THE CLYDE SEA- ARE A. 387 



Dunoon Basin a complexity of outline in its large features, contrasting with 

 the general smoothness of the shores of Loch Fyne and the Central Arran 

 Basin. The Bute Plateau has a maximum depth of 20 fathoms on its 

 shallowest line, and the Dunoon Basin deepens to 56 fathoms off Dunoon, 

 and, after shallowing, deepens again at the head to 55 fathoms at Dog 

 Rock, off the mouth of Loch Goil. 



Upper Loch Long (to which the name " Loch Long " as used in this paper 

 always refers) is simply the upper end of the Dunoon Basin, a stretch 

 8|- miles long, separated from the deep at Dog Rock by a bar rising to 

 within 18 fathoms of the surface. It has a maximum depth of 35 fathoms ; 

 it is less than half a mile wide, and is walled by very steep mountain slopes. 



Loch Goil opens into the head of the Dunoon Basin across a bar with only 

 7 fathoms of water on it. It is separated from Loch Long by the rugged 

 peninsula rising into heights of 2000 feet and more, which is named in some 

 freak of Highland humour " Argyll's Bowling Green." The loch penetrates 

 for 5 miles amongst the steepest hillsides of the whole area and preserves a 

 breadth of a little more than half a mile almost to its head. The maximum 

 depth is 47 fathoms ; and this depth, combined with the small area and 

 shallow entrance, isolates the water of Loch Goil more completely than 

 that in any other part of the area. 



The Holy Loch is only a deep bay opening into the Dunoon Basin but it is of 

 interest by occupying the mouth of the valley of the fresh Loch Eck, and 

 receiving its extensive drainage. 



Loch Striven and the eastern arm of the Kyles of Bute open to the north of 

 the Bute Plateau between Rothesay and Toward Point. Loch Striven 

 gradually tapers from its mouth to the head, unlike most of the lochs, and 

 runs for 9 miles between steep and uniform hillsides. It maximum depth is 

 42 fathoms, and its main depression crosses the opening of the Kyles and 

 cuts into the Bute Plateau. 



Where the two branches of the Kyles of Bute unite the short but very 

 picturesque Loch Riddon runs northward, forming the mouth of the long 

 valley known as Glendaruel. It is much shallowed towards the head by the 

 material brought down by the River Ruel. 



The Estuary of the River Clvde runs due westward into the Dunoon 



/ *t 



Basin between Gourock and Kilcreggan. It is everywhere shallow; depths 

 of 5 fathoms not extending further east than the line joining Greenock and 

 Roseneath Point, and on account of the narrowness of the navigable channel 

 and the great amount of traffic it has not been so minutely studied from 

 the points of view of salinity and temperature as the deeper and quieter 

 waters. 



The Oareloch is entered from the estuary, and stretches in a straight line 

 towards Loch Goil, a basin to which it presents several analogies and con- 

 trasts. It is five miles long, separated from the estuary by a bar with no 

 more than 5 fathoms on it at Row Point, which is a spit resembling that at 

 Otter. The loch is similar in outline, identical in orientation and nearly 

 equal in area and depth on the bar to Loch Goil ; but it has only half the 

 average depth of that loch and its deepest part is ouly 22 fathoms, while the 

 land bordering it is comparatively low and has the gentlest slopes that 

 surround any of the Clyde lochs. 



Loch Lomond, which discharges into the estuary by the river Leven at 

 Dumbarton, is filled with fresh water and its surface stands 24 feet above 

 sea-level ; but its configuration is exactly similar to that of the sea-lochs of 

 which, were it at sea level, it would be by far the deepest. 



The relation of the depths along the axis of the deepest water from the 

 Channel across the Great Plateau, up the eastern branch of the Arran Basin 

 to the head of Loch Fyne is shown in the accompanying section (Fig. 1), the 

 slopes of which are enormously exaggerated as the scales show : 



