CHRONOMETRIC CONNECTIONS. 37 



unfortunately blown to the southward by a cold northerly gale, which caused 

 a fall of temperature in the chronometer boxes to the extent of 15 Fahrenheit, 

 and lengthened the voyage seven or eight days, the Reindeer being unable 

 to steam against the wind and sea. 



Table XIX. shows the average rates of the chronometers before and after 

 the voyage, the mean of them, which are the adopted travelling rates, and the 

 difference of longitude between the stations as derived from each chronometer. 



84. On the arrival of H.M.S. Reindeer at the U.S. Navy Yard, Mare Island, 

 the members of the Expedition were courteously received by Commodore 

 PHELPS, U.S.N., the Commandant of the Navy Yard, and all possible assistance 

 was rendered. The circle observations were taken on the summit of an 

 elevation in the Navy Yard, on which stood a small observatory, and near it 

 an inscribed stone on which the mercury trough was placed. This stone was 

 connected with the triangulation of the coast survey by Professor GEORGE 

 DAVIDSON who, by permission of the Superintendent, kindly supplies the 

 information regarding the longitude of the station. 



85. The longitude of a station in "Washington Square, San Francisco, from 

 the Washington Observatory, D.C., was determined by elaborate telegraphic 

 signals in the year 1869 (U.S. Coast Survey Report, 1870). The inscribed 

 stone on the hill in the Navy Yard was connected with the triangulation of 

 San Francisco Harbour, and thus it was found to be in 



Latitude 38. 5'. 53"' i North. 



Longitude 8 h . 9. 5 s ' 08 West of Greenwich. 



86. The mean difference of longitude between Honolulu and the Navy Yard 

 as given by the chronometers, rejecting only Q, S, and KH, on account of 

 their small size and previous erratic movements, is 



2 h . 22 m . 28 S> 19 3 8 -o., 



whence the longitude of Honolulu appears to be 



io h . 3i m . 33"-2 3 9- o., West from Greenwich, 

 a determination to which I can attribute but little value. 



G. L. TUPMAN. 



F 2 



