Intelligence and Miscellaneous Articles. 547 



the west formerly existed over the Weald to the south of Dorking, 

 and that the fragments now lying about the surface have been left 

 by denudation, as described by Dr. G. J. Hinde (op. cit.). Since, 

 however, as has been stated, the present Lower Greensand escarp- 

 ment to the north consists of ' sandy beds ' only, there must be 

 a lithological change from south to north (deep-water beds to 

 shallow). 



Part 2 of the paper is devoted to the district east of the Mole. 

 Where the escarpment rises above the alluvium of the river, 

 the author finds the Bargate Beds with pebbles (at Park Hill, 

 Reigate) separated from the Folkestone Sands only by a thin bed of 

 Puller's Earth and a layer of sandy chert. The section is now first 

 described ; the dip has been observed and proved, and by measure- 

 ment this pebble-bed is shown to lie at approximately the same 

 horizon above the Atherfield Clay as when it was last seen west 

 of the Mole. Prom Reigate eastwards to Tilburstow Hill the 

 same beds are seen in the numerous hollow lanes and pit-sections. 

 The pebble-beds are found approximately on a definite horizon ; but 

 whilst they become of less importance eastward, the overlying 

 cherts, first seen at Reigate, become of greater importance in that 

 direction. The thin bed of Puller's Earth, also first seen at Reigate, 

 thickens to the east likewise. 



2. l On the Eastern Limits of the Yorkshire and Derbyshire or 

 Midland Coalfield.' By W. S. Gresley, Esq., P.G.S. 



The author attempts to throw light on the question of the 

 easterly extension of the Yorkshire, Derbyshire, and Nottingham- 

 shire coalfield beneath the newer rocks. He notices the general 

 trend of the strata, the sizes of other British coalfields, the question 

 of the origin of mountains, stratigraphical considerations, and the 

 faults of the North of England. His object is rather to suggest what 

 he believes to be novel ways of treating the subject than of reaching 

 conclusions or locating limits. 



3. ' On some Phases of the Structure and Peculiarities of the Iron 

 Ores of the Lake Superior Region.' By W. S. Gresley, Esq., P.G.S. 



The author has been studying heaps of ore brought from the 

 region lying south-west of Lake Superior since 1890. He describes 

 certain structural features of the ore-fragments, and discusses the 

 evidences of mechanical movements and chemical alteration exhibited 

 by these fragments. 



LY. Intelligence and Miscellaneous Articles. 



ON ELECTROMAGNETIC TRACTIVE FORCE. BY M. WEBER. 



The author summarizes the results of his experiments as 

 follows : — 



(1) An iron wire of great length in comparison with its dia- 

 meter, one end of which is in a magnetic field parallel to the lines 

 of force, experiences a pull in the direction of its length which 

 for unit area (the square centimetre) of the cross- section is 



