AND LEICESTERSHIRE AND TPIEIR RELATIONS TO GEOLOGICAL STRUCTURE. 81 
Subtracting the mean in each case we get the 
Relative Disturbing Forces. 
— 
North. 
West. 
1 
Vertical. 
i 
Asfordby. 
-79 
- 57 
1 
- 23 
Waltham . ,. 
-71 
+ 16 
- 134 
Seagrave . 
+ .32 
- 36 
- 73 
Melton. 
+ 22 
+ 258 
+ 89 
Broughton . 
-30 
+ 8 
- 7 
Penhill. 
+ 49 
+ 61 
+ 58 
Keyworth. 
+ 30 
+ 8 
+ 14 
Berryhill. 
+ 8 
- 13 
+ 27 
Plumtree. 
+ 10 
- 35 
- 10 
Barton. 
+ 40 
- 51 
+ 29 
Rempstone. 
- 78 
- 38 
+ 170 
Loughborough . 
+ 65 
f 
- 116 
- 87 
Observations made at neighbouring stations during the General Magnetic Survey 
in 1914-15, and corrected to epoch January 1, 1915 :— 
Nottingham. 
+ 38 
- 17 
+ 230 
Or relative. 
+ 80 
- 23 
+ 170 
Coalville. 
+ 42 
- 101 
+ 30 
Or relative. 
+ 84 
- 107 
- 30 about 3| miles W.S.W. 
of Loughborough. 
Thus the interferences drawn from the General Magnetic Survey are substantially 
confirmed. I am not surprised by the discrepancy in D at Loughborough because 
the General Survey observations there were made, as it turned out, during a 
magnetic storm of considerable violence. But the comparatively large drop of 33 
in H at Melton (which accounts for the drop of lOOy in V) appears to me too 
large to be accounted for by observational error, although it is true that the recent 
observation at Melton was made during a very high wind with intermittent thunder 
and heavy rain. 
Notwithstanding this drop Melton still remains a point of large westerly disturbance 
and large downward disturbance. 
That the large disturbances at Melton and Loughborough are not directly due to 
one and the same centre of disturbance is shown by the distribution of the forces at 
the intermediate points Asfordby and Seagrave. 
The system of disturbing forces is evidently a somewhat complicated one and 
admits of several interpretations, so that additional observations appear necessary to 
make the problem more definite. Meanwhile attention may be directed to the 
VOL. CCXIX.—A. 
M 
