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APPENDIX. 
A Report on Magnetic Disturhances in Northamptonshire and Leicestershire 
and their Relations to the Geological Structure. 
By Arthur Hubert Cox, M.Sc., Ph.D., F.G.S. 
{Draivn up at the Request of the Iron-ore Committee of the Conjoint Board of 
Scientific Societies.) 
Received July 5, 1918. 
[Plates Ap. 1-Ap. 3.] 
Contents, 
Page 
Introduction—History of the Research. 74 
Method of Procedure.76 
Part 1.—The Magnetic Observations, by G. W. Walker. 78 
Part II.—On the Magnetic Susceptibilities of Certain Rock Specimens, by Ernest Wilson. . 83 
Part III.—The Geological Structure and the Magnetic Disturbances, by A. H. Cox .... 87 
(A) Northamptonshire ; Irthlingborough District— 
I. The Geology of the District.88 
II. Interpretation of the Results. 90 
III. The Underground Structure. 92 
IV. Summary. 93 
(B) Leicestershire : Melton Mowbray District— 
I. The Geological Sequence and Structure.94 
1. The General Succession. 94 
2. Rocks above the Coal Measures.96 
3. The Deep-seated Geology. 98 
4. The Igneous Rocks.101 
II. The Relative Magnetic Susceptibility of the Rocks.103 
1. The Sedimentary Rocks.103 
2. The Igneous Rocks.105 
3. Summary.109 
VOL. CCXIX.—A. L 
