CLYDE SEA AREA. 647 



Loch Goil, 3^ square miles in area, opens, like Loch Long, into the head of the 

 Dunoon Basin, and appears on the map to run in continuation of the Gareloch. It has a 

 curving outline, both coasts remaining parallel, and at first directed N.W., then N., 

 but finally N.N.W. The bar at the entrance has about 7 fathoms in the deepest part 

 (sections 7, 8, Plate VIL), and the loch is contracted to about half its average width, 

 which is three-quarters of a mile. The length, measured along the central line, is 5 miles, 

 and the greatest depth (47 fathoms) occurs 3f miles from the mouth, or three-quarters of 

 the way to the head of the loch. The mountain-wall investing this basin is the steepest 

 and highest in the Clyde Sea Area, and the torrents which leap down the bare rocky 

 sides hurry almost the entire rainfall of the slopes into the water. The area is small — 

 3^ square miles ; but the drainage area is comparatively extensive — 34 square miles. 

 The volume at low tide is 0*037 cubic sea mile, and at high tide 0*004 more. The low 

 tide mean depth along the axis is 30^ fathoms, and the average depth over all 14 fathoms. 

 As in Loch Long, the upper end has been greatly silted up. The river-borne debris 

 forms a remarkably steep talus at the head, over which the river is gradually encroaching 

 on the deep basin by rolling silt down the slope in the manner of a railway embankment. 

 For 2 miles inland i from the head of the loch the stream winds through a flat valley less 

 than a mile wide, and limited by steeply rising mountain slopes. This irresistibly 

 suggests that it is the old bed of the loch, reclaimed by the river and elevated by the 

 last great land movement which bordered Scotland with a line of raised beaches. 



The Holy Loch is an inlet 1\ miles long, running N.W. by W. parallel to the lower 

 part of Loch Goil. It occupies the mouth of a long inland valley which runs on the 

 whole N.N.W. for 16 miles right across to Loch Fyne, its highest point being 173 feet. 

 The middle of this valley is occupied by Loch Eck, 67 feet above the sea, 6 miles long, 

 and about a quarter of a mile wide, running parallel to the general direction of Loch Goil. 

 The Holy Loch looks straight up the estuary across the deep trough of the Dunoon Basin, 

 on which it opens at right angles. The depth decreases gradually from the mouth of 

 the loch toward the head, where it shoals with extraordinary abruptness, the silting up 

 at the head being like that at Loch Goil, but more pronounced, as the larger Biver 

 Echaig, carrying the overflow of Loch Eck, enters through a flat-bottomed clayey valley. 

 This valley may be compared to a great barrier raised above the water-level, so as to cut 

 off what might at one time have been a sea-loch. The area of the Holy Loch is only \\ 

 square miles, and into this is carried the drainage of 72 square miles of country. The 

 volume of water in Holy Loch at low tide is about 0*01 cubic sea mile, and at high 

 water 0*0016 more; the average low- water depth is %\ fathoms. Loch Eck lies in a 

 steep narrow cleft of the hills, its maximum depth, as far as I could judge from a hasty 

 survey made in August 1889, is 25 fathoms If miles from the head. Its area is \\ 

 square miles, and the surrounding drainage area is 38 square miles. The loch is famous 

 for rising rapidly after rain ; it is stated that a rise of 2 feet between the morning and 

 afternoon of a very rainy day has frequently been noticed. This would correspond to a 

 fall of 1 inch of rain over the entire area, and is probably an exaggeration. 



