288 
MR. A. W. RTJCKER AND DR. T. E. THORPE OR A MAGNETIC 
These results make it certain that near the south of the Wash the Declination 
diminishes instead of increasing (as at normal stations) with the longitude. 
The accompanying map shows the directions and magnitudes of the disturbing forces 
in this district. They indicate a centre of attraction to the north of the line wdiich 
joins Spalding and King’s Lynn. 
The Leicestershire District. 
Another series of local disturbances exists to the west of that which has just been 
described. The facts which first attracted our attention to it were that at two pairs of 
stations, viz., Birmingham and Northampton, Leicester and Peterborough, the observed 
Declination at the more westerly was only about 2' greater than that at the more 
easterly station, though the calculated differences were as much as 35' in the first case, 
and 27' in the second case. 
The observations indicated that in this district the isogonal lines run nearly east 
and west instead of nearly north and south, and we proceeded to investigate their 
forms more closely. We thought that the anomaly wms probably connected with 
the fact that in Charnwood Forest, which is not very distant from Leicester, igneous 
rocks appear upon the surface, and observations were made round this district, though 
we were always careful that our station should be on what was apparently good 
observing ground. 
We have thus confirmed the existence of a great easterly trend in the isogonal lines, 
and though the magnetic state of the district appeal’s to be complicated, and to requme 
further investigation, we have also established several facts which will probably prove 
to be of fundamental importance in the solution of the problems connected vdth it. 
Three of the most interesting stations are Coalville (No. 76), Loughborough 
(No. 109), and Melton Mowbray (No. 116), Loughborough and Coalville are both 
on the Bed Marl, with alluvium near to the streams. Between them lies Charnwood 
Forest, in which are masses of porphyry, greenstone, and syenite. 
We should, perhaps, expect from the analogy of the Malverns that at these two 
stations the needle woidd be attracted towards the crystalline rocks. This does not 
appear to be the case, or, as is more probable, the stations are too far distant to be 
affected. At Loughborough, which is the more easterly station, the disturbance of 
the Declination is 30''3 towards the east, while at Coalville it is in the same direction, 
but only to the extent of lF’2. 
About 12 or 13 miles further to the east is Melton Mowbray, situated on Lower 
Lias clay with argillaceous limestone at its base, yet a series of observations made 
here on April 22, 1888, gave a Declination disturbance of + 32', i.e., towards the 
west. Unfortunately, the observation for the geographical meridian could only be 
made near noon, as the sun was invisible during the rest of the day; but so 
remarkable did the result appear that the place was revisited on April 30. Another 
