Born in 1732, the son of a farmer in Germantown (now part of Philadelphia), Pennsylvania, David Rittenhouse was a leading figure in early American science and one of the most influential Pennsylvanians of the 18th Century. Largely self-educated, Rittenhouse had an early interest in mathematics and began building various types of scientific and mechanical devices, including clocks, at a young age. By age nineteen, Rittenhouse had opened a clock and scientific instrument shop at his father's West Norriton Township farm, and would continue to produce many pioneering and sought after scientific instruments, including two orreries constructed for the College of New Jersey (now Princeton University) and the College of Philadelphia (now the University of Pennsylvania). In addition to his instrument making, Rittenhouse was an accomplished astronomer and surveyor, as well as an active and influential patriot. Rittenhouse was elected to the American Philosophical Society on January 1, 1768 and would hold many offices: Secretary (1771), Librarian (1772), Curator (1772-1776), Vice President (1779-1783 and 1787-1791), Councilor (1783-1789) and President (January 7, 1791-June 26, 1796). In fact, a paper authored by Rittenhouse regarding his orreries was the first scientific paper read at the Society, in 1768.
On June 3, 1769, Rittenhouse was a key participant in the observation of the Transit of Venus across the sun. Rittenhouse built several instruments for the event, and observed the Transit from an observatory he had constructed at his Norriton farm. Rittenhouse, along with compatriots William Smith, provost of the College of Philadelphia and John Lukens, Surveyor-General of Pennsylvania, manned three telescopes for the event, but when the time came to begin the observations, an ill Rittenhouse collapsed, only recovering a third of the way into the Transit.
Using the calculations determined by Rittenhouse after the observation, Smith wrote a report on the event and submitted it, along with a rival report written by John Ewing, to the July 20, 1769 meeting of the American Philosophical Society. Smith, repeatedly citing Rittenhouse's contributions, successfully argued for the report's inclusion in the first volume of the Society's Transactions. Also included in the volume were Rittenhouse's observations of what became known as Lexell's Comet. Through the 1760s, Rittenhouse found himself intellectually isolated due to his residence on the family farm he had inherited from his father in Norriton. Consequently, in the fall of 1770, after the harvest on the farm, Rittenhouse moved with his wife and daughters, then three and one, into the city of Philadelphia, providing him with ready access to his colleagues in astronomy and mathematics. Renting a house at Seventh and Arch (then Mulberry) Streets, Rittenhouse continued his work making instruments, including compasses, levels, mercury thermometers and barometers, as well as eyeglasses. It was in 1771, at his home workshop, that Rittenhouse completed the two orreries for the Colleges of New Jersey and Philadelphia. These instruments were designed to illustrate the position and motion of the planets and their satellites, relative to each other and, according to Rittenhouse, his orreries could project these positions as far as 5000 years into the future. Though never paid in full for his work on the orreries, he received a £300 award from the government of Pennsylvania for his efforts.
Rittenhouse married Eleanor Coulston on February 20, 1766, and the couple had two daughters, Elizabeth and Ester. Eleanor, however, died on February 23, 1771, just after the move to Philadelphia, from complications two days after the birth of the couple's third child, who also died. Rittenhouse married a second time, on December 31, 1772, to Hannah Jacobs. Rittenhouse met with misfortune again in 1773, when their only child died at birth.
Using his talent in instrument making, as well as astronomy and mathematics, Rittenhouse became an active and accomplished surveyor, both before and after the Revolution. In 1769, Rittenhouse assisted in establishing the boundary between New York and New Jersey, and just three years later, in September 1772, Rittenhouse was appointed by the Pennsylvania Assembly to lead a commission tasked with determining the feasibility of building a canal from the Schuylkill River westward to the Susquehanna River. Upon the completion of the survey in 1773, Rittenhouse and his company had determined that not only was a canal between the Schuylkill and the Susquehanna possible, but also that another canal, between the Schuylkill eastward to the Lehigh River, was practicable as well. Work was not started on the canal until the 1780s In response to Connecticut's annexation of land in the Wyoming Valley in northeastern Pennsylvania, In 1774 Rittenhouse, along with Captain Samuel Holland of New York, was tasked with establishing the northern boundary of Pennsylvania. On the return trip to Philadelphia, Rittenhouse surveyed the Delaware River, a task he completed the following spring.
Thanks to his work on various surveying projects, as well as his politically connected friends, Rittenhouse was appointed to the office of City Surveyor of Philadelphia in 1774, his first political post. The position was fleeting, however, due to the coming of the Revolution, when a majority of Rittenhouse's scientific work lost precedence to his participation in the political affairs of Pennsylvania. Rittenhouse firmly believed in American independence and associated himself with the radical patriot movement. Selected by the Pennsylvania Assembly for service on the Committee on Safety in June 1775, Rittenhouse and other dignitaries viewed the row galleys constructed for the defense of the Delaware River in September of that year. Just one month later, Rittenhouse was appointed engineer of the Committee on Safety and, in November, was charged with surveying the Delaware River, paying special attention to its depth and the nature of its shoreline, in order to determine the best way to fortify the river against British attack.
The Committee also asked Rittenhouse to oversee the construction of heavy cannon and the production of saltpeter, a critical component of gunpowder. Though operating outside of his expertise, Rittenhouse eventually became an expert on explosives and ballistics, proposing such improvements as rifling heavy cannon (the improvement could not be implemented during the War).
