THE FRESH-WATER LOCHS OF SCOTLAND. 



LOCHS OF THE NAIRN BASIN. 



THE three lochs within the Nairn basin (see Index Map, Fig. 19) that 

 were sounded by the Lake Survey are situated in Inverness-shire at the 

 head of the river, over 20 miles to the south-west of the town of Nairn, 

 and comparatively close to the eastern shore of Loch Ness, being, indeed, 

 sandwiched between Lochs Ashie and Ruthven of the Ness basin. They 

 form a connected series, Loch Ceo-Glas flowing into Loch Dun na Seil- 

 cheig, the most important of the series, and thence into Loch a' Chlachain. 

 They all contain trout, and Loch Dim na Seilcheig also contains char, but 

 the fishing in it is preserved. 



Loch Ceo-Glas (see Plate LXIV.) lies about 11 miles south of Inver- 

 ness, and only a mile and a half from the eastern shore of Loch Ness, 

 opposite Urquhart bay. Elongate in form, it trends in a south-west and 

 north-east direction, and is nearly a mile in length, though the maximum 

 breadth is only about one-seventh of a mile, the superficial area being 

 about 54 acres. The northern portion of the loch is shallow, with the 

 deeper water in the southern half, the maximum depth of 32 feet having 

 been recorded little more than a quarter of a mile from the southern end, 

 and towards the western shore, which is bordered by vertical and over- 

 hanging cliffs. The volume of water is estimated at 24 million cubic feet, 

 and the mean depth at a little over 10 feet. Nearly two-thirds of the lake- 

 floor is covered by less than 1 feet of water. The loch was surveyed on 

 May 1, 1903, when the elevation was found to be 762-9 feet above the sea, 

 or a foot lower than the level observed by the Ordnance Survey officers on 

 March 2*, 1S71. Temperatures taken in the deepest part of the loch 

 showed that the water was nearly uniform in temperature from surface to 

 bottom, the readings being : f 



Surface 46'3 Fabr. 



10 feet 46-2 



20 46'l 



30 ... 46-0 



Loch Dun na Seilcheig (see Plate LXIV.). Loch Dim na Seilcheig 

 (or Duntelchaig) is a large and deep loch lying about half a mile to 

 the north-east of Loch Ceo-Glas, the difference in level being about 

 60 feet, Somewhat irregular in outline and variable in width, the loch 

 trends in a south-west and north-east direction, and is nearly 3J miles 



