524 
GENERAL REMARKS. 
OTAHEITE. Observer. Date. Variation. 
Observer. Date. Variation. 3 On 
aay Flinders .. .. 1803 8. 51 E. 
Cook ee Lae 1760) 4 4 ane Freycinet... .. 1819 9g. 15 E. 
Wralestn-ce. 1773 5. 40 E. Duperrey.. .. 1824 8. 56 E. 
Bayleysese- <0) B774e 0G. wouky Fitz-Roy .. - 1836 10. 24 E. 
Vancouver .. 1794 6G. 12E, A 
Duperrey -. 1823 6. 40 EB. Van Diemen’s Lanp. 
Fitz-Roy.. .. 1835 7. 34E. Tasman .. .. 1642 3. 00 F. 
Bayley 24 96, 1777. 9 yaag) Be 
Bay or Isuanps, N. ZEALAND. Bligh .. .. 1778 8 33E. 
Tasman .. 1643 +8. 40 E, Fitz-Roy.. .. 1836 11, o6 E. 
Cook Lethe ma OOP N Lis 25 lee 
Duperrey 1824 13, 22 EF. : Mauvririvs. 
Fitz-Roy.. .. 1835 14. 00 E. Keeling .. . 1609 21. oW. 
Mathews.. .. 1722 19. 4W. 
SYDNEY. Freycinet -- 1818 12, 46W. 
Cook etl Seed LAZO mes, CONE, Duperrey «. 1824 13. 46W. 
Hunter .. 1787 8. 30 E. Fitz-Roy.. .. 1836 11, 18W. 
We may derive from the facts in the above table the following 
general and easily remembered conclusion in regard to the changes 
of the variation in the southern hemisphere ; namely, that taking for 
our point of departure the meridian of 65° west in South America, 
we find that at all the stations east of that meridian to the Cape of 
Good Hope inclusive, the north pole of the needle has moved 
towards the west ; and that all the stations west of the same meri- 
dian to Mauritius inclusive, the north pole of the needie has moved 
towards the east. 
An almost equally simple generalization may be drawn in respect 
to the changes of situation of the lines of equal variation in the 
southern hemisphere: but.here it must be supposed either that the 
reader is thoroughly familiar with the general arrangement of these 
lines, or that he has a map of them before him. He will find such 
a map of the variation lines in 1787 in the Fifth Report of the 
British Association ; but any other map, corresponding to any epoch 
within the last hundred years, will equally serve the purpose. 
Referring to such a map, it will be seen that the lines of variation 
in the South Pacific, form a system of nearly concentric curves, of 
an oval, or pear-shaped form, the outside curves having a higher 
variation, which progressively diminishes to the centre. We may 
regard this system as comprehending the whole of the geographical 
space between the coast of South America and the meridian of 
New Zealand. Throughout this space the variation is easterly, and 
increases: we may consequently characterize the change in the 
situation of the lines of equal variation as a progressive closipg-in 
