Background
Jared Mansfield was born on May 23, 1759 in New Haven, Connecticut. He was the son of Stephen Mansfield, a sea captain, and Hannah (Beach) Mansfield. He was a descendant of Richard and Gillian Mansfield who settled in New Haven in 1639.
investigator mathematician surveyor
Jared Mansfield was born on May 23, 1759 in New Haven, Connecticut. He was the son of Stephen Mansfield, a sea captain, and Hannah (Beach) Mansfield. He was a descendant of Richard and Gillian Mansfield who settled in New Haven in 1639.
Having entered Yale with the class of 1777 he was expelled in his senior year for various "discreditable escapades" (Dexter, post), but later regained the esteem of the college, receiving the degree of A. M. in 1787 and being enrolled with his class. In 1825 Yale conferred the honorary degree of LL. D. upon him.
In 1786 he became rector of the Hopkins Grammar School, New Haven, resigning in April 1790 because of "brighter prospects" elsewhere. These did not materialize, however, and he soon returned to his former position, in which he remained until 1795. After teaching for a few months in the Friends' Academy, Philadelphia, he was connected with an advanced school for both sexes in New Haven until 1802. From 1802 to 1803 he was acting professor of mathematics in the Military Academy, West Point, but in the latter year he was appointed surveyor general of the United States, with the rank of lieutenant-colonel, to survey Ohio and the Northwest Territory. Until he resigned his office he lived at Marietta (1803 - 05) and at Cincinnati (1805 - 12). In 1812 he was appointed professor of natural and experimental philosophy at West Point, but because of the war he was detailed to superintend fortifications at New London and Stonington, Connecticut In 1814 he resumed his teaching at West Point and continued there until 1828, when he resigned and went to live in Cincinnati. He died while on a visit to New Haven and was buried in Grove Street Cemetery.
Among his published papers are: "A Calculation of the Orbit of the Comet which Lately Appeared, " "On the Figure of the Earth, " and "Observations on the Duplication of the Cube and the Trisection of an Angle, " all of which were printed in Memoirs of the Connecticut Academy of Arts and Sciences; and "On Vanishing Fractions, " printed in the Transactions of the American Philosophical Society.
While in the New Haven school he wrote his Essays, Mathematical and Physical (1801), which is considered to be the first book of original mathematical researches by a native American. The essays deal with problems in algebra, geometry, fluxions (calculus), and with nautical astronomy, giving practical methods of finding time, latitude, and longitude from observations at sea. A chapter on gunnery deals with fundamental problems of ballistics, and in it the importance of airresistance is pointed out, not only as a retarding force (which is considered in the light of our modern molecular theory of matter), but also in its effect on the projectile. That effect, he showed, is a deviation of the projectile from its due course--what is known today as the gyroscopic phenomenon. Prior to his book, projectiles were treated without consideration of the effect of the medium through which they passed.
On March 2, 1800, he married Elizabeth, daughter of David and Mary (English) Phipps. Edward Deering Mansfield was his son.