dl:partme;nt oi^ terrestrial magnetism. 165 



delay of some two weeks was incurred by the necessary repairs, chiefly of the 

 rudder. The land and sea work being completed at this port, the Galilee en- 

 tered on the last and final leg of her cruises, setting sail on April 5 for lati- 

 tude 1.5° south and longitude 114° west, whence a north course was fol- 

 lowed to latitude 12° north. From this position the track followed was al- 

 most a direct one to about 31° north latitude in 137.5° west longitude, from 

 which point course was set for the Golden Gate. San Francisco was reached 

 on May 21, 1908, thus concluding Cruise III, begun at San Diego on Decem- 

 ber 22, 1906, and having a total length of about 35,000 nautical miles. The 

 necessary swings and land observations for properly closing the work having 

 been made, the vessel was returned to her owners on June 5, 1908, and the 

 various instruments and appurtenances forwarded to the office at Washington. 



Cruise III thus exceeded in length the combined total (26,000 nautical 

 miles) of Cruises I and II. Twelve harbors were visited; at all of these ex- 

 tensive shore observations and intercomparisons of ship and land instruments 

 were made; in three of the harbors swinging ship could not be done, either 

 by reason of lack of tug facilities or of insufficient depth of water. Twenty 

 primary land stations at the following points were established: Coronado 

 Beach Island, San Diego, California, U. S. A. ; Nuka Hiva Island, Mar- 

 quesas Islands (2 stations) ; Papeete, Tahiti Island, Society Islands; Mota 

 Uta Island, Papeete Harbor, Society Islands ; small coral island in Papeete 

 Harbor, Society Islands ; Apia INlagnetic Observatory, Samoan Islands ; Tar- 

 rang Island, Tomil Bay (Yap Island), Caroline Islands; Zi-ka-wei Magnetic 

 Observatory, Shanghai, China; Woosung, China (2 stations); Sitka Mag- 

 netic Observatory, Alaska; Kutkan Island, Sitka Harbor, Alaska; Honolulu 

 Magnetic Observatory, Hawaiian Islands; Jaluit, Marshall Islands; Christ- 

 church Magnetic Observatory, South Island, New Zealand; New Brighton 

 Beach, South Island, New Zealand; San Lorenzo Island, Callao Bay, Peru; 

 Goat Island, San Francisco Bay, California, U. S. A., and San Rafael, Cal- 

 ifornia, U. S. A. 



In addition to these primary stations, there were established in the neigh- 

 borhood of the same in all 20 secondary stations for the purposes of inter- 

 comparison and standardization of ship's instruments. Swings for the deter- 

 mination of ship's constants and deviation factors were made at the following 

 harbors : San Diego Bay, Papeete Harbor, mouth of the Yangtse River, Sitka 

 Harbor, Pearl Harbor (off Honolulu Magnetic Observatory), Jaluit Lagoon, 

 off New Brighton Beach, Callao Bay, and San Francisco Bay. At these 

 points 13 complete swings (both port and starboard helms) on 8 points were 

 made, each involving complete observations of the three magnetic elements. 



While at sea during Cruise III in addition to the course observations, 

 which were made as frequently as weather and sea conditions permitted, 

 swings, under sail, covering 6 to 8 points, were carried out as follows : 21 for 



