Among the early makers of mathematical instruments in Philadelphia was William Dean (?-1797), who is believed to have been working in that city as early as 1778. His name first appears in local directories in June 1792, where his shop address was listed as No. 43 South Front Street. Later he advertised that he made and sold "Surveying instruments—Telescopes, Sextants, Quadrants—and every article requisite for navigation, surveying, levelling,& c...."

According to details which were noted in his last will, which was dated June 1, 1797, and filed and proved in the following month, Dean's death appears to have been preceded by a long illness. He designated his two sisters as his executrices, and the fact that his will specified the appointment of a Mr. Thomas Yardley, Jr., as guardian of his three children indicates that he may have been a widower at the time of his death.

A surveying compass by this maker was recently brought to light in, the Clark County Historical Society, Springfield, Ohio, by Dr. Donald A. Hutzlar of the Ohio State Museum. The instrument is a plain compass in brass without levels, 13-1/2 inches in length, and with a 5-inch needle. The dial is marked "DEAN PHILADa." The wooden cover for the instrument is marked with the names of previous owners and dates, as follows:

Jno. C. Symes, Aug. 10, 1778 I. Ludlow, 1791 Henry Donnel, July 24, 1794 Jonathan Donnel, 1796 John Dyherty Thomas J. Kizer, 1838 David J. Kizer, '78.

A description of this instrument in "The History of Clark County, Ohio" by A. P. Steele, published in 1881 by the W. H. Beers Co. of Chicago, adds considerably to its interest as a historical record of American scientific instruments and their use: "Col. Thomas Kizer, the veteran surveyor, has in his possession a compass made by Dean of Philadelphia; this instrument was owned and used by his father, David Kizer, who obtained it from John Dougherty about 1813; Dougherty got it from Jonathan Donnel. This relic is marked I. Ludlow, 1791; Henry Donnel, 1794; J. Donnel, 1796, John Dougherty, 1799; these marks are rudely scratched upon the cover of the instrument, and bear every evidence of being genuine; there is no doubt but that this old compass was used in making the first surveys in this county, or that it[Pg 61]is the identical instrument used by John Dougherty, in laying off Demint's first plat of Springfield, and by Jonathan Donnel on the survey of 'New Boston.'" It is to be noted that some discrepancies exist in the listing of names and dates of the previous owners between Steele's History and those which actually appear on the cover of the instrument. Steele apparently made the changes he deemed necessary in his account of the instrument.

WILLIAM DEAN, a Mathematical Instrument Maker, "Informs the public he has commenced business at 43 South Front Street, directly opposite the Post Office;" so says his advertisement in Dunlap's American Daily Advertiser of June 4, 1792. By a later announcement we read that he "makes and sells Surveying instruments— Telescopes, Sextants, Quadrants,—and every article requisite for navigation, surveying, leveling &c." Dean's shop was on the East side of Front street, the fourth house North of Chestnut, and his advertisement indicates where the Post Office was during that year. Eight years later the directory tells us the Post Office was at 27 South Third Street. We learn from the early directories that 43 South Front Street was also occupied by Michael Davenport, Cooper, from 1791 to 1795 and from 1797 to 1801 by Widow Davenport. William Davenport, Mathematical Instrument Maker, is listed from the same address from 1802 to 1804, and we may assume that he was a son of Michael, the Cooper, and was an apprentice of William Dean (who advertised from this address as late as January 3, 1794) and carried on Dean's business at his parents' house. Davenport's shop is given in the directories of 1805 to 1814 as 45 South Front Street, which may have been a renumbering of the houses; while from 1816 to 1820 his address is given as No. 25 South Front Street. Unfortunately no specimen of their instruments is known in Philadelphia, but in the Peabody Museum of Salem, Massachusetts is a brass surveyor's compass marked "Wm. Davenport, Maker, Philada." and undated.

Natural History Museum