190 xMINERALOGY OF THE PENTLANB HILtS. 



the direction of the strata, south-west and north- 

 east ; and the dip varies from 10^ to 30'. 



It rests upon the conglomerate, as may be ob- 

 served in the course of the Logan Water above 

 Habbie's How, and appears also to alternate with 

 it, as I infer from the appearances it presents in 

 the conglomerate at the junction of the transition 

 and fl(£tz rocks, above and a little to the eastward 

 of Bevelaw House. 



It skirts the Mid-Lothian portion of the Pent- 

 land hills, from the base of the Kirkyetten Hills 

 to the south-west corner of the group, where it 

 rises several hundred feet above the neighbouring 

 country, forming the whole of the East Cairn 

 Hill. It can be traced from the base of the East 

 Cairn Hill, down the course of the Logan Water, 

 to within a few yards of the waterfall at Habbie's 

 How, and it appears to cover a considerable por- 

 tion of the high mu Irish flat traversed by the 

 Logan Water. 



III. Clinkstone, Clinkstone-Porphyry , and Amyg- 

 daloidal Clinksi one- Porphyry, 



The clinkstone, when pure, is of a deep green- 

 ish-grey colour ; but when iron-shot, which is ge- 

 nerally the case, it is reddish-brown : the lustre 

 of the principal fracture is glistening, of the cross 

 fracture glimmering : the principal fracture is 



