866 GEORGE DAVIDSON. 



GEORGE DAVIDSON (1825-1911) 



Fellow in Class I, Section 1, 18S7. 



George Davidson was born in Nottingham, England, on May 9, 

 1825. Coming to the United States when a boy, he completed the 

 course of study in the Central High School, Philadelphia, in 1845. 

 He entered the service of the United States Coast Survey on June 1, 

 1845, in Washington, as secretary to Superintendent Bache. He 

 served also as a computer and in other capacities. 



The needs of navigation for accurate knowledge of the Pacific coast- 

 line were recognized by the authorities in Washington shortly after 

 the territory of California was acquired from Mexico. The first 

 requirements were determinations of the latitudes and longitudes of 

 the prominent capes, head-lands and entrances to the harbors, hydro- 

 graphic surveys of the harbors, and topographic surveys of harbor 

 surroundings. Davidson was the oldest member and the leader of a 

 party of three sent to the Pacific Coast shortly after the discovery of 

 gold in California, for the purpose of starting the accurate work of 

 the Survey. The party arrived in the summer of 1850. With the 

 exception of five 3^ears, coinciding approximately with the Civil War, 

 Davidson's home was in San Francisco continuously until the date 

 of his death, December 2, 1911. 



Assistant Davidson's first observing station on the Pacific Coast, 

 in 1850, was located at Point Conception, the most prominent and 

 dangerous angle in the western coast-line of the United States. He 

 determined the latitude and longitude, the variation and dip of the 

 magnetic needle, and he reported upon the best location for the pro- 

 posed light-house in that neighborhood. In the next four years other 

 stations were occupied at prominent points on the coast between 

 Puget Sound and Monterey. Astronomic, magnetic, hydrographic 

 and topographic data which were accumulated with extraordinary 

 rapidity were woven by him into a report as early as 1855, and issued 

 as a guide to mariners. Davidson's Directory for the Pacific Coast, 

 issued in 1858, was a remarkably accurate and comprehensive work, 

 embodying his own and other authentic data affecting maritime 

 interests on the coast. 



The construction of the Union and Central Pacific Railways and 

 the establishing of telegraphic connection between the Atlantic and 

 Pacific Coasts enabled the longitude determinations on the Pacific 

 Coast to be placed upon an accurate basis. The Pacific end of the 

 longitude time comparisons with Harvard College Observatory was 



