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XIII. Contributions to Terrestrial Magnetism. — No. XI. 
By Lieut. -General Edward Sabine, R.A., President of the Royal Society. 
Eeceived and Eead June 18, 1868. 
The object of the present (i. e. the Eleventh) Number of the Contributions to Terrestrial 
Magnetism is the completion of the great national undertaking, the Magnetic Survey of 
the South Polar Regions of the Globe, corresponding to the Epoch 1840-1845. 
The Survey originated in a Report presented to the British Association for the Advance- 
ment of Science at the Liverpool Meeting in 1837, entitled “ On the Variations of the 
Intensity of the Earth’s Magnetic Force observed at different points of the Earth’s 
Surface:” copies of this Report were widely circulated amongst the Members of the 
Association previously to the Meeting at Newcastle in the following year, 1838; and 
having received a favourable notice in the opening address of the then Secretaries of the 
Association, Dr. George Peacock and Sir Roderick Murchison, resolutions were passed 
by the General Committee, which are printed in pages xxi and xxii of the “ Annual 
Report of the Proceedings at Newcastle in August 1838.” These resolutions having 
been formally communicated to the Royal Society, a joint committee of the two scien- 
tific institutions was appointed to bring the subject of the equipment of a naval expedi- 
tion for magnetic observations in the Arctic Seas under the consideration of Her 
Majesty’s Government. A single sentence from the address of this Committee may 
be cited as evidencing the spirit in which the joint application of the Royal Society and 
of the British Association was made to Her Majesty’s Government. 
“The Committee consider the subject of Terrestrial Magnetism to have now attained 
a degree of theoretical as well as of practical importance, and to afford a scope for the 
application of exact inquiry, which it has never before enjoyed, and which are such as 
fully to justify its recommendation to the revival of that national support to which we 
are indebted for the first Chart of the Declinations, constructed by our illustrious coun- 
tryman Halley in 1701, on the basis of observations collected in a voyage expressly 
equipped for that purpose by the British Government”*. 
The Report of the Committee thus prepared and presented to Her Majesty’s Govern- 
ment (of which Lord Melbourne was at the time the Prime Minister) dwelt in some 
detail on the principal objects to be accomplished by the expedition recommended. The 
following passage may be especially cited as evidencing the early and just appreciation 
of the leading desiderata in magnetical science, and as furnishing to the readers of this 
paper the opportunity of judging of the degree in which the anticipations therein ex- 
pressed have been realized. 
* Proceedings of the Eoyal Society, December 22, 1838. 
3 F 
MDCCCLXVIII. 
