336 
LITTLEHALES. 
Lat. 33° 02 / S. VALPARAISO. Long. 71° 39' W. 
Year. 
Magnetic 
dip or in¬ 
clination. 
Authority. 
Observer. 
Where recorded. 
1700 . 
O 
—44.96 
Bode’s Astronomisches Jahrbucli, 1828. 
1827 
—39.10 
Phil. Trans. Royal Society, Part II, 1877. 
1830........ 
—40.19 
King. 
Do. 
1885 . 
—38.05 
Do. 
1836. 
—37.08 
Do. 
1887 
—38 33 
Do. 
1838 
—38.72 
Do. 
1838 
—38.20 
.do. 
Do. 
1852. 
—36.80 
Swedish Magnetic Survey... 
Annalen der Hydrographie, 1877. 
1859. 
—35.67 
Novara 'Exoedition. 
Phil. Trans. Royal Society, Part II, 1877. 
1866. 
—35.38 
"HTarkness 
Do. 
1868 ... 
—34.38 
H. M. S. Nassau. 
Do. 
1875.9 .... 
—33.79 
H. M. S. Challenger. 
Voyage of H. M. S. Challenger. 
1875.9 .... 
—32.57 
Do. 
1893. 
—31.83 
Lieutenant Mottez. 
, Fr. N.... 
Annales Hydrographiques, 2d vol., 1893. 
Year. 
Observed. 
Computed. 
O-C. 
0=C. 
1790.... 
o 
—44.96 
o 
—44.76 
—0.20 
0.0400 
1827. 
—39.10 
—39.73 
+0.63 
0.3969 
1830. 
—40.19 
—39.31 
—0.88 
0.7744 
1835. 
—38.05 
—38.60 
+0.55 
0.3025 
1836. 
—37.08 
—38.45 
+1.37 
1.8769 
1837. 
—38.33 
—38.32 
—0.01 
0.0001 
1838. 
—38.72 
—38.17 
—0.55 
0.3025 
Probable error of a single observation — ±28'. 
1838. 
—38.20 
—38.17 
—0.03 
0.0009 
1 Period = 400 years. 
1852. 
—36.80 
—36.32 
—0.48 
0.2304 
1859...:.... 
—35.67 
—35.40 
—0.27 
0.0729 
1866. 
—35.38 
—34.56 
—0.82 
0.6724 
1868. 
—34.38 
-34.33 
—0.05 
0.0025 
1875.9 .... 
—33.79 
—33.49 
—0.30 
0.0900 
1875.9 .... 
—32.57 
—33.49 
+0.92 
0.8464 
1893. 
—31.83 
—32.04 
+0.21 
0.0441 
5.6529 
Empirical equation for determining the inclination for any year: I = — 39°.99 
+ 8.41 sin 0.9 (t — 1850) + 3.45 cos 0.9 (t — 1850). 
