280 CARNEGIE INSTITUTION OF WASHINGTON. 



fact, it has been possible to have but one land party continuously in 

 the field, namely, that under the charge of Observer Frederick Brown. 



During the year Mr. Brown has been at work in Central Africa. He 

 successfully completed magnetic-exploratory expeditions through 

 Cameroon to Lake Tchad, French Equatorial Africa, as also through 

 Angola and British Central Africa to Portuguese East Africa and Mad- 

 agascar. Besides obtaining new magnetic data, he has been able to 

 reoccupy some of our former stations in Africa, thereby securing data 

 for determining the secular changes in the Earth's magnetism. 



As heretofore, the Carnegie observers, in addition to the ocean mag- 

 netic work, have obtained valuable magnetic data at the vessel's ports 

 of call. 



Captain Roald Amundsen, with instruments loaned him by the De- 

 partment, secured during his Arctic expedition a series of magnetic 

 observations in 1918-1920 at his winter quarters and at about 40 points 

 along the Siberian Coast. The original records of this work, which were 

 to have been forwarded by way of Dickson Island, have unfortunately 

 been lost on the coast of Siberia, but copies of essential parts have 

 been received by way of Nome, Alaska. In accordance with Captain 

 Amundsen's aerogram request, received in March 1920 through the 

 United States Navy Department, the Department sent him addi- 

 tional equipment to Nome, where he arrived at the end of July, leav- 

 ing for the Arctic about two weeks later. 



Some magnetic data for Austraha have been received from the Gov- 

 ernment Astronomer G. F. Dodwell of the Adelaide Observatory and 

 Professor Kerr Grant; the observations were made in part with in- 

 struments loaned by the Department and in accordance with our 

 methods. Also, some further magnetic data pertaining to the solar 

 eclipse of Maj^ 29, 1919, have been received from various cooperating 

 institutions. 



The chief of the Magnetic Survey Division, Mr. Fleming, made an 

 inspection trip to the Carnegie while at Buenos Aires, and after visiting 

 various institutions in Brazil and Argentina, he inspected the progress 

 of the magnetic observatory buildings being erected under Dr. Ed- 

 monds's direction. (For further details, see pp. 293-295.) 



It may not be without interest to record here, for a sununary of the 

 land work, that during 1905 to 1920 the observers of the Department 

 have made magnetic observations at about 4,000 stations in all parts of 

 the Earth, at about 10 per cent of which observations were repeated at 

 various intervals of years in order to determine the magnetic changes. 

 The stations are, on the average, 75 miles apart and are distributed 

 over 121 different countries in Africa, Asia, Australasia, Europe, North 

 America, South America, Arctic and Antarctic regions, and islands 

 of the Atlantic, Pacific, and Indian Oceans. Over 1,000,000 miles 



