a copy of his Benjamin Banneker s Pennsylvania^ Delawarey Vir- 

 ginia And Maryland Almanac and Ephemeris For the Year of Our 

 Lord, 1792 to Thomas Jefferson, who was so impressed with it 

 that he forwarded it to the Marquis de Condorcet, secretary of the 

 French Academy of Sciences. After his work with Ellicott had 

 been completed, Banneker retired to his farm to produce almanacs 

 annually until 1802. When he died in 1806 he was eulogized before 

 the French Academy by the Marquis de Condorcet, and William 

 Pitt placed his name in the records of the English Parliament.'^ 



Joel Baily 



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.'^ 



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. 



'^ John H. B. Latrobe, "Memoir of Benjamin Banneker," Maryland Coloniza- 

 tion Journal (Baltimore, May 1845); Philip LePhillips, "The Negro, Benjamin 

 Benneker," Records oj the Columbia Historical Society (1916), vol. 20. 



'^ Arthur E. Tames, Chester County Clocks and Their Makers (West Chester, 

 Pa.: Chester Historical Society, 1947), pp. 29-39; Transactions of the American 

 Philosophical Society, ser. 1, vol. 1, pp. 85-97. 



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