133 
Table I. 
MAGNETIC DIP. 
1873. 
1874. 
1 
1 1875. 
1 
1876. 
1 
; Mean of 
j 4 Years. 
69° 15-62 
13-65 
13-97 
15-72 
15-22 
15-70 
69° 14'-98 
January 
February... 
March 
April 
May 
June 
69° 19'-5 
14'-6 
17- 6 
18- 9 
17-7 
161 
69° 19'-5 
14- 7 
12-4 
16*8 
171 
15- 3 
69° 13'-8 
12- 3 
13- 2 
12- 4 
13- 6 
15-4 
69° 10'-7 
13-0 
*12-7 
*14-8 
*12-5 
160 
69° l7'-40 
15-80 
13 45 
13-28 j 
1873. 
1874. 
1875. 
1876, j 
Mean of 
4 Years. 
J uly 
August 
September ... 
October 
November ... 
December . . . 
69° 14/-6 
20‘2 
23-8 
16-8 
14-4 
18 3 
69° 14'-8 
14-4 
*12-8 
14-4 
n4‘5 
*13-6 
69° 10'-8 
13- 2 
14- 4 
15- 3 
141 
150 
69° 9'-9 
12- 7 
120 
13- 3 
8-2 
11-6 1 
69° 12^-52 
15-12 
15-75 
14-95 
12-80 
14-62 

69° 18'-02 
14-08 
13-80 j 11-28 
1 
69° 14'-30 
Yearly Means 
39° 17'-7l ( 
39° lF-94 ( 
39° 13'-62 
39° 12'-28 
69° lF-64 
The six numbers marked with an asterisk result from 
observations of one needle only, but as the mean annual 
difference of the readings for the two needles for these 
years differed by less than the tenth of a minute, no correc- 
tion has been applied to them. 
The annual and semi-annual inequalities of the dip cannot 
be accurately deduced from four years’ observations, but an 
approximation to the former is exhibited in the followino’ 
table. ® 
j Annual 
Decrease. 
Mean Dip in 1873 
„ in 1874 
1/ 71 
1 /I »n 4 
21 -11 
l'-32 ! 
« in 1875 .... 
oy 14 94 
„ in 1876 .... 

OU lo oii 
69 12 -28 
l'*34 
1 Mean . . . . , 
69° 14'-64 
l'-81 
