527 
GENERAL REMARKS. 
alternate increase and decrease of dip. Commencing with the 
meridian of Greenwich, and proceeding eastwardly round the 
hemisphere, we may distinguish the divisions as follows, in the 
order of their geographical succession. 
Ist. South dip increasing. 
annually. annually, 
St. Helena... .. 1754 to 1775-..6,9/| Cape of GoodHope 1775 to 1836. . 6,6. 
Do. «- .»- 1775 to 1836..6,5 | Mauritius .. .. 1754 to 1824..1,3 
Cape of Good Hope 175! to 1775.-7,2 Do. ee oe 1824 to 1836..0,8 
To this division also belongs Ascension ; but as the north end of 
the needie dips at that island, the change is north dip diminishing, 
instead of south dip increasing. 
Ascension .. .. «- 1754t01775 .-. 6,3 annually. 
Do. Pepesta eset LAV tOLGsO 5/752 
2d. South dip decreasing. 
New Zealand «. «. 1824t01835 .. 1,2 annually.* 
3d. South dip increasing. 
Otaheite we «ce ce 1775101896 .. 0,5 annually. 
Ath. South dip decreasing. 
ns annually. annually. 
LimaandCallao.. 1710 to 1799..0,4/| Tierra del Fuego 1774 to 1828..8,0 
Do. .. .. 1799 to 1835.-4,9 | Falkland Islands 1820 to 1834... 8,2 
Valparaiso +» «. 1794 to 1835 10,0 | St? Catharina .. 1822 to 1827..8,4 
Concepcion.. .. 1710 to 1786..3,7 | Rio de Janeiro .. 1751 to 1817.. 4,8 
Dory 3.) 1786)to 1895-2853 Do. .- «. 1817 to 1832..4,3 
In the 2d and 3d divisions the annual change is small; in the 
Ist and 4th considerably greater. It is greatest at the southern 
station in South America; the observations at Valparaiso, ‘{Con- 
cep¢ion, Tierra del Fuego» and the Falkland Islands, concur in 
shewing it to exceed 8’. The observations at Ascension, St. Helena, 
and the Cape of Good Hope, concur in shewing an annual change 
in that quarter of the Ist division exceeding 6’. 
As the south dip decreases in South America, and increases in 
Africa, it is obvious that somewhere intermediately the dip must 
be stationary. Between Africa and New Zealand, for the same 
reason, there must be a second locality so characterised. Between 
New Zealand and Otaheite, a third ; and between Otaheite and the 
west coast of South America, a fourth. Captain Fitz-Roy has 
* This is derived from the observations of Captains Duperrey and Fitz-Roy 
at the Bay of Islands, in Lat. 35°. 16’. The intervalis short ; but the indication 
receives confirmation from the observations of Captains Cook and Vancouver at 
Dusky Bay, New Zealand, in Lat. 45°. 47/. 
Goakaasadeg sau rere 1700s 06! 
uf 1 rease. 
Vancouver.. 1791 .. 69. 43 ; 4 annual avcrers 
