger to pride and imposture in every thing. His immediate family constituted his chief society, and when the declining state of his health rendered social intercourse more pleasing than solitary study, he passed his evenings in reading or conversation with his wife and daughters.

His house and style of living, exhibited the taste of a philosopher, the simplicity of a republican, and the temper of a Christian. With his estate, though small, he was content: his mind was his fortune; avarice found no place in a breast which could calculate the stars, and estimate, at its true value, the fleetness of time and the length of eternity. Happy, indeed, is that family, where such just ideas prevail; there content waits upon cheerfulness, and the hope of immortality fortifies against the fear of death.

His constitution was naturally feeble, and he had impaired it by sedentary labor, and assiduous midnight study. A weak breast was the result, and whenever he made unusual exertions of body or mind, or during sudden changes of temperature, it became the seat of a

painful and harassing disorder. His last illness was short and painful; but his patience and kind feelings never forsook him while life remained. Upon being told that some of his friends had called to inquire how he was, he asked why they were not invited into his chamber to see him? "Because," said his wife, "you are too weak to speak to them." "Yes," he said, "but I could still have squeezed their hands." Thus, with a heart overflowing with love to his family, his friends, country, and to the whole world, he peacefully resigned his spirit into the hands of his God.

Dr. Rush, his intimate friend, has thus described his person and manners; "The countenance of Mr. RITTENHOUSE was too remarkable to remain unnoticed. It displayed such a mixture of contemplation, benignity, and innocence, that it was easy to distinguish his person in the largest company, by a previous knowledge of his character. His manners were civil and engaging to such a degree, that he seldom passed an hour, even in a public house, in travelling through our country, without being followed by the good wishes of all who attended upon him. There was no affectation of singularity, in any thing he said or did; even his hand-writing, in which this weakness so frequently discovers itself, was simple and intelligible at first sight, to all who saw it.

"Here I expected to have finished the detail of his virtues, but in the neighborhood of that galaxy created by their connected lustre, I behold a virtue of inestimable value, twinkling like a rare and solitary star. It is his superlative modesty. This heaven-born virtue was so conspicuous in every part of his conduct, that he appeared not so much to conceal, as to be ignorant of, his superiority as a philosopher and a man, over the greatest part of his fellow-creatures."

In stature, Dr. RITTENHOUSE was somewhat tall; in his person, slender and straight; and although his constitution was delicate, his bodily frame did not appear to have been originally weak; his gait was quick, and his general movements lively; his face was of an oval form; his complexion fair, with brown hair in youth, somewhat whitened by age. All his features were good; forehead high, capacious and smooth; his grayish-colored eyes expressed animation, reflection, and good nature. In his temper, he was naturally placid and good humored, yet sometimes grave and inclined to pensiveness; in proportion to his means, he was remarkably charitable. He loved quiet and order, and preferred retirement to the bustle of the world. He considered ambition, pomp, and ostentation, as being generally inconsistent with true happiness.

Professor Barton, the deceased's nephew and friend, who attended him in his last illness, states, that after doing something to alleviate his pain, he asked him if he did not feel easier; "he calmly answered in these memorable words, which it is impossible for me to forget, for they were the last he ever distinctly uttered, and they make us acquainted with the two most important features of his religious creed; 'Yes, you have made the way to God easier!"

The remains of this distinguished philosopher were deposited, agreeably to a desire he had expressed long before his death, beneath the pavement within the small observatory which he had erected many years before, in the garden adjoining his house. The house is still standing at the north west corner of Arch and Seventh streets, but the observatory has disappeared to make way for modern improvements, and the body now rests in the cemetery adjoining the Presbyterian church in Pine street, Philadelphia, near the body of his sonin-law, Mr. Sergeant. The grave of the American astronomer is enclosed under a plain marble slab, thus inscribed :

IN MEMORY OF

DAVID RITTENHOUSE,

BORN APRIL 18тн, 1732,
DIED JUNE 26TH, 1796;

AND

HANNAH RITTENHOUSE,

HIS WIFE,

WHO DIED OCTOBER 15th,

1799,

AGED 64 YEARS.

Mr. Jefferson succeeded him as president of the Philosophical Society. That individual, in his refutation of the Count de Buffon's preposterous theory, "of the tendency of nature to belittle her productions on this side the Atlantic," has said, after mentioning in proper terms, Washington and Franklin, &c., "we have supposed RITTENHOUSE second to no astronomer living; that in genius he must be the first, because he is self-taught. As an artist, he has exhibited as great a proof of mechanical genius as the world has ever produced. He has not indeed made a world; but he has, by imitation, approached nearer his Maker than any mere man who has lived from the creation to this day."

A list of the papers communicated by Dr. RITTENHOUSE to the society of which he was president, will be found in his memoirs, written by William Barton, M. A., and published in Philadelphia in 1813.