Still another 18th-century practitioner was Joel Baily (1732-1797), a Quaker of West Bradford, Pennsylvania. In addition to his trade as a clockmaker and gunsmith, Baily achieved local eminence as an astronomer, mathematician, and surveyor.[12]

In 1764, at the time that Charles Mason and Jeremiah Dixon established their headquarters near his farm, Baily was the local surveyor. Obtaining employment with the expedition, he worked with Mason and Dixon until the completion of their survey in 1768. Baily was subsequently employed by Mason and Dixon to build pine frames for carrying the 20-foot rods to be used in the second measurement of courses from the Stargazers' Stone southward.

In 1769 Baily was appointed by the American Philosophical Society to work with Owen Biddle in setting up the station at Cape Henlopen for observation of the transit of Venus. In 1770 he again worked with Biddle in taking the courses and distances from the New Castle Court House to the State House Observatory in Philadelphia for determining the latitude and longitude of each. In the same year Baily was elected a member of the American Philosophical Society.

Reverend John Prince

Another noteworthy mathematical practitioner of the period was the Reverend John Prince (1751-1836) of Salem, Massachusetts. The son of a hatter and mechanic, Prince studied natural philosophy under John Winthrop at Harvard and received his B.A. degree in 1776. He was a student of divinity under Samuel Williams and was ordained in 1779 at the First Church in Salem. Although an amateur of the sciences, Prince became a skilled maker of scientific instruments. He made, sold, and repaired instruments for the use of numerous colleges, schools, and academies, including Brown, Dartmouth, Rutgers, Harvard, Union, Amherst, and Williams. Among other accomplishments, he effected "improvements" on the lucernal microscope and the air pump.[13]

Amasa Holcomb

Although he was born in the 18th century, Amasa Holcomb (1787-1875) properly belongs to a later period. An astronomer and telescope maker of Southwick, Massachusetts, Holcomb became a surveyor in 1808. An autobiographical sketch noted that "he manufactured about this time a good many sets of surveyors instruments—compasses, chains, scales, protractors and dividers, some for his pupils and some for others."[14]


Instruments of Metal