20 



PROCEEDINGS OF SECTION A. 



2.— THE GENERAL MAGNETIC SURVEY OF AUSTRALIA 

 BY THE CARNEGIE INSTITUTION OF A\ ASHINGTON. 



By Edward Kidson, M.Sc. 



Plates 1 and 2. 



ABSTRACT. 



This work is part of a plan for a Magnetic Survey of the whole 

 world to be accomplished in a space of four years, in which the ocean 

 work and outstanding land work is entrusted to the Department of 

 Terrestrial Magnetism of the Carnegie Institution. The writer was 

 sent to Australia to undertake the observations in this country. The 

 object of the Department is to secure one observation station to about 

 every 10,000 square miles. The survey was begun in July, 1911, and, 

 in addition to miscellaneous work, about 140 stations have been occupied 

 so far. The ground covered includes the greater part of South 

 Australia, the railway lines of Western Australia, the overland route 

 from Oodnadatta to Port Darwin, and portions of North Queensland 

 and Victoria. Continuous observations extending over 24 hours were 

 taken of the declination at Port Darwin and of the horizontal intensity 

 at Laura, Queensland. These, together with the simultaneous 

 variations as given by the Melbourne Observatory magnetograms, are 

 plotted in Figs. 1 and 2. The observer has received great assistance and 

 encouragement from the Melbourne Observatory, the Surveyors-General 

 of the States visited, and various officials with whom he has come in 

 contact. A plea is made for detailed surveys in Australia by the 

 local authorities. Work has been done in recent years by almost every 

 other civilized country. 



Summary of Carnegie Institution Magnetic Observations in Australia. 



PRELIMINARY VALUES. 

 East declinations are positive and west negative. 



Date. 



1911. 

 July 31 

 Aug. 1 



3 

 i 



8 

 11 

 14 

 16 

 17 

 18 

 21 



E. 

 Long. 



142 

 142 

 140 

 139 

 139 

 138 

 138 

 138 

 138 

 135 

 136 

 135 



Remarks. 



