ANTARCTIC AND SOUTHERN EXPLORATION. jan 
For all useful purposes it is not necessary that the explorers 
should waste much time in trying to reach the earth’s axis, a mere 
mathematical point ; it would be sufficient for all scientific pur- 
poses that an approach to it should be made within three or four 
degrees of latitude. 
It is curious to reflect what would be the experience of those, 
if any, who should happen to reach this mathematical point, the 
actual position of which could only be determined by an altitude 
of the sun, giving as its zenith distance the complement of 90° of 
its declination for its latitude. The sun itself from such a point 
could have no change in altitude except such as was daily caused 
by increase or decrease of its declination or motion on the ecliptic, 
coupled with its motion in right ascension. As for “time,” the 
explorers would have to make their own, being unable to obtain 
an hour angle from any of the heavenly bodies ; they could get no 
apparent time, but they might get an approximate time by observ- 
ing a Junar distance and getting Greenwich time from a nautical 
almanac. Having thus obtained Greenwich time, it would thence- 
forth be their time, and the meridian of Greenwich could be deter- 
mined as their starting-point. Longitude, they could have none, 
being at the convergence of all the meridians. Standing at the 
South Pole their only line of vision would be northerly along a 
north meridian line. 
I may, perhaps, remind you that the so-called N. end of the 
needle is also termed the ‘‘marked” end of the needle or North- 
seeking Pole, and in France the north-seeking end is termed the 
Austral or Southern Pole, and the south-seeking end the Boreal 
or Northern Pole. 
It is interesting to read Sir J. C. Ross’s accounts of his mag- 
netical observations. The fixing of the site of the south magnetic 
pole would naturally be the leader’s ambition. 
Various positions have been assigned to it. Duperry, the 
French navigator, in 1825, had, several times, crossed and recrossed 
the magnetic equator, and from observations of variation and dip, 
had calculated its position. Professor Gauss, in his study at 
Gottingen, had also assigned a position, but no one quite agreed 
with Sir James Ross's observations. His approach to it is graphi- 
eally described in the account of his voyages. 
“We were in latitude 76° 12'S. longitude 164° E. ; the magnetic 
dip 88° 40’, and the variation 109° 24’ E. We were, therefore, 
only 160 miles from the Pole. It was painfully vexatious to 
behold at an easily accessible distance, under other circumstances, 
the range of mountains in which the Pole is placed. I felt myself, 
however, compelled to abandon the perhaps too ambitious hope, 
that I might plant the flag of my country on both the magnetic 
poles of our globe.” 
