288 
LITTLEHALES. 
Lat. 22° 16 / N. 
HONGKONG, CHINA. 
Long. 114° 10' E. 
Year. 
Magnetic 
declina- 
• tion. 
Authority. 
Observer. 
Where recorded. 
1780.. .. 
1792.. .. 
1824.. .. 
1827.. .. 
1830.. .. 
1837.. .. 
1843.. .. 
1855.. .. 
1875.. .. 
1876.. .. 
1884.. .. 
1885.5 
1887.5 
+0.50 
—1.28 
—1.70 
— 2.00 
—1.58 
—1.08 
—0.62 
—0.50 
—0.93 
—0.60 
—0.77 
—0.75 
—0.70 
Cook. 
Bougainville 
Beechey. 
Laplace. 
Darandeau.... 
Belcher. 
| Richards, 
Doberck 
Hansteen’s Magnetismus der Erde, Christiana, 
1819. 
. Brewster’s Treatise on Magnetism, Edinburg, 
1837. 
Becquerel’s Traite du Magnetisme. 
Phil. Trans. Royal Society, Part I, 1875. 
Do. 
Do. 
Do. 
f Observations and Researches at Hongkong, by 
\ W. Doberck. 
Annales Hydrographiques, 1876. 
f Observations and Researches made at Hong- 
\ kong, by W. Doberck. 
Hongkong, Government Gazette, May 31, 1888. 
Year. 
Observed. 
Computed. 
O-C. 
- 2 
O-C . 
o 
o 
Wts. 
1780. 
+0.50 
-0.48 
+0.98 
0.9604 
x 
0.2401 
1792. 
—1.28 
—0.70 
—0.58 
0.3364 
* 
0.0841 
1824. 
—1.70 
—1.06 
—0.64 
0.4096 
x 
0.2048 
1827. 
— 2.00 
—1.08 
—0.92 
0.8464 
X 
0.2116 
1830. 
—1.58 
—1.08 
—0.50 
0.2500 
1 
B 
0.1250 
1837. 
—1.08 
—1.09 
+ 0.01 
0.0001 
X 
0.0001 
1843. 
—0.62 
—1.08 
+0.46 
0.2116 
1 
0.2116 
1855. 
—0.50 
—1.03 
+0.53 
0.2809 
1 
0.2809 
1875. 
—0.93 
—0.80 
—0.13 
0.0169 
1 
0.0169 
1876. 
—0.60 
—0.79 
+0.19 
0.0361 
1 
0.0361 
1884. 
—0.77 
—0.65 
— 0.12 
0.0144 
1 
0.0144 
1885.5 .... 
—0.75 
—0.62 
—0.13 
0.0169 
1 
0.0169 
1887.5 .... 
—0.70 
—0.59 
— 0.11 
0.0121 
1 
0.0121 
1.4546 
Probable error of a single observa 
tion = + 15'. 
Period — 450 years. 
Empirical equation for determining the declination for any year: i> = 0°.990 4- 
0.389 sin 0.8 {t — 1850) — 2.047 cos 0.8 (t — 1850). 
