Mr. Rittenhouse’s father was a very respectable man: he possessed a good understanding, united to a most benevolent heart and great simplicity of manners. The writer long knew him; and, from his early acquaintance with the character, the appearance, and the habits of this worthy sire of an illustrious son, he had long supposed him to have been inclined to the religious principles of the society called Friends, although he had been bred a Baptist:—but a circumstance which shall be noticed hereafter, will evince the liberality of this good man’s opinions, in the all-important concern of religion. Yet, with truly estimable qualities, both of the head and heart, old Mr. Rittenhouse had no claims to what is termed genius; and therefore did not, probably, duly appreciate the early specimens of that talent, which appeared so conspicuous in his son David. Hence, he was for some time opposed to the young man’s earnest desire to renounce agricultural employments; for the purpose of devoting himself, altogether, to philosophical pursuits, in connexion with some such mechanical profession as might best comport with useful objects of natural philosophy, and be most likely, at the same time, to afford him the means of a comfortable subsistence. At length, however, the father yielded his own inclinations, in order to gratify what was manifestly the irresistible impulse of his son’s genius: he supplied him with money to purchase, in Philadelphia, such tools as were more immediately necessary for commencing the clock-making business, which the son then adopted as his profession. About the same time, young Mr. Rittenhouse erected on the side of a public road, and on his father’s land in the township of Norriton, a small but commodious work-shop; and, after having made many implements of the trade with his own hands, to supply the deficiency of many such as were wanting in his purchased stock, he set out in good earnest as a clock and mathematical instrument maker. From the age of eighteen or nineteen to twenty-five, Mr. Rittenhouse applied himself unremittingly, both to his trade and his studies. Employed throughout the day in his attention to the former, he devoted much of his nights to the latter. Indeed he deprived himself of the necessary hours of rest; for it was his almost invariable practice to sit up, at his books, until midnight, sometimes much later.