OBJECT OF EOSS'S VOYAGE 49 
tion, undergoing local and transitory as well as periodical 
changes. Observations, moreover, must extend over a long 
period. 
The many explorers within the Arctic Circle had recorded 
much information. Eoss himself had found the Northern 
Magnetic Pole and seen the compass dip vertically to 90°, and 
Gauss had calculated the Southern Magnetic Pole to lie in 
72° 35' S., 152° 30' E. But as his materials were imperfect 
and the position he had calculated for the Northern Pole was 
3° wrong, he inferred the Southern Pole to be in 66° S. and 
160° E. His inference required verification. Permanent sta- 
tions should be established at suitable spots in the Southern 
hemisphere, where simultaneous observations might be main- 
tained in connection with the European stations, while the 
Erehus and Terror acted as floating observatories on their 
voyage. Besides the hourly records of the three variables 
every day for three years, on the four * term days ' of the 
European Magnetic Association simultaneous records were 
to be kept at intervals of not more than five minutes during 
the twenty-four hours : in fact, on the term day which fell 
in Tasmania, Eoss and his colleagues took these observations 
at intervals of two and a half minutes. 
These considerations took shape in a series of resolutions 
passed by the British Association for the Advancement of 
Science in 1888. They were pressed upon Lord Melbourne's 
Government by an influential Committee and strongly supported 
by the President and Council of the Eoyal Society, to whom 
they were referred as the acknowledged advisers of Government 
in matters of science. But it was not till the foreign scientific 
institutions, led by Humboldt himself at Sabine's suggestion, 
threw their weight into the scale, pleading for national co- 
operation in magnetic work where private enterprise was out 
of the question, and urging the superiority of the British Navy 
and the unequalled experience of its officers in polar work, that 
the Government early in 1S39 agreed to fit out the expedition 
at a cost of £100,000. 
As a result two exploring ships, each with a crew of sixty- 
four men, were carefully fitted out under the experienced Arctic 
