SURVEY OF BELGIUM IN 1871. 
357 
perceive two apparent centres of disturbing action, — the one situated in the N.W. 
centre, and manifested by a great increase of the Dip and a diminution of the Horizontal 
Force, and the other, more extended and less intense, stretching along the Coal-measures, 
and giving evidence of its existence by a diminution of the Dip and an increase of the 
Horizontal component of the Intensity. 
The dotted lines are an enlarged reproduction of the curves on Lamont’s maps ; and 
from being enlarged they will naturally give a somewhat exaggerated idea of the lesser 
inequalities, though the general curvature be perfectly correct. 
I will now conclude this paper with a list of the magnetic elements at the several 
stations, the observations being all reduced to the common epoch, January 1st, 1872. 
In this reduction I have adopted the yearly changes determined by the survey, viz. 
— (>0573, 0*00542, — (b01155, and — 0T255 respectively for the Dip, H. F., T. F., 
and the corrected Declination. 
Table XIX. 
Station. 
Declination. 
Dip. 
Horizontal Force. 
Total Force. 
Aix-la-Chapelle 
16-464 
66-637 
4 0064 
• 
10-1025 
Alost 
17-349 
67 210 
3-9518 
10-2016 
Antwerp 
17-489 
66-999 
3-9296 
10-0559 
Arlon 
16-398 
65-907 
4-1175 
10-0857 
Bruges 
17938 
67155 
3-8950 
100321 
Brussels 
17-959 
66-975 
3-9613 
101271 
Courtray 
17 756 
66-678 
4-0028 
10-1103 
Ghent 
17-823 
67-221 
39197 
101232 
Liege 
16-233 
66-464 
40145 
100522 
66-948 
Louvain 
16-894 
66-898 
3-9565 
100828 
66-714 
Mons 
17-216 
66-573 
4-0065 
10-0767 
Namur 
17541 
66538 
3-9941 
100311 
Ostencl 
18-097 
67-211 
3-9152 
10-1077 
Spa 
16 627 
66-653 
40239 
10-1531 
Tournay 
17-691 
66-632 
3-9975 
10-0776 
Troncliiennes 
17-867 
67361 
3-9032 
10-1397 
Turnhout 
17025 
67 1 13 
3-9542 
101665 
66-718 
O B 
MDCCCLXXIII. 
