George Davidson (1825 – 1911)
	
George Davidson was born in Nottingham, England. His family moved to the United States in 1832 and settled in Pennsylvania. After graduating high school, he worked as a clerk to the superintendent of the United States Coast Survey. He did geodetic field work in several states on the east coast from 1846 to 1850. He went to California in 1850 with the Coast Survey and spent several years determining the latitude and longitude of prominent features and reporting on the proper locations for lighthouses. He surveyed Washington and Puget sounds, triangulated the San Francisco coastal region and named a number of mountains in the Olympic range. He was on the Atlantic seaboard from 1861 to 1867 engaged in engineering work on coast and river defences, commanding the steamer //Vixen// for a time, and did astronomical work along the coast. In 1866 he was chief engineer on an expedition to survey a ship canal across the Isthmus of Darien. In 1867 he made an examination and report on the geography and resources of Alaska, pending its purchase. His reports and recommendation influenced the passage of the bill. In 1867 he was placed in charge of the Coast Survey on the west coast, doing triangulation and astronomical work, and his results were better than ever had been recorded. In 1869, he observed a total eclipse of the sun under the 60th parallel.((“George Davidson (geographer).” //Wikipedia,// 2019 website: https://en.wikipedia.org/wiki/George_Davidson_(geographer) ))
	

In Alaska, Davidson developed a friendship with Kohklux, a Tlingit clan leader, and his two wives, sisters from the Stikine River Tlingits. Kohklux and his wives drew a map for Davidson that depicted the route inland from the coast to an old Hudson’s Bay Co. trading post site at Fort Selkirk. Davidson wrote place names on the map, using English to approximate the names in Hän, Tutchone, and other Athapaskan languages. The map and Davidson’s second-hand knowledge of the interior land helped later cartographers.((John Cloud, “The Tlingit Map of 1869, a masterwork of indigenous cartography.” //Expedition,// Volume 54, number 3: 10-18. Pdf on 2019 website: 
https://noaacoastsurvey.files.wordpress.com/2012/10/tlingitmapjohncloud1.pdf))

In 1881, Davidson measured the Yolo base line in California twice, the longest base line in trigonometrical operations to date. His system of triangulation was thereafter called Davidson quadrilaterals. He measured the Los Angeles base line three times in 1888/89. He retired from the Coast Survey in 1895 with fifty years of service. He had many noteworthy accomplishments over his career and held several academic positions. After his retirement he became the first professor of geography at the University of California, Berkeley, chaired the department from 1898 until his retirement in 1905, and remained an emeritus professor until his death. He was one of 182 charter members of the Sierra Club and served on the board from 1894 to 1910.((“George Davidson (geographer).” //Wikipedia,// 2019 website: https://en.wikipedia.org/wiki/George_Davidson_(geographer) ))