Robert Patterson

In 1803 Patterson, the oldest and perhaps the most erudite of the five American Philosophical Society members Lewis came to consult—Jefferson’s letter explicitly asked for instruction—was editing several works on mechanics and astronomy as well as preparing his own book, The Newtonian System. These efforts had merited adding natural philosophy (physical science) to the title of his professorship in mathematics at the University of Pennsylvania. Later to come was his selection as vice-provost. Patterson was already vice-president of the American Philosophical Society, and succeeded to the presidency on the death of Caspar Wistar in 1818.

Many years earlier Patterson had had his own army career. As a 17-year-old, after a year of service in the militia in his native Ireland during the threatened French invasion of the British Isles, he was offered a commission but declined. His experience was useful later when he instructed American infantrymen in military tactics and otherwise served in the early years of the Revolutionary War.

He was acquainted with the practical difficulties of establishing geographic coordinates under adverse and variable conditions. Philadelphia shipmasters and officers who regularly dealt with heaving decks and poor visibility at sea, for example, were attentive students to his lectures on establishing longitude from lunar observations. He had established a school for that purpose shortly after arriving here; one of his most able students was Andrew Ellicott; one of the most prominent was Meriwether Lewis, for whom he prepared the study manual now known as the Astronomy Notebook.

Mathematics and physics were not his only interests. He was a member of the original Board of Visitors to Peale’s Museum, as was Jefferson. Peale credited Patterson’s gift of a preserved paddlefish with the founding of the museum.