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G.W. Dean—Longitude Determination across the Continent, 441 
Art. LVI.—Longitude Determination across the Continent ; by 
GrorGe W. Dean. (Read before the American Association 
at Indianapolis.) 
Wirn the permission of Professor Peirce, Superintendent of 
the United States Coast Survey, I offer to the Association a 
brief statement, in regard to the method used, and the results 
obtained, by the Coast Survey, in determining the longitude of 
San Francisco and several intermediate points, by telegraphic 
exchange of clock signals, with Harvard College Observatory, 
Cambridge, Massachusetts. 
required for transmitting a 0m through one or more of those 
instruments. The results of those preliminary experiments were 
longitude operations at Cambri ge. : 
The biden acid for determining the clock and instrumental 
Corrections at Cambridge, were made chiefly by Assistant A. 
T. Mosman and Sub-Assistant F. Blake, Jr. 
