230 
MAJOR-GENERAL SABINE ON THE DISTURBANCES OE THE 
tion of the British Association for the Advancement of Science, assembled at Newcastle 
in September 1838, and concurred in by the President and Council of the Royal Society 
in the spring of 1839, the inquiry subsequently received under the sanction and with the 
warm support of the Ministry of which Lord Melbourne was the principal member, 
and the succeeding Administration of which Sir Robert Peel was the first minister. 
The field of research was no longer limited to a single continent, but included the most 
widely separated localities on the globe. Stations were selected in both hemispheres, and 
in the tropics, on continents and on islands, the selection being guided either by diversity 
of geographical circumstances, or by magnetical relations of prominent interest. The 
objects of investigation were also enlarged, so as to include not alone the transient and 
irregular fluctuations which had occupied the chief attention of the German Associations, 
but also “ the actual distribution of the magnetic influence over the globe at the present 
epoch in its mean or average state, together with all that is not permanent in the phe- 
nomena, whether it appear in the form of momentary, daily, monthly, semiannual or 
annual change and restoration, or in progressive changes, possibly not compensated by 
counter-changes, or possibly receiving compensation, either in whole or in part, in cycles 
of unknown relation and unknown period.” Suitable instruments, which in many 
respects were novel in construction, were provided for the observation of each of the 
three magnetic elements in this scheme of comprehensive research ; and a report, pre- 
pared with much deliberation and care by a special committee of the Royal Society, was 
printed for the instruction and guidance of those who should be employed in conducting 
the magnetic surveys by sea and land, and of those who should direct or superintend 
the investigations to be carried out at the stationary magnetic establishments. 
The present communication having reference to one branch only of one department 
of this extensive inquiry, viz. to that which relates to the magnetic disturbances , its 
notices are strictly limited to what may be necessary for placing before the Society as 
briefly as possible the successive steps which have advanced our knowledge of these 
phenomena, in respect to their diversities and mutual relations, their connexion with 
the general phenomena of terrestrial magnetism, and their probable cosmical origin. 
The simultaneity of the days on which magnetic disturbances take place had already 
been shown by the term-days of the Gottingen Association to be coextensive with its 
sphere of operation, viz. the greater part of the continent of Europe. The wider exten- 
sion of the British system, embracing stations in all quarters of the globe, now caused 
the fact of the simultaneity of disturbance to be recognized as a general feature common 
to the whole of our planet ; whilst the evidence of diversity in the action of individual 
forces, even in the most clear cases of synchronous disturbance, was even more distinctly 
manifested than in the previous more limited experience. Thus the comparison of the 
term-days in 1840, 1841, and 1842 observed at different stations on the continents of 
Europe and America, and collated in the first volume of the Observations at the Toronto 
Observatory, published in 1845, gave occasion to the following general conclusion: — 
“The correspondence so strikingly manifested in the fluctuations in America, and which 
