The Manuscript Observations and Calculations Relating to Time, Longitude and Latitude of Early University of Pennsylvania Astronomer Robert M. Patterson

He made these unpublished calculations on board a vessel in the Atlantic Ocean, and was, along with his father, a friend of Thomas Jefferson; he was a prominent member of the Philosophical Society and would later be its President

The American Philosophical Society in Philadelphia was the hub of knowledge and its pursuit in the early United States. Among its early members were America’s most prominent scientists of the time, including Thomas Jefferson, and Robert Patterson, early mathematician and perhaps the preeminent astronomer of his generation. Both served in leadership of the Society for a period, and both were among a select few to prepare Meriwether Lewis for his expedition.

In 1779, after the College and Academy of Philadelphia were reorganized into the University of Pennsylvania, Patterson successfully applied to John Ewing, the Provost, for employment as Professor of Mathematics. Patterson was Professor of Mathematics from 1779 to 1810, Professor of Natural Philosophy and Mathematics from 1810 to 1813 and Vice-Provost from 1810 to 1813. Because he performed his official duties with integrity, industry and ability, also rendering essential services to the University, he was granted an honorary Master of Arts in 1788 and an honorary Doctor of Laws in 1819. After presenting his resignation in 1814, Patterson was succeeded as Professor of Mathematics as well as Vice-Provost by his son, Robert M. Patterson.

Like Meriwether Lewis, the younger Patterson (Robert Maskell Patterson) was a pupil of his father in the fields of mathematics and astronomy. Dr. Patterson left Paris, where he had studied medicine, in 1811 for London, where he spent a year, and heard the last course of lectures delivered by Sir Humphry Davy; and in 1812 he returned home. In 1813 he was appointed professor of natural philosophy in the medical department of the University of Pennsylvania, and a year after (March, 1814) was elected to the chair of mathematics, chemistry, and natural philosophy, in the faculty of arts. In this last he was successor to his father. A month later he was made vice-provost.

Patterson father and son led parallel careers. Both were prominent Penn professors, astronomers, friends and correspondents with Thomas Jefferson, and members of the Philosophical Society. Robert M. Patterson (son) was the youngest person elected to the American Philosophical Society at 22 in 1809. Four years later he was elected a secretary, the a vice-president in 1825. It was he who informed Jefferson of his re-election as President, a position he would later occupy.

His return vessel from Europe was an opportunity for Patterson to make celestial observations, calculating latitude, longitude, time, and magnetic variation, using new techniques to do so aboard a vessel. These calculations show the young Patterson applying the contemporary methods for these. They were acquired from the direct descendants and have never before been offered for sale. They stretch from July 21 through July 25 and cover a wide range of Atlantic Ocean celestial observations.

Autograph manuscript, in the hand of Robert M. Patterson, 12 pages, some portions missing, having been long ago ripped off, although most remains. The manuscript begins on July 22, noting “sine per watch”, going on to note the “moon’s mer. dist.” On this first page, he is determining the exact time. He notes the location of the sun and moon.

Page two shows him establishing a formula for finding time, using certain figures, and then going on to calculate the time by “time by equal altitudes.” These are on the 23rd and 24th of July.

The third page is entitled “Longitude” and begins on July 22: “The following set of observations was taken by a single observer.” Includes detailed observations and calculations. He notes that the “distances are reduced by Mackay’s second method. The formula is constructed upon the…. and in the University of Pennsylvania,” a reference to a method employed first there. This is a reference to “Mackay’s Treatise on the theory & practice of finding the longitude at sea” published in 1801.

The fourth page lists Mackay’s second method per above and notes more celestial observations. Fifth page is the same using Mackay’s first method.

The sixth page is the measurement of latitude dated July 24, 1812.

The seventh page is “Magnetic Variation,” or the calculation of the difference between true and magnetic north, writing notations on July 22 and 25. He references Bowditch’s early 19th century work on this subject.

The final pages involve observations of dolphins, water spouts, etc…, as well as poetry from Falconer that he liked.