During that portion of his life in which this youthful philosopher pursued the ordinary occupations of a husbandman, which continued until about the eighteenth year of his age, as well as in his earlier youth, he appeared to have inherited from healthful parents a sound constitution, and to have enjoyed good health.
It was at this period, or rather about the seventeenth year of his age, that he made a wooden clock, of very ingenious workmanship: and soon after, he constructed one of the same materials that compose the common four-and-twenty hour clock, and upon the same principles. But he had exhibited much earlier proofs of his mechanical genius, by making, when only seven or eight years old, a complete water-mill in miniature.
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.
It was in this interval and by these means, that our young philosopher impaired his constitution, and contracted a pain in his breast; or rather, as he himself described that malady to the writer, “a constant heat in the pit of the stomach, affecting a space not exceeding the size of half a guinea, attended at times with much pain;” a sensation from which he was never exempt, during the remainder of his life. About this time, he retired from all business, and passed several weeks at the Yellow Springs, distant but a few miles from his place of residence. He there bathed and drank the waters; and from the use of this chalybeate, he appeared to have derived some benefit to his general health, though it afforded little alleviation of the pain in his breast.
A due regard to the sacredness of historic truth demands, that some circumstances which occurred while Mr. Rittenhouse was yet a youth, and one which it is believed had a very considerable influence on his subsequent pursuits and reputation, should now be made known. Because the writer of these memoirs conceives he ought not to be restrained, by motives which would appear to him to arise from a mistaken delicacy, from introducing into his work such notices of his own father, long since deceased, as do justice to his memory; while they also serve to elucidate the biographical history of Mr. Rittenhouse.
In the year 1751, when David Rittenhouse was about nineteen years of age, Thomas Barton, who was two years elder than David, opened a school in the neighbourhood of Mr. Matthias Rittenhouse. It was while Mr. Barton continued in that place, supposed to have been about a year and a half, that he became acquainted with the Rittenhouse Family; an acquaintance which soon ripened into a warm friendship for young Mr. Rittenhouse, and a more tender attachment to his sister, Esther.
Two years afterwards (in 1753), the personal attractions and fine understanding of the sister rendered her the wife of Mr. Barton; who, for some time before, had officiated as one of the tutors in the then recently-established Academy, afterwards College, of Philadelphia; now the University of Pennsylvania. In this station, he continued until the autumn of 1754; when he embarked for England, for the purpose of receiving episcopal ordination in the church, and returned to Pennsylvania in the early part of the following year.
The very intimate connexion thus formed between Mr. Barton and a sister of Mr. Rittenhouse (who was two years elder than this brother), strengthened the bands of friendship which had so early united these young men: a friendship affectionate and sincere, and one which never ceased until Mr. Barton’s death, nearly thirty years afterwards; notwithstanding some difference of political opinions had arisen between these brothers-in-law, in the latter part of that period, in consequence of the declaration of the American independence.