288 CARNEGIE INSTITUTION OF WASHINGTON. 



The iiuignetic data accumulated by the end of 1917 will warrant 

 undertaking then the reduction of all results to some conunon date by 

 applying the secular changes just mentioned. When this has been 

 done a new set of magnetic charts for the globe can be constructed on a 

 more accurate basis than has been possible heretofore. It is hoped 

 that the solution of some of the vexed and mooted questions pertaining 

 to the magnetism of our planet may then be undertaken successfully. 



Volume III, which shortly will be ready for distribution, contains 

 also a special report on the results of the atmospheric-electric observa- 

 tions made at sea on the Galilee and the Carnegie during the periods 

 1907-1908, and 1909-1916. By referring to the abstract on pages 326 

 to 329, it will he seen that results of importance have been obtained also 

 in this line of work. The improved methods and instruments in use 

 on the Carnegie since 1915 promise to yield further important facts. 



Magnetic data of interest to mariners have been mailed to the chief 

 hydrographic establishments with the same promptness as heretofore. 

 Owing to interrupted mail service in European countries, however, the 

 receipt of the data is at times delayed. With the publication of Volume 

 III, hydrographic establishments are put in possession of the complete 

 ocean magnetic results to September 1916. 



MAGNETIC SURVEY OF THE OCEANS. 



At the close of the last fiscal year the Carnegie was en route from 

 Dutch Harbor, Alaska, to Lyttelton, New Zealand, where she arrived, 

 after a continuous trip of 89 days, on November 3, 1915. After the 

 completion of the usual shore work and the instrumental comparisons 

 at Chiistchurch Magnetic Observatory, she sailed from Lyttelton 

 December 6 on a most memorable voyage — the circumnavigation of 

 the sub- Antarctic regions. Proceeding eastward for the greater part 

 near the parallel of about 60° south, she arrived at King Edward Cove, 

 South Georgia Island, in the South Atlantic, on January 12, 1916. 

 Leaving this port two days later, the Carnegie continued eastward and 

 returned to Lyttelton on April 1, 1916, having accomplished the 

 circumnavigation passage of 17,084 nautical iniles in 118 days, the 

 average day's run under sail being 145 miles. 



As far as is known, the Carnegie is the first vessel to make the circum- 

 navigation of the globe in the sub- Antarctic regions complete in one 

 season. On every day of the entire passage full sets of magnetic 

 observations were made, excepting on one day, when, because of cloudi- 

 ness, the value of the magnetic declination (variation of the compass) 

 could not be detennined ; however, on this day the magnetic inclina- 

 tion and the intensity of the Earth's magnetic field were observed. 

 Off the southwest coast of Australia, mariners' charts of the variation 

 of the compass were found in error 12° to 16°, the largest errors thus far 

 revealed. Besides important magnetic and electric data, information 



