322 
LITTLEHALES. 
Lat. 24° 38' N. MAGDALENA BAY. Long. 112° 07' W. 
Year. 
Magnetic 
dip or in¬ 
clination. 
Authority. 
Observer. 
Where recorded. 
1837. 
o 
+50.72 
+48.53 
Do Petit Thenars.. 
Phil. Trans. Royal Society, 1875. 
Smithsonian Contributions to Knowledge, No. 
239, 1873. 
1866.5 .... 
Harkness 
1873.2 .... 
+48.15 
W.Eimbeck,assistant,Coast 
and Geodetic Survey. 
Coast and Geodesic Survey Report for 1881. 
1881.2 .... 
+48.32 
Lieut. Commander H. E. 
Nichols, U. S. N. 
I)o. 
1895.2 .... 
+48.52 
Lieut. F. 
U. S. N. 
M. Bostwick, 
Hydrographic Office archives document. 
Year. 
Observed. 
Computed. 
O-C. 
- 2 
O-C . 
1837. 
o 
+50.72 
o 
+50.71 
+0.01 
0.0001 
1 
! 
1866.5 .... 
+48.53 
+48.46 
+0.07 
0.0049 
1873.2 .... 
+48.15 
+48.28 
—0.13 
0.0169 
• Probable error of a single observation = ± 5'. 
1881.2 .... 
+48.32 
+48.23 
+0.09 
0.0081 
1895.2 .... 
+48.52 
+48.54 
—0.02 
0.0004 
0.0304 
Empirical equation for determining the inclination for any year: I = 48 °.26 — 
0.0135 (t — 1875) + 0.00135 (t — 1875) 2 , 
