156 Intelligence ana Miscellaneous Articles. 



invariably indicates a distinct horizon, we also find the casts of 

 shells, rarely or never met with in the "West of England, but which 

 appear common in some parts of the Continent — e. g. species of 

 Isoarca, a certain form of Opis, which latter occurs also in a portion 

 of the Yorkshire Basin (V.). This bears 130 miles X. by W. from 

 the reef at Upware. The Corallian beds are grouped as a belt of rocks 

 enclosing an oval tract of Kimmeridge Clay. There is more sym- 

 metry here than in the south ; and the triple division of grit, lime- 

 stone, and grit, though not absolutely true in all places, is fairly 

 accurate ; most of the beds are better- developed, and the contrast 

 between the Coral Iiag and underlying Oolites is strongly marked. 

 In the Tabular Hills these Oolites constitute a double series, divided 

 by a " Middle Calc Grit," a fact first indicated on stratigraphical 

 grounds by Mr. Fox Strangways, and amply borne out by fossil 

 contents. The shell beds of the Lower Limestones are, especially 

 in their lower parts, charged with Brachiopoda and other forms of 

 the Lower Calc Grit ; whilst the Upper Oolite, on which the Coral 

 Rag reposes, contains a far more varied fauna, though singularly 

 destitute of Brachiopoda. The fauna of the Iiag here, as elsewhere, 

 inclines to Kimmeridgian types. 



As the object of the paper was to arrange facts rather than to 

 propound theories, the conclusion was chiefly occupied in summing 

 up and correlating. It was shown that, since the leading feature 

 of the rock masses between the Oxford and Kimmeridge Clays is 

 variety, a strict and rigid correlation is altogether impossible. Yet, 

 in spite of great local differences, producing in many places a 

 strangely contrasted facies, there are certain features which may be 

 deemed fairly characteristic of the several divisions. The bank- like 

 character of most of these beds was insisted upon. A table of com- 

 parative sections, 14 in number, affording a generalized idea of the 

 development, was exhibited, and the stratigraphical verifications of 

 many of these given, as sections drawn to scale, in the body of the 

 paper. 



XXIII. Intelligence anal Miscellaneous Articles. 



BY PROF. M. AVENAMUS. 



rFHE 'Philosophical Magazine' for 1876, No. 14, contains a 

 ■*- treatise by Mr. Oliver J. Lodge, in which (p. 543) the author 

 says that the electromotive force of a thermo-element is expressed 

 by the formula B£by(0;-O a ){e o -J(e x + e a )|, . . . . (1) 



in which y represents a constant, 6 1 and 2 the temperatures of the 

 junction-places, and ti Q the temperature of the neutral points. He 

 here remarks, " The law was originally given nearly in this shape 

 by Avenarius ; but he omitted the two Thomson effects, and con- 

 sequently his formula was erroneous " (here Mr. Lodge cites Pogg. 

 Ann. vol. cxix. 1863). 



In the first place, the expression which I used respecting the 

 electromotive force of a thermo-element is not approximately re- 



