290 CARNEGIE INSTITUTION OF WASHINGTON. 



tainment of the causes of the changes in the Earth's magnetism, which 

 in a comparatively few years suffice to produce noticeable alterations 

 and to vitiate the utility of mariners' charts, if not corrected, is believed 

 by many to be of the highest importance in our studies of the past and 

 future history of the Earth. The value of accurate magnetic data can 

 jirobably not be fully estimated at present, but will increase with lapse 

 of time. 



MAGNETIC SURVEY OF LAND AREAS. 



Naturally the war has interfered with the steady progress of the 

 magnetic surveys of certain regions under the jurisdiction of European 

 countries. The work accomplished during the period November 1, 

 1915, to October 31, 1916, may be summarized as follows: 



1. Extensive trips in Northern China, Mongolia, and Manchuria, under 



the direction of Dr. C. K. Edmunds, assisted by Observer F, Brown. 



2. Trips by Observer W. C. Parkinson to British New Guinea and out- 



lying islands of Australasia, and in the interior of New Zealand and 

 Australia. (See also observations under Magnetic Observatory 

 Work.) 



3. Interior trips by Observer H. E. Sawyer in French Kongo and Belgian 



Kongo, as also magnetic observations at some stations en route 

 from Durban, Africa, to Boma, Belgian Kongo. 



4. Magnetic observations at 13 stations on the island of Tahiti and in 



Califoi-nia by Observer H. F. Johnston. 



5. Magnetic obsei-vations by Observers D. M. Wise and A. Sterling in 



the northwestern part of South America. 



MAGNETIC OBSERVATORY WORK. 



Upon the completion of Observer Parkinson's work in New Zealand 

 in May 191G, he was assigned to Southwestern Austraha to examine 

 sites for one of the proposed magnetic observatories mentioned in the 

 report of last year. In connection with these examinations, magnetic 

 observations were made at various stations. In the meanwhile the 

 building plans for the observatory were prepared at Washington by 

 the Cliief of the Observatory Division, Mr. J. A. Fleming, who was 

 assisted by Magnetician W. F. WalHs. The latter left Washington for 

 Austraha in July 1916 to take charge of the erection of the observatory 

 buildings and the installation and operation of the instruments. The 

 site chosen is located near Marchagee, about 150 miles north of Perth, 

 Australia. Mr. Wallis is being assisted in the work by Mr. Parkinson. 



In September 1916, Observer D. M. Wise left Washington for 

 South America to instruct Observer A. Sterling in magnetic-survey 

 work, and especially to examine into the suitability of localities in 

 Peru for a second magnetic observatory, to be established, if possible, 

 in 1917. 