On March 2, 1776, Rittenhouse was elected to the Pennsylvania Assembly to fill Benjamin Franklin's open seat, and served on the Assembly's Committee on Safety. On July 8 of that year, Rittenhouse was elected to the Pennsylvania Constitutional Convention. Rittenhouse, a firm believer in elective and representative government, allied himself with the radical members of the Convention. Rittenhouse proved himself capable of restraining his beliefs for the good of Pennsylvania, particularly when he attempted to limit punishments against counterfeiters and British Loyalists (the Convention dismissed his efforts and eventually adopted much harsher punishments than Rittenhouse advocated.). Although records of his exact contributions to the Convention are unclear, Rittenhouse undoubtedly played an active role in formulating the Pennsylvania constitution.
When the Constitutional Convention established a Council of Safety to supersede the Committee on Safety, Rittenhouse was appointed to the new body to oversee work on the defenses of Pennsylvania, as well the organization and outfiting of troops. Throughout the tumultuous year of 1776, the Council of Safety proved to be the only government body capable of effectively responding to the demands of the war, thanks in no small part to the efforts of Rittenhouse .
When the Assembly met in first weeks of 1777, financial difficulties were at the forefront of debate, and on January 14, Rittenhouse was unanimously selected as state treasurer, and took office on January 18. Rittenhouse came to office at a time when few Pennsylvanians felt compelled to pay taxes. He would consistently wrestle with the inability to collect what was owed to the Commonwealth and would struggle to balance Pennsylvania's finances for many years to come. Rittenhouse would serve as state treasurer until 1789, but even after taking responsibility for the Commonwealth's finances, Rittenhouse maintained his position on the Council of Safety. In 1777, when the Supreme Executive Council of Pennsylvania abolished the Council of Safety and created a Board of War in its stead, Rittenhouse was appointed to the Board. In addition to the procurement and supply duties of the Council the Board interviewed suspected Loyalists, forcing those brought before them to take an oath of allegiance or face imprisonment.
When the British occupied Philadelphia in September of 1777, Rittenhouse and the other members of the government fled the city, with Rittenhouse eventually taking refuge in Lancaster. When the British evacuated the city in June of the following year, Rittenhouse returned to Philadelphia and resumed his governmental duties, both at the treasury and on the newly reconstituted Council of Safety. With the threat of British aggression against Philadelphia fading, Rittenhouse turned his attention to work outside of the government. Although Rittenhouse was on the Board of Trustees of the University of Pennsylvania in 1779, and was awarded a professorship in astronomy in 1780, academics was not a major part of his life. Prior to the end of the Revolution, Rittenhouse was selected to survey the banks of the Susquehanna River to determine the best location for a new town, concluding that the best location for a town was at Harris's Ferry. Based upon their recommendations, the town of Harrisburg was incorporated on the banks of the Susquehanna, and would subsequently become Pennsylvania's capital.
Following the Treaty of Paris of 1783, Rittenhouse again became involved in surveying the boundaries of Pennsylvania. In 1784, Rittenhouse was called upon to survey and establish the western boundary of Pennsylvania five degrees of longitude west of the Delaware River. Astoundingly, Rittenhouse's projections proved to be accurate to within 23 feet of modern measurements. After the establishment of the western boundary, Rittenhouse was responsible, along with surveyor Andrew Ellicott, for the completion of the final twenty miles of the Mason-Dixon survey in 1784, fixing the southern boundary of Pennsylvania with state of Delaware. In 1785, Rittenhouse undertook his final major surveying project, when he assisted in establishing the boundary between New York and Massachusetts.
Starting in the late 1780s, Rittenhouse began to publish works outside of astronomy and surveying, including works on magnetism (1786) and mathematics (1793 and 1795). On January 1, 1791, Rittenhouse became the second president of the American Philosophical Society, replacing the late Benjamin Franklin, a position he would hold until his death.
On April 14, 1792, President George Washington appointed Rittenhouse the first director of the United States Mint. While Rittenhouse protested his appointment, citing poor health, he accepted the position on July 1, immediately delving into the business of obtaining the men, materials and buildings the Mint would require. President Washington and Secretary of State Thomas Jefferson wholly and enthusiastically supported Rittenhouse's efforts and by 1794 production at the Mint reached a million copper cents and half-cents, up from 255,900 pieces the year before.
The Mint soon ran into difficulties, however, as the cost of copper became excessive, and by 1795, it cost several cents to mint a one cent coin. Beginning in 1794, the House of Representatives opened an investigation of the Mint, citing the disproportionate cost of minting coins, as well as charges that coinage was failing to reach the distant parts of the country and, therefore, only benefitted the Philadelphia region. By the conclusion of the investigation, however, Rittenhouse was exonerated of all wrongdoing. Rittenhouse, again citing his poor health, resigned from the mint on June 30, 1795.
Coincidentally with his resignation from the Mint, Rittenhouse became the second of two Americans elected to the Royal Society between the end of the Revolution and 1800. While he intended his retirement to free up time for scientific pursuits, Rittenhouse's health proved uncooperative. On June 22 1796, Rittenhouse was struck with fever and stomach pain, diagnosed by his nephew, Benjamin Smith Barton, as cholera. His condition steadily worsened and in the early morning hours of the 26th, Rittenhouse died. His body was interred under the floor of the observatory of his Norriton farm. The American Philosophical Society arranged a memorial service for Rittenhouse, at Philadelphia, on December 17, 1796, which was attended by George and Martha Washington, among many other dignitaries. Society member Benjamin Rush delivered the eulogy. John Adams provided perhaps the best summation of Rittenhouse's accomplishments in an 1818 letter to Thomas Jefferson when he wrote, "Rittenhouse was a virtuous and amiable man, an exquisite mechanician, master of the astronomy known in his time, an expert mathematician, a patient calculator of numbers."
Works Referenced:
Ford, Edward. David Rittenhouse: Astronomer-Patriot 1732-1796. Philadelphia, PA: University of Pennsylvania Press, 1946. Hindle, Brooke. David Rittenhouse. Princeton, NJ: Princeton University Press, 1964.
