DEPARTMENT OF TERRESTRIAL MAGNETISM. 269 



3. Electric survey of Earth (begun 1907) : 



a. Land. 

 6. Ocean. 



c. Diurnal and other variations; effects during eclipses; etc. 



d. Observations in upper levels (electric disturbances; "statics"; etc.). 



e. Earth-currents (disturbances in telegraphic transmission). 

 /. Polar lights. 



4. Observatory work (terrestrial magnetism, atmospheric electricity, earth-currents, 



polar lights, etc.; present and desirable distribution of recording stations; magnetic 

 storms, perturbations, pulsations, relations with solar activity, etc.). The Department 

 of Terrestrial Magnetism has at present in operation two magnetic observatories: 

 Watheroo, Western Australia, and Huancayo, Peru. 



5. Magnetic observations in upper levels and ocean depths: 



a. Infinite distributions possible on basis of surface observations alone. 



b. Bearing on aviation problems. 



c. Local disturbances and variations. (See also 2/i.) 



6. Cosmic relations. 



a. Solar and planetary magnetism. 



b. Relations between solar activity, terrestrial magnetism, and terrestrial electricity. 



7. Laboratory investigations (magnetism in general; development of instruments and 

 methods for investigational and observational work; experimental reproduction of 

 observed cosmic magnetic and electric phenomena). 



8. Analysis and causes of the Earth's magnetic and electric fields: 



a. Results of previous analyses. 



b. Line-integrals. Is action on magnet wholly a couple? 



c. Role of the variations (analyses and causes). 



d. Possible bearings on the properties and constitution of matter, and cause of 

 gravitation. 



e. See 2h, 5a, and 5c. 



9. General aim of work as announced in 1903. "To investigate such problems of world- 

 wide interest as relate to the magnetic and electric condition of the Earth and its 

 atmosphere, not specifically the subject of inquiry of any one country, but of inter- 

 national concern and benefit." 



10. Funds and name of department. 



Although the conference was limited to one day, on account of other press- 

 ing engagements of some of the members, its main purposes were accomplished. 

 The Institution and the Department were fortunate in the selection of those 

 who had been invited to the conference. Suggestions and recommendations 

 were made which will prove beneficial in the future work of the Department 

 and serve as a further stimulus in our endeavors. Brief consideration was 

 given to the question of a more comprehensive or more elucidative name for 

 the Department than its present one, but no definite conclusion was reached. 



MAIN CONCLUSIONS AND RECOMMENDATIONS OF CONFERENCE.] 

 A. Magnetic and Electric Survey of the Earth: 



a. It was the consensus of opinion that the magnetic and electric survey of the 

 Earth should be continued; however, in view of the satisfactory progress made since 

 1905, the future work need not be so intensive, but should be planned so as to obtain 

 additional data in regions where urgently required, above all, as to the secular changes 

 of the Earth's magnetism, which may play an important role in the theoretical solution 

 of some of the outstanding problems. Detailed surveys of locally disturbed areas on 

 land and sea may reveal suggestive relationships with gravity anomalies and geological 

 formations. 



b. In view of the theoretical importance of magnetic and electric observations in 

 upper levels of the atmosphere (topics 3d and 5), it was considered highly desirable to 

 make arrangements for such observations as soon as facilities and conditions permit. 



