DEPARTMENT OF TERRESTRIAL MAGNETISM. 317 



DETAILS OF OBSERVATIONAL WORK. 

 OCEAN-SURVEY WORK.i 



The Carnegie continued the ocean-survey work throughout the 

 year. On November 1, 1920, she was at Lyttelton, New Zealand. 

 The series of comparisons between the standard instruments of the 

 Christchurch Observatory and those of the Carnegie were satisfactorily 

 completed early in November; Mr. H. F. Skey, director of the Observa- 

 tory, extended every courtesy and facility for this work and took an 

 active part in the observations. The Carnegie was towed out to sea 

 November 19 and proceeded under her own power until after clearing 

 Banks Peninsula, when all sails were set. For 3 days the wind blew 

 from the north, then shifted to the west and remained westerly for 4 

 days. The 180th meridian of longitude was crossed on November 22, 

 and the date November 22 was repeated. 



No heavy storms were met, but moderate gales blew on November 

 22, November 27, December 1, and December 5. From December 1 to 

 December 10 the wind blew steadily from the northwest, driving the 

 vessel about 600 miles east of her course. On December 14, on enter- 

 ing the southeast trade-wind, course was set for Papeete, which was 

 reached November 23. 



The total distance sailed from Port Lyttelton to Papeete was 4,262 

 miles, which gives a daily average of 122 miles for the 35 days at sea. 

 Magnetic observations were obtained at 54 stations for declination 

 and at 33 stations for inclination and horizontal intensity. Complete 

 determinations of the 5 atmospheric-electric elements (potential 

 gradient, conductivity, ionic numbers, penetrating radiation, and radio- 

 active content) were made on 9 days; 4 elements were observed on 13 

 days; and three 24-hour series of diurnal-variation observations for 

 the first three elements named were made. 



Shore observations to obtain secular-variation data were made at 

 the Department's station of 1916 at Point Fareute. Some special 

 work was also done in connection with the atmospheric-electric instru- 

 ments. 



The Carnegie left Papeete Harbor on the afternoon of January 3, 

 1921, in the midst of a heavy tropical rain squall. Fortunately, the 

 wind held more from the east than from the north during the entire run 

 from Papeete, so that Fanning Island was sighted at 10 o'clock on the 

 morning of January 14 from a good bearing, after being hove to 60 

 miles east of the island during the previous night. The vessel arrived 

 off Whaler's Anchorage at 1^ 25°^ p. m., and after tacking back and 

 forth for 2% hours, during which time cablegrams were despatched, 

 departure was taken for San Francisco. The old Galilee station is no 

 longer available on account of the extension of buildings and electric 



^From Commander J. P. Ault's reports. 



