DEPARTMENT OF TERRESTRIAL MAGNETISM. 317 



take up land-survey work in Africa. During December he occupied 

 stations at New Brighton and Cass, and made intercomparison obser- 

 vations at the Christchurch Magnetic Observatory, New Zealand. 

 Mr. Sawyer took a short vacation between December 25, 1915, and 

 January 5, 1916, and then sailed on January 6 from WeUington for 

 Sydney, Austraha. At Sydney he secured at the Red Hill Observa- 

 tory an intercomparison of instruments with those of Observer W. C. 

 Parkinson. On February 19, Mr. Sawyer had completed all arrange- 

 ments necessary at Sydney and sailed for Durban, South Africa (see 

 page 314). 



SOUTH AMERICA. 



On September 30, 1916, Observers D. M. Wise and A. Sterling left 

 New York bound for South America via the Panama Canal. After re- 

 occupying, en route, our magnetic stations at Havana and Colon, 

 the party made magnetic observations at various stations in Ecuador. 

 The purpose of this trip, in addition to securing magnetic observations 

 at points in various countries of South America, is to determine a 

 suitable location for a magnetic observatory. The party is in charge 

 of Mr. Wise. 



MISCELLANEOUS WORK. 



On May 17, 1916, Observer H. F. Johnston was relieved of ocean 

 work aboard the Carnegie at Lyttelton, New Zealand. He proceeded 

 to the island of Tahiti, where he made the observations required 

 for the examination of the island as to a suitable site for a possible 

 magnetic observatory ; magnetic observations were made at 10 stations 

 on the island of Tahiti and on the outlying coral islets. The region 

 was found, in general, to be subject to local magnetic disturbance. 

 Mr. Johnston sailed for San Francisco on July 2, 1916, and on arrival 

 there reoccupied the magnetic stations of the Department at Goat 

 Island and San Rafael, as also at San Diego. He reported at the 

 office in Washington on August 7, 1916. 



Special attention has been paid during the past year to securing 

 additional comparisons between the magnetic standards of various 

 services and ours and to the adequate control of instrumental con- 

 stants. Besides frequent intercomparisons of our own instruments, 

 both at Washington and in the field, the following comparisons with 

 the standards of foreign observatories have been obtained since August 

 1915: (1) In Great Britain by E. Kidson, at Kew, Greenwich, Stony- 

 hurst, and Eskdalemuir, August to October 1915; (2) at Washington 

 during November and December 1915, with the standards of the 

 Dominion Astronomical Observatory of Canada (Observer C. A. 

 French) and with those of the Canadian Meteorological Service 

 (Observer W. E. W. Jackson) ; (3) at Christchurch Magnetic Obser- 

 vatory by the Carnegie observing party in November 1915, and again 

 in April-May 1916. 



