372 
BATHYMETRICAL SURVEY OF 
The basin of the loch is quite simple, the deepest part being much 
nearer the north end, and the longitudinal slope is accordingly quicker 
at the north end and very gradual towards the south. The temperature 
of the water on October 18, 1904, was 46°-0 Fahr. at the surface, the 
same at a depth of 20 feet, and only a trifling fraction less at the 
bottom, 45°’8. 
PIG. 57. AN DUBH LOCHAN. 
( Photogra'ph by Colonel Mainwaring.) 
Loclian Lhnn dd-Bhrd (see Plate XC.). — A very picturesque loch, 
almost halfway between Fort William and Ballachulish. It is about 
5 miles south of Fort William, and is reached by a very rough road, 
one of General Wade’s military roads. It is a narrow loch, with its 
axis running north-east and south-west. The surrounding hills are of 
moderate height (1500 to 2000 feet) and grassy, except on the east, 
where Mullach nan Coirean rises steeply to 3000 feet. Patches of fir 
wood towards the lower end of the loch enhance the beauty of the 
scene. 
The loch is nearly a mile long and relatively very narrow, the 
greatest breadth being only about one-sixth of a mile, and the mean 
breadth one-eighth of a mile. The maximum depth is 25 feet, and the 
mean depth 8J feet. The surface has an area of about 66 acres. The 
volume of water is 23 millions of cubic feet. It receives the drainage 
