LIEIJT.-GENERAL SABINE ON TERRESTRIAL MAGNETISM. 
373 
latitudes of 60° and 70° only by a continual inclination towards the west, which at length 
conducted them in 7 0° of latitude to the vicinity of their previous explorations and of the 
great glacier which had barred their southerly progress in the preceding year. After 
revisiting some of the geographical positions in which the magnetic observations of the 
preceding year had been made, and thus verifying their earlier results, the ships returned 
to the more navigable parallels of 59° and 60°, and, traversing the South Pacific in about 
the latitude of 60°, rounded Cape Horn and arrived at Port Louis in the Falkland 
Islands in August 1842. Here the ships were refitted, and, sailing thence in Sep- 
tember 1842, passed some days at St. Martin’s Cove near Cape Horn, where very careful 
examinations and comparisons of the magnetic instruments were made. Returning to 
Port Louis, and sailing thence on the 17th of December 1842, the ships resumed 
their eastern progress, continuing the habit of daily observation of the three magnetic 
elements, and availing themselves of every occasion which presented itself of attaining a 
higher south latitude. One notable opportunity occurred towards the end of February 
and beginning of March, when the 71st parallel was reached, but with great difficulty 
and considerable peril. 
On the 4th of April 1843 the ships arrived at Simon’s Bay in the vicinity of the Cape 
of Good Hope, thus completing the third year of the Survey, as well as the circumnavi- 
gation of the globe. 
It was the practice of Sir James Ross and Captain Crozier on all convenient occa- 
sions during the Survey to transmit the successive records of their observations to the 
Admiralty, by whom on their arrival they were sent to me for examination and reduc- 
tion, pursuant to an arrangement between the Departments of the Admiralty and of the 
Ordnance, in which provision had been made for those purposes in an office under my 
superintendence at Woolwich. These original records have been carefully preserved, 
and will be deposited for all future reference (if required) in the Archives of the Royal 
Society. No time was lost, on the reception of these documents, in making such a pro- 
visional calculation of the results as circumstances would then permit, and in commu- 
nicating both the observations themselves and the results to the Royal Society. The 
instruments employed being for the most part of novel design, and the conduct and 
execution of a magnetic survey at sea being scarcely less so (especially of a survey which 
should include the three magnetic elements), the provisional character of these commu- 
nications was from the first distinctly recognized, and a final publication, such as the 
present purports to be, was throughout contemplated. With this understanding the 
observations of the first year of the Antarctic Survey, with their results provisionally 
computed, were communicated to the Royal Society in 1843, and printed in the Philo- 
sophical Transactions for that year, forming the Y.th Number of these Contributions ; 
those of the second year in 1844, forming the Yl.th Number; and those of the third 
year in 1866, forming the X.th Number of the Contributions to Terrestrial Magnetism. 
The success with which such Surveys could be prosecuted at sea having been shown 
by the first two of the publications thus referred to, the Royal Society was emboldened to 
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