REPORT OF THE COUNCIL. XXXVII 



Welsh's Magnetic Survey of Scotland, as having led to important conclusions 

 as to the nature of the changes which have taken place in the luaguetic 

 system of the British Isles since 1837, — changes corroborated by a series of 

 determinations at several stations along the South-western and Southern 

 coasts of England, obtained by General Sabine himself in the course of the 

 current year, since the re-establishment of his health has permitted his invalu- 

 able services to become once more available to science. 



In concluding this Report, your Committee cannot but observe that all the 

 reasons which weighed with them in recommending, jointly with the Com- 

 mittee appointed by the Royal Society, the Resolutions adopted by the General 

 Committee of the British Association at their meeting of last year, for the 

 establishment of Observatories for an additional period of five years at the 

 stations named in their last Report, appear to them to remain in full force; 

 and that even supposing the idea of a station on the Falkland Isles, and even 

 Newfoundland, to be relinquished, they would continue to urge, as fitting 

 objects for recommendation to Government, those of Vancouver's Island and 

 Shanghai. 



While nothing has occurred to weaken the general reasons adduced in that 

 Report, they appear to have, in one respect, gained some degree of additional 

 weight from the reappearance, during the present year, of the Solar Spots in 

 great abundance, accompanied with exhibitions of auroral phenomena, and 

 of an unusually hot and dry season — all in conformity with the law of period- 

 icity alluded to in it as connecting, in some at present hidden and problematic 

 manner, these phenomena with the magnetic disturbances. 



(For the joint Committees) J. F. W. Herschel. 



Postscript. — The following Memorandum, drawn up and communicated 

 by General Sabine, containing a synoptic statement of the proceedings taken 

 in respect of Magnetic Surveys at the instance or through the intervention 

 of the British Association, may, in the opinion of the Committee, be very 

 properly appended to this Report. 



A Memorandum regarding Magnetic Surveys wJiich have originated, or been 

 promoted by the British Association for the Advancement of Science. 



August 19, 1859. 



1. The first occurrence, it is believed, of a survey being undertaken for 

 the express purpose of determining the positions and values of the isomag- 

 netic lines of declination, dip, and force corresponding to a particular epoch 

 over the whole face of a country or state, was the Magnetic Survey of the 

 British Islands, executed in 1834-1838 by a committee of members of the 

 British Association, acting upon an enlarged view of a suggestion brought 

 before the Cambridge Meeting of the Association in 1833. The results of 

 this Survey, in the determination of the isoclinal and isodynamic lines in 

 Great Britain and Ireland corresponding to the epoch of January 1st, 1837, 

 were published in a memoir in the Transactions of the British Association 

 for 1838 ; and in the determination of the isogonic lines, in the Philsophical 

 Transactions for 1849, Part II. 



2. At the Newcastle Meeting of the Association in 1838, a resolution was 

 passed recommending to Her Majesty's Government the equipment of a Naval 

 Expedition for the purpose of making a Magnetic Survey in the Southern 

 portions of the Atlantic and Pacific Oceans, and particularly in the higher 

 latitudes between the meridians of New Holland and Cape Horn. This re- 

 commendation, communicated to and concurred in by the Royal Society. 



