﻿68 



MR. H. DEWEY ON THE ORIGIN OF SOME [vol. lxxii, 



The gorge commences as a vertical wall of rock, more than 

 40 feet high, and everywhere scarred with potholes. Over the 

 lip of this precipice a fine waterfall leaps clear, and carrying with 

 it its burden of stones crashes down into a large basin 40 feet 

 (see PI. VI) below, where it immediately commences drilling out 

 the rocky channel of the stream. This basin is thought to 

 resemble a miner's bowl or 'kieve,' and for this reason the locality 

 is known as St. Nectan's Kieve. 



Fig. 2. — Section through St. NectavCs Kieve. 

 The Waterfall 



ob'ft 



[Scales : horizontal, 4 inches = 1 mile ; vertical, 1 inch = 660 feet.] 

 a = The gorge. b = 430-foot plain. c = 750-foot plain. 



Fig. 3. — Section at Trevalga Mill, at a spot on fig. 1 about 

 half a mile east-north-east of St. Nectans Kieve. 



■700 ft. 



[Scales : horizontal, 4 inches = 1 mile; vertical, 1 inch = 660 feet.] 

 a = Present valley. B = 430-foot plain. C = 750-foot plain. 



The basin is breached by a hole in its side, through which the 

 waters escape and form a second small waterfall, while remnants of 

 others scar the walls of the gorge, here about 100 feet wide. The 

 stream then races among rocks through the deep ravine for several 

 miles, and thereafter forms a series of cascades and waterfalls, 

 swirling among potholes, until it reaches the sea. The sides of the 

 gorge, which is justly famed for its great charm and beauty, are 

 everywhere nearly vertical, huge crags and bluffs overhanging in 

 many parts. 



