Among the early makers of mathematical instruments in Phila- 

 delphia was William Dean (P-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, ISji inches 

 in length, and with a 5-inch needle. The dial is marked "dean 

 PHiLAD ^." 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 L 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 evi- 

 dence 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 



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