U. &. COAST AND GEODETIC SURVEY — ROBERTS 231 



the establishment of coordinate systems designed to bring the benefits 

 of geodetic control to all surveyors. He was also the architect of 

 the existing 1927 North American geodetic datum, which resulted 

 from one of the greatest mathematical feats of general adjustment 

 in the history of geodesy. 



Benjamin Peirce, one of the foremost mathematicians of the country 

 and also a Superintendent of the Survey, employed his son Charles, 

 who worked several years before going on to become a world-famous 

 philosopher and author of the theory of pragmatism. Bureau mathe- 

 maticians, trained to recognize faultless observations, were called 

 on to examine the questioned North Pole observations of former 

 Survey draftsman Eobert Peary. These, as the world knows, were 

 found beyond possibility of falsification, closing the controversy 

 by a simple demonstration of the truth, and paving the way to his 

 receiving the rank of Rear Admiral from a grateful Congress. 



Later officers have served as special experts and adjudicators in 

 numerous trials over riparian rights, waterfront land grants, and 

 other beach problems. Some such cases have involved millions of 

 dollars, and one concerned the actual ownership of parts of the naval 

 base at Mare Island. Today such special knowledge is in demand 

 in cases of offshore rights involving the troublesome problems and 

 definitions of seaward boundaries. 



Plans initiated by Hassler and carried forward by Bache and his 

 successors to investigate the elusive and little-understood magnetic 

 forces that actuate the compass needle have led the Survey to the 

 operation of several fixed observatories, where instruments of great 

 sensitivity make continuous recordings of the fluctuating magnet- 

 ism. They provide the magnetic information necessary to the use of 

 magnetic compasses in navigation, thus serving all ships and aircraft. 

 They help monitor radio communication conditions, use of radio 

 navigational aids, and the prediction of radio fadeouts. They pro- 

 vide basic information for the interpretation of magnetic prospecting 

 surveys made in the search for oil and minerals, as well as for the 

 use of military implements. 



The first isogonic chart was published in 1855, partly as a result 

 of the use of a magnetometer of Bache's design. The Survey has 

 now been legally designated as the nation's collection agency and 

 repository for world magnetic data, and it compiles all American- 

 issue magnetic charts, including world charts prepared for publica- 

 tion by the Hydrographic Office. 



Experience in the exacting task of operating magnetic observ- 

 atories led to an assignment of like nature in 1925, when the respon- 

 sibility for seismological investigations was added. This called for 

 similar skills and took advantage of the existence of the observa- 



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