68 Cambridge Philosophical Society. 



boundary must^be than is represented by Farey. Mr. H. stated that 

 he should be much surprised if, on completing his investigations, 

 he should find any fault coextensive with that boundary. 



Mr. H. proceeded to describe the curious formation of the valley 

 of the Wye, and the striking parallelism of the numerous faults in 

 its vicinity. These faults follow the same law as the principal mi- 

 neral veins in this district, forming themselves in many cases rake 

 veins of this description. Mr. H., in fact, considers these faults and 

 veins to be phenomena of one class, and consequently that they are 

 to be referred to the same mechanical cause. Now he conceives that 

 faults such as those described may be shown to be, if not the ab- 

 solutely necessary, at least the very probable consequences of those 

 forces which are believed by geologists to have produced general 

 elevations of the strata, ( as distinguished from merely local ones, with 

 which faults are connected,) similar to that observable in the lime- 

 stone of Derbyshire. Hence he believes that those fissures also 

 which in the limestone so frequently become mineral veins, are re- 

 ferrible to the same general elevating forces just alluded to. Of 

 the truth of this opinion, Mr. H. stated, that he believes he shall 

 be able to offer much stronger evidence than has yet been brought 

 forward. 



This communication led to various observations from several of 

 the Members present. 



A Meeting was also held on Thursday, December 5, Dr. Clark be- 

 ing in the chair. Professor Farish gave an account of a large me- 

 teor of the nature of a falling star, which he observed on the 10th 

 of September last. Professor Sedgwick afterwards gave an account 

 of the results of his examination of Charnwood Forest, in Leicester- 

 shire, in the course of the last summer. The communication was 

 divided into three parts. 



In the first part were considered the relations of the Forest rocks 

 to those of the neighbouring districts. The phenomena were illus- 

 trated by sections. It was shown, that the coal fields on the west 

 side of the Forest were under the new red sandstone ; that the Forest 

 is almost surrounded by a plain of red marl and sandstone, resting 

 unconformably on the edges of the older strata ; and that the lias 

 and inferior oolites overlie the red marl in regular order, forming a 

 remarkable feature on the east side of the county. Hence the 

 author asserted, that the works carried on at Billesdon Coplow in 

 search of coal, had been undertaken in entire ignorance of the stra- 

 tification of the country; and that in a published report by a mi- 

 neral surveyor, the marlstone and lower oolites (though lying over 

 the regular lias terrace and full of fossils,) had been mistaken for 

 the new red sandstone. 



In the second part the author described the rocks of the Forest, show- 

 ing them to be composed of greenish slate (like the great middle group 

 of Cumberland), alternating with, and seeming to pass into, great ta- 

 bular masses of porphyry and compact felspar. It was stated that the 

 porphyry abounded at the N.W. corner of the district, almost to the 



