262 BATHYMETRICAL SURVEY OF 



LOCHS OF THE CLYDE BASIN. 



WITHIN this basin (see Index Map, Fig. 27) seven lochs were sounded 

 by the Lake Survey staff, including one of the largest and most important 

 of Scottish fresh-water lochs (Loch Lomond), which is interesting as being 

 one of the two Scottish inland bodies of water surveyed " in the interests of 

 navigation" by officers of the British navy so long ago as 1861. The other 

 loch surveyed at that time was Loch Awe in the Etive basin, to be dealt 

 with later. With the object of determining what changes in conformation, 

 if any, had taken place in the interval of over forty years, Loch Lomond 

 and Loch Awe were sounded in 1903, and the results were carefully com- 

 pared with those obtained in 1861, as shown in the Admiralty charts 

 published in 1862 and 1863 respectively. Generally speaking, the depths 

 recorded by the two surveys, both in Loch Lomond and in Loch Awe, 

 agree very closely, and it was at first considered that it would be 

 unnecessary to publish the soundings in these lochs, but ultimately the 

 Directors decided, in order to render the account of the work of the Lake 

 Survey complete, to issue the maps of these lochs in the same form as the 

 other maps accompanying this volume. 



To the north of the Firth of Clyde, besides Loch Lomond, two neigh- 

 bouring small lochs (Geal and Sloy) were sounded, and to the south of the 

 Firth of Clyde, four lochs were sounded, viz. Kilbirnie Loch, Castle 

 Semple Loch, Loch Thorn, and Gryfe reservoir, the two last mentioned 

 being artificial, and connected with the supply of water to the town of 

 Greenock. 



Loch Lomond (see Plates CXXIV. and CXXV.). Loch Lomond is so 

 well known that there is no necessity to enter here into a detailed topo- 

 graphic description ; the beauty of its surroundings, which is enhanced by 

 the many large islands occupying the wide southern portion, has been 

 referred to by many writers, and has earned for it the title of " Queen of 

 Scottish lakes " (see Fig. 35). Briefly, it may be stated that the loch 

 trends nearly north and south, and in a straight line is about 21 miles in 

 length, but following the sinuous axis of maximum depth, the length is 

 nearly 23 miles, Loch Lomond being exceeded in this respect only by 

 Loch Awe and Loch Ness. The upper northern portion for a distance of 

 12 or 13 miles from the head of the loch is narrow, mostly less than a 

 mile across, but to the south of ROBS point the loch opens out, and attains 



