l62 REPORTS OF INVESTIGATIONS AND PROJECTS. 



vations at Auckland, New Zealand, securing comparisons of instruments at 

 the observatories at Melbourne and Sydney, Australia, and by making the 

 final determination of constants at the Apia Magnetic Observatory with the 

 instrumental outfit courteously loaned by the latter observatory. For this 

 additional courtesy and assistance rendered by the Apia Observatory the 

 Department is further indebted. Having returned in good condition to the 

 observatory the instruments loaned, he resumed his private surveying practice 

 at Suva, Fiji. 



Miscellaneous. — The Department cooperated with the expedition to the 

 Aleutian Islands under the direction of Prof. T. A. Jaggar, in charge of the 

 Department of Technology of the Massachusetts Institute of Technology. 

 Prof. H. V. Gummere, of the Drexel Institute of Philadelphia, a member of 

 this expedition, was given the required training in magnetic observations and 

 the constants were determined for the instruments to be used by him and 

 plan of work furnished him. 



Mr. R. B. Oliver, member of a special exploring expedition in the Kongo 

 Free State, was given the necessary training at the office to enable him to 

 obtain values of the magnetic declination with the compass attached to his 

 surveyor's transit. He was furthermore acquainted with the work done by 

 various previous expeditions under the auspices of the Belgian Government, 

 and informed where secular variation data are desired. 



The land magnetic survey zvork executed thus far may be briefly sum- 

 marised as follows: 



The three magnetic elements have been determined at 301 primary sta- 

 tions, distributed over the following countries: Africa (i), North America 

 (197), South America (i), Asia (6y), Bermuda (5), Australasia (4), 

 Pacific Islands (25). At about 70 of these stations observations exist for 

 previous periods, hence the reoccupation of these by the Department has 

 furnished valuable secular variation data. Special investigations have also 

 been made in locally distributed regions in which observations were secured 

 at a number of additional secondary stations, e. g., at Tread well Point (about 

 25) and in the Bermuda Islands (about 6y) ; consequently, in addition to the 

 observations at the above 301 primary points, approximate determinations 

 were made at about 100 secondary stations. 



Intercomparisons of instruments have been secured at the following mag- 

 netic observatories: Apia (Samoan Islands), Baldwin (Kansas), Chelten- 

 ham (Maryland), Christchurch (New Zealand), Cuajimalpa (Mexico), 

 Havana (Cuba), Hongkong (China), Honolulu (Hawaiian Islands), Mel- 

 bourne (Australia), Shanghai-Zi-ka-wei (China), Sitka (Alaska), Sydney 

 (Australia), Tokyo (Japan), Toronto-Agincourt (Canada), Vieques (Porto 

 Rico). 



