David Rittenhouse (April 8, 1732 - June 26, 1796) was the first director of the United States Mint from 1792 to 1795. However, he was also noted for being an important surveyor of colonial (and later, state) boundaries, and for being one of the finest scientific instrument-makers in Colonial America. His work included the construction of many surveying and astronomical instruments, including clocks, telescopes, and orreries. The eagerness with which Rittenhouse tackled his interests was astonishing: though he did many great things and became well-respected as a scientist and engineer, he was entirely self-taught. Rittenhouse may rightly be called one of the few great scientists of Colonial America, second only to Benjamin Franklin.

The Rittenhouse family

David was the great-grandson of William Rittenhouse, a Dutch Mennonite who immigrated to the Americas in 1687 and settled near modern-day Germantown, Pennsylvania. The elder Rittenhouse founded the first paper mills in the Americas, and the industrious family became a prominent one in the colony of Pennsylvania. William's children would continue the family business after William's death in 1708, though several would branch out into other fields including preaching in the Mennonite Church, and farming. But one family scion was destined for even greater things.

The young engineer

In his early life, David Rittenhouse seemed destined to become a farmer like his father, Matthias. However, David received several books on mathematics and geometry along with a chest of tools from the estate of an uncle, and the young boy put these to intense use. When he turned 18, he established a clock and instrument making business in Norriton (probably modern Norristown), a trade he shared with his younger brother Benjamin Rittenhouse. With his new trade, he continued his studies of mathematics and geometry; at one point, he worked out the rudiments of calculus on his own, not realizing that these same methods had been worked out half a century prior. (Though chagrined to find he wasn't the first, he soon devoured a translation of Newton's Principia). He also began studying astronomy and surveying, and he would soon make noteworthy contributions in both fields.


One of his most important tasks as a surveyor was his 1763-4 survey of the Delaware-Pennsylvania border, which entailed drawing a 12-mile circle about the Court House in New Castle, Delaware (which is why the northern border of the state of Delaware is curved). Rittenhouse's work was so precise and well-documented that it was incorporated without modification into Charles Mason and Jeremiah Dixon's survey of the Pennsylvania-Maryland border. Later Rittenhouse would help establish the boundaries of several other states and commonwealths both before and after Independence, including the boundaries between New Jersey, New York, and Pennsylvania. Though he was a fine surveyor by trade, he was a noted crafter of surveying instruments -- like compasses and sectors -- used by many surveyors throughout the colonies (including George Washington). He was also credited with several inventions and improvements to surveying equipment, including the addition of a declination arc to the surveyor's compass. However, his interest in instrumentation wasn't limited to surveying and clocks.

The scientist

Since Rittenhouse was an avid student of astronomy, he constructed several fine telescopes, highly-accurate clocks, and quadrants. In fact, he constructed several such instruments specifically to observe the June 3, 1769 transit of the planet Venus across the face of the Sun, a transit which he had himself calculated. He constructed the first true observatory in the colonies near Philadelphia for the transit, and convinced colonial authorities to establish other smaller observatories for this purpose -- it amounted to the first major astronomical "experiment" conducted in Colonial America. Following this, he continued building more clocks famed for their precision, and several orreries which sold for hundreds of pounds each. Rittenhouse's interest and work in astronomy would eventually lead to his appointment to a professorship in astronomy to the University of Pennsylvania from 1779 to 1782, and would contribute to his election to the presidency of the American Philosophical Society. His predecessor, Benjamin Franklin, died in office in 1791, and Rittenhouse himself was succeeded by Thomas Jefferson -- he was certainly in good company! He was made an honorary Fellow of The Royal Society in 1795 shortly before his death.

Rittenhouse as public servant

Rittenhouse's work as a public servant began in the 1770's, beginning with an attempt to make the Schuylkill River navigable in 1773. Later, during the Revolution, Rittenhouse served as an engineer for the "Committee of Safety" which was charged with various tasks including improvements in cannon and musket design and casting. Later, he would serve as Pennsylvania's Treasurer and Secretary of State. However, his most significant post was as the first director of the fledgling United States Mint, to which he was appointed by President George Washington in 1792. In this post, he oversaw the construction of the first Federal building in the United States, along with the Mint's first issuance of coins in 1793.

David Rittenhouse died in Philadelphia on June 26, 1796, and is buried in Laurel Hill Cemetery near the Schuylkill River. In 1825, the old "Southwest Square" in Philadelphia was renamed Rittenhouse Square in his honor.

Appleton's Cyclopedia of American Biography (Appleton and Co., 1887) from http://www.famousamericans.net/williamrittenhouse/
S.A. Bedini, Early American Scientific Instruments and Their Makers, Smithsonian Institution: United States National Museum Bulletin v.231, 1964