Mr. BRYCEon the Geological Structure of Roseneath. 113 



transmitted every minute, or as fast as they can be read, by means^^of 

 Mr. Mitchell's invention. The working of the instrument was highly 

 satisfactory. The ease, precision, and unerring accuracy with which it 

 can be wrought, were made apparent to all present. 



A2yril nth, 1850. — Mr. Liddell in the Chair. 



The Society appointed Mr. Harvey, Mr. Gourlie, and Mr. Keddie to 

 represent the Society at the Meeting of the British Association, to be 

 held in Edinburgh in August next. 



Mr. Bryce gave the following outline of the Geology of the Peninsula 

 of Roseneath, and the adjoining tracts: — 



XV. — On the Geological Structure of the peninsula of Roseneath and the 

 adjoining parts of Renfreio and Argyle. By James Bryce, Jun., 

 M.A., F.G.S. 



I. — Introduction. 



1. In a paper which I had the honour to lay before the Society two 

 years ago, on certain peculiarities in the geology of Bute, I promised, on 

 a future occasion, to call the attention of the members to some analogous 

 strata further up the Frith, which I had not then examined with sufficient 

 care. They seemed to possess considerable interest; and on a more 

 careful inspection of them I have not been disappointed. I propose to 

 state briefly, in this communication, a few of the facts most worthy of 

 being put on record. 



TI. — Roseneath. 

 a. Primary Strata. 



2. The peninsula of Roseneath forms the south-western portion of the 

 county of Dunbarton. It is bounded on the south by the frith of Clyde, 

 and has the Garoloch and Loch Long on the east and west. It is eight 

 miles long, and the breadth varies from one and a-half to two niUes. It 

 consists of a single irregular ridge of hilly ground, which runs through its 

 whole length, scarcely reaching the height of 1000 feet, and declining with 

 a nearly equal slope toward either estuary. In the northern part the rocks 

 near the summit of the ridge rise into detached craggy knolls, presenting 

 steep and bold fronts towards Loch Long; while the central and southern 

 portions exhibit none of those rugged or serrated forms, which give a 

 highly picturesque character to the adjoining tracts. But, although of 

 such inferior elevation, and itself devoid of any remarkable feature, this 

 ridgo affords a series of more beautiful and striking prospects in every 

 direction, than perhaps any part of the varied shores of our great 

 western frith. 



Vol. III.— No. 2. 4 



