THE HIGH FORCE, TEE3DALE. 471 



dence to the contrary ; and I have very little doubt that the more 

 the country is worked over the more and more evident will the in- 

 trusive character of the whin sill become. 



P.S. Since the above was written, Mr. F. Rutley has kindly cut, 

 and microscopically examined, sections of the rocks a, b, and c of the 

 High-Force section (vide supra) ; and the results obtained entirely 

 confirm my statements : a and c are basalts ; and b is evidently an 

 altered sedimentary rock. The examination of the rocks in the field 

 really left no doubt on this head. 



