384 Correspondence — A. Strahan — C. Daoies Sherhorn. 

 GOE-iaiESiPOisrjDEiNrGJB:. 



BALA LAKE AXD THE KIVER SYSTEM OF NOETH WALES. 



Sir, — In the July number of the Geological Magazine, Mr. Lake 

 refers to my criticism on his paper on Bala Lake and the Eiver 

 System of North Wales (Quart. Journ. Geol. Soc, vol. Ivi, p. 231). 

 I take this opportunity of stating that one part of that criticism was 

 based on a misapprehension. I understood from hearing the paper 

 read that Mr. Lake considered that great earth-movements had taken 

 place since the deposition of the glacial drift. On reading the paper 

 in the Geological Magazine, I see that I was mistaken, and I wish 

 to assure Mr. Lake of my regret at having misunderstood his views 

 on this point. 



I am obliged to Mr. White for pointing out an inaccurately worded 

 allusion to the Vale of Pewsey. The river, as he states, rises on 

 Cretaceous and not on Oolitic rocks. My point, however, was 

 to show that this and certain other rivers flow eastward, or join 

 the eastward flowing system, against the general run of the country. 

 Locally no doubt the direction of the drainage was affected by folds 

 as suggested by Mr. White. A. Strahan. 



Swansea, July 14, 1902. 



GEOLOGICAL SOCIETY OF LONDON: LAKE y. STEAHAN. 

 Sir, — I think the ventilation of this matter highly desirable. 

 Mr. Lake has, however, made one mistake in his letter. In his 

 last sentence he surely means " Eeferee system of the Geological 

 Society," and not " Burlington House." C Davies Sherborn. 



Addendum. — In Mrs. M. M. Ogilvie Gordon's paper " On Monzoni 

 and Upper Fassa," which appeared in the July number of this 

 Magazine, the four names of places marlted by arrows above the 

 transverse section given on p. 310 were accidentally omitted by us, 

 which we greatly regret. The section with the names inserted is 

 repeated below. — Edit. Geol. Mag. 



Sella. Costabella. CampagEazza. Pellegrino. 



£,W. / ,s 



Transverse section through the Costabella range (Middle Triassic limestone) ; the 

 Campagnazza Meadowland (Lower Triassic mixed deposits and fault -fragments 

 of Permian strata) ; the slopes of Pellegrino Valley (Permian strata (Pm.) and 

 Quartz PorphjTj (Q.P.)) ; //, 'Asta' faults; H.JF., old east-Avest fault; 

 s s, porphyrite sill and dyke system ascending faults, cleavage -planes, and 

 hedding-planes. 



