150 COAL-FIELD OF CLACKMANNANSHIRE. 



and impressions of trees ; and in the beds ad- 

 joining these, bivalve shells of the My a genus 

 are found* 



We have to remark, that when coals and their 

 accompanying strata, are found in a situation alto- 

 gether vertical, or nearly so, adjoining primitive or 

 transition mountains, the coals, with their accom- 

 panying strata, sometimes for a considerable dis- 

 tance, run in a line exactly parallel with the face 

 of the mountains ; and the beds of coal appear to be 

 of a true tabular shape, lying evenly or straight 

 within their bounding planes, as is clearly exempli- 

 fied in the Edge-coals, which stretch along the 

 south side of the Pentland Hills, in the vicinity of 

 Edinburgh. We have, however, strong reasons for 

 concluding, that this tabular form of these beds of 

 coals, extends only in a limited longitudinal direc- 

 tion, conforming with the face of the mountains ; 

 for, after many examinations of the strata of the 

 Mid-Lothian coal-field, I am led to conclude, that 

 these edge-coals, at the depth of several hundred 

 yards from the surface, deflect or bend southward 



* In making my investigations of this most interesting dis- 

 trict, I was greatly aided by the very polite attention of Fran- 

 cis Downing, Esq. who not only gave me every facility in 

 viewing the mines of coal and of limestone, but communicated 

 to me in the most liberal manner, every information connected 

 with my inquiries. It is to him I am indebted for the accurate 

 sections of this mineral field. 



