C 333 ] 
has increafed from 2°i W. to 12 0 JW.; and in lati- 
tude if 0 N. longitude 20° W. it has increafed from 
1 0 W. to c) a W. 
But there is ftill a more extraordinary appearance 
in the Indian feas : for inftance, under the equator. 
Longi- 
Variation in 
Longi- 
Variation in 
tude 
tude 
from 
1700. 
1 756- 
from 
1700. 
1756. 
London 
London 
Degrees. 
Degrees. 
Degrees. 
Degrees. 
Degrees. 
Degrees. 
40 E 
16J w 
16I W 
* 
75 E 
94 W 
I w 
45 E 
i?i W 
I4tW 
80 E 
74 w 
04 E 
^0 E 
I 7 f w 
ii| W 
85 E 
5 iW 
i| E 
55 E 
1 6 2 W 
81 - W 
90 E 
4 * W 
1 E 
60 E 
i 5 * W 
6 W 
95 E 
37 W 
o| W 
65 E 
i 3 hW 
4? W 
100 E 
2f W 
1 W 
70 E 
Iii w 
37 W 
Where the weft variation in the longitude 40° E. is 
the fame in both the above years ; and in 1 700 the 
weft variation feemed to be regularly deerealing from 
longitude jo 0 E. to the longitude ioo°E.; but in 
175-6 we find the weft variation decreafing fo faft, 
that we have eaft variation in the longitude 8c°, 85% 
and 9o°E ; and yet, in the longitude 95 0 and ioo° E. 
we have weft variation again. 
Such are the irregularities, that experience hath 
fhewn us, in the variation of the magnetic needle j 
which appear fo confiderable, that we cannot think 
it wholly under the direction of one general and uni- 
form law; but rather conclude, with the learned and 
judicious Dr. Gowen Knight, Fellow of this Society, 
in the 87th prop, of his treatife upon attraction and 
repuifion, That it is influenced by various and different 
magnetic 
