THE FRESH- WATER LOCHS OF SCOTLAND. 171 



THE LOCHS OF LISMORE. 



THE Island of Lismore (see Index Map, Fig. 5), lying at the junction of the 

 Firth of Lome with the Sound of Mull and Loch Linnhe, some 5 miles north- 

 west of Oban, is a long narrow island less than 10 miles in length, trending 

 from south-west to north-east, and includes three small lochs which were 

 sounded by the Lake Survey, viz. Lochs Baile a' Ghobhainn, Kilcheran, 

 and Fiart. These lochs trend generally in the same direction as the 

 island, Loch Baile a' Ghobhainn lying towards the northern end, while 

 the other two are situated towards the southern end, Loch Fiart, the 

 southernmost, less than 2 miles from the southern extremity of the island. 

 The island is on the whole flat, the highest point, Barr Mor, between 

 Lochs Fiart and Kilcheran, being only 417 feet above sea-level. The 

 lochs, though small (one-half to two-thirds of a mile in length), are 

 relatively deep, all exceeding 50 feet in depth, the deepest, Baile a' 

 Ghobhainn, having a depth of 88 feet ; they contain trout, but the fishing is 

 preserved. The water of the lochs is impregnated with lime derived from 

 the limestone formation of the island, and the plants become thickly 

 encrusted with it ; sometimes MyriophyUum spicatum becomes so weighted 

 with lime that the plants are prevented from rising to the surface, and in 

 consequence do not bear fruit. 



Loch Baile cC Ghobhainn (see Plate LXV.). Loch Baile a' Ghobhainn 

 (or Balnagowan) is the largest of the three lochs in all respects, but 

 its drainage area is very small. The loch is widest and deepest in the 

 southern portion, narrowing and shallowing gradually towards the northern 

 end. The stones and reeds around the margin are thickly encrusted with 

 lime. The length is two-thirds of a mile, and the superficial area about 

 33 acres. The maximum depth is 88 feet, the mean depth nearly 39 feet, 

 and the volume of water 55 million cubic feet. The soundings show that 

 Loch Baile a' Ghobhainn forms a simple deep basin with steep shore- 

 slopes; gradients exceeding 1 in 1 were observed off the western shore 

 towards the southern end, where soundings in 61 feet and 22 feet were 

 recorded about 60 feet and 10 feet respectively from the shore, and off the 

 eastern shore, towards the northern end, where a sounding in 44 feet 

 was recorded about 30 feet from shore. The two ends of the loch are 

 comparatively shallow, and hence 41 per cent, of the lake-floor is covered 

 by less than 25 feet of water, but the deep basin partakes of a flat-bottomed 

 character, since over 17 per cent, of the lake-floor is covered by more than 



