Edmund Halley. 
97 
1880.] 
centre of the earth, but which rotated round its axis a little 
slower than the superficial portions of the earth. The nu- 
cleus and the exterior shell he regarded as two distindt 
magnets, having magnetic poles not coincident with the 
geographical poles of the earth. The change observed in 
Hudson’s Bay being much less than that observed in Europe, 
Halley concluded that the North American pole was fixed, 
while the European one was movable ; and, from a similar 
observation on the coast of Java, he considered the Asian 
South Pole as fixed, and the pole west of the Straits of 
Magellan to be in motion. The fixed poles he regarded as 
those of the external shell, and the movable as those of the 
inner nucleus. Of these latter the one placed by him in 
the meridian of the Land’s End was ascertained, in the 
present century, to have moved to Siberia in 120 0 E. long., 
and that placed by him 20° from the Straits of Magellan to 
have moved between 30° and 40° west of this position ; while 
those poles regarded by Halley as fixed were found but 
slightly altered in position since his time. It is extremely 
interesting to find that not only modern observations of 
declination, but also those of dip and magnetic intensity, 
have received their best explanation on the assumption ot 
four magnetic poles. Much, however, that is mysterious 
remains unsolved, and Halley’s remarkable words may even 
now with truth be quoted “ Whether these magnetical 
poles move altogether with one motion or with several, 
whether equally or unequally, whether circular or libratory, 
if circular about what centre, if libratory after what manner, 
are secrets as yet utterly unknown to mankind, and are 
reserved for the industry of future ages.” — (“ K.” ibid.) 
Intent on still further carrying out his magnetic researches, 
Halley was successful in an application to King William to 
fit out a scientific expedition, and in 1698, as Capt. Halley, 
R.N., received his appointment to the command of H.M.S. 
Paramour , in which vessel, a Pink (?), his sailing orders 
directed him to seek by observations the discovery ot the 
rule of variations of the compass, and as well to survey and 
lay down the latitude and longitude of His Majesty’s Ame- 
rican settlements. The Paramour left England in November, 
1698, but was absent only for seven months, on account of 
sickness breaking out among the. crew during their stay in 
the equatorial calms, and his Lieutenant mutinying. On 
their return home the Lieutenant was court-martialled and 
cashiered ; and Capt. Halley, in no way disheartened, and 
with his expedition augmented by the presence of a smaller 
consort placed under him, set off in September, 1699, and 
