SURVEY OF THE BRITISH ISLES FOR THE EPOCH JANUARY I, 1886. 289 
station on the other side of the town, about a mile and a half distant from the first, 
was chosen, and the new observation was made under favourable conditions at about 
5.45 p.M. The result indicated a Declination disturbance of + 26', which Avas in 
close accord with that previously obtained. At first sight, then, it appears that the 
peculiarities of the district might be explained by the hypothesis that a centre of 
force, powerful relatively to Charnwood Forest, exists somewhere betAA^een Melton 
Mowbray and Loughborough. Tlie disturbances of the Declination at these two 
stations are in opposite directions and of nearly equal amounts. This view does not, 
however, correspond with the directions of the disturbing forces obtained at Melton 
Mowbray. If it Avere correct they should both have acted in nearly parallel 
directions towards the west, x4s a matter of fact, at the first station the disturbing 
force acts nearly due Avest, Avhile at the second it is only 11° from south. 
This indicates that the disturbance at Melton Mowbray is of a more local character, 
and cannot, in the manner suggested, be brought into relation Avuth the oppositely 
directed disturbances at Coalville and Loughborough. 
If, however, we timi from the Horizontal to the Vertical disturbing Forces we find 
that the peculiarities of these various stations may be connected, and that a magnetic 
map of the district can be draAvn Avhich may furnish the first rough outlines to which 
details may hereafter be added Avithout rendering them substantially incorrect. 
This explanation is based upon the fact that Avhereas in this part of England 
the disturbances of the Vertical Forces are for the most part positive, at four con¬ 
secutive stations in this neighbourhood they are negative. 
These stations are Coalville, Leicester, Kettering, and Northampton. Whether 
the loAv Vertical Forces are due to the presence of a repulsive centre, or to a deep cleft 
or valley in the attracting mass, Ave cannot tell. Indeed, the latter hypothesis might 
account for a repulsion if the mass of attracting matter Avhich Ave have supposed to 
culminate in the Reading peak terminated abruptly on its northern edge. For, if it 
were magnetised by induction it is possible that some of the lines of force might 
escape upwards to the surface, diminish the Vertical Force, and urge the north pole 
northwards. 
Contour lines draAA’n as in tlie accompanying map (fig. 21), indicate the possibility 
of a very sudden rise in the magnetic matter from a line drawn through Coalville, 
Leicester, and Kettering, to another Avhich passes through Chesterfield, Nottingham, 
Melton Mowbray, and Peterborough. This vieAv is supported by the fact that a 
ridge line, on passage across which the disturbance of the Declination changes sign, 
runs from near Chesterfield to near Melton MoAApray. 
If this view were correct, Melton MoAvbray would have to be regarded as near the 
summit of an extremely steep peak, as the Vertical Force changed from 0'0305 to 
0'0080 in the small distance betAveen the tAAm stations. The direction of the 
Horizontal Forces Avould indicate a point a little to the Avest of both sta.tions as the 
actual peak. 
MDCCCXC.—A. 2 i> 
