306 
LITTLEHALES. 
Lat. 7° 55.5' S. ASCENSION ISLAND. Long. 14° 24' W. 
Year. 
Magnetic 
dip or in¬ 
clination. 
Authority. 
Observer. 
Where recorded. 
1754 
o 
4-11.16 
Hansteen’s Magnetismus der Erde, Christiania, 
1819. 
1775 . 
+ 8.95 
.T- Conk. 
Do. 
1895! ... 
+ 5.16 
Becquerel’s Traite du Magnetisme, 1846. 
1834 
+ 1.95 
Phil. Trans. Royal Society, Part II. 1877. 
1836. 
+ 1.65 
Fitz Roy.. 
Do. 
1839. 
+ 0.10 
Du Petit Thouars. 
Do. 
1842. 
— 0.13 
Allen .. 
Do. 
1852.9 .... 
- 4.12 
“ L’Eugenie ”. 
Annalen der Hydrographie, 1877. 
(1863 — 4.78 
H. M. S. Hecate. 
Phil. Trans. Royal Society, Part II, 1877. 
-LOUO.O •... 
1 1864 — 5.95 
Rokeby . 
Do. 
1876.2 .... 
— 7.75 
H. M. S. Challenger. 
Voyage of H. M. S. Challenger. 
1890.2 .... 
-11.63 
E. D. Preston, assistant, 
Coast and Geodetic Survey Report, 1891. 
Coast and Geodetic 
Survey. 
Year. 
Observed. 
Computed. 
O-C. 
o-c 2 . 
1754. 
o 
+11.16 
O 
+11.10 
+0.06 
0.0036 
' 
1775. 
+ 8.95 
+10.94 
—1.99 
3.9601 
* 
1822. 
+ 5.16 
+ 3.62 
+1.54 
2.3716 
1834. 
+ 1.95 
+ 1.33 
+0.62 
0.3844 
1836. 
+ 1.65 
+ 0.91 
+0.74 
0.5476 
Probable error of a single observation = ± 44'. 
1839. 
+ 0.10 
+ 0.29 
—0.19 
0.0361 
- 
Period — 600 years. 
1842. 
— 0.13 
— 0.34 
+0-21& 
0.0441 
1852.9 .... 
— 4.12 
— 2.76 
—1.36 
1.8496 
1863.5 .... 
— 5.37 
— 5.18 
—0.19 
0.0361 
187,6.2 .... 
— 7.75 
— 8.22 
+0.47 
0.2209 
1890.2 .... 
—11.63 
—11.63 
0.00 
0.0000 
9.4541 
Empirical equation for determining the inclination for any year: 1 = — 12°.32 
— 21.24 sin 0.6 (< — 1850) + 10.24 cos 0.6 (t — 1850). 
