THE FRESH-WATER LOCHS OF SCOTLAND. 
411 
Dun na Seilcheig and Huthven, and draining into the latter. Low 
but craggy hills border the loch on the west and north, the crags of 
Creag Dearg facing the west end. The loch is of somewhat oblong 
form, with the long diameter east and west. The length is nearly 
two-thirds of a mile, the greatest breadth one-third of a mile, the mean 
breadth one-fifth of a mile. The superficial area is about 86 acres, and 
the volume of water 103 millions of cubic feet. The drainage area 
is nearly one square mile. Only one stream, the Allt Bhreac, flows 
in on the north, and at the east end the burn flows out towards Loch 
Ruthven. 
Loch a’ Choire is 865 feet above the sea. The bottom forms a simple 
basin, with the deeper water towards the east end. The 25-feet contour 
follows the shore-line, except at one point on the north, where a sounding 
of 18 feet lies far out. The 50-feet area, one-sixth of a mile in length, 
lies all to the east of the centre of the loch. The maximum depth is 60 
feet, and the mean depth 27^ feet. The temperature at the surface on 
April 28, 1903, was 43°-5 Fahr. ; at 25 feet, 42°-5 ; and at 50 feet, 42°-5. 
Loch Ruthven (see Plate CV.). — A loch of fair size, some 2J miles 
east of Loch Ness, opposite Urquhart bay, and half a mile south of 
Loch Dun na Seilcheig. It is a narrow loch, with its central line 
much curved, but having its general direction east to west. Precipitous 
wooded hills, the Tbrr Mbr and the Torr Beag, rise abruptly from the 
north shore. On the south the crags of Stac Gorm and Craig Ruthven 
border the eastern part of the loch, while towards the west the ground 
is lower and more open. 
Loch Ruthven is very narrow in the middle, slightly expanded at the 
east, and much expanded at the west end. The length is 2J miles, the 
maximum breadth, close to the lower end, fully half a mile, and the 
mean breadth a quarter of a mile. It has a superficial area of about 
368 acres, or over half a square mile, and a volume of 180 millions of 
cubic feet. The drainage area is 4 square miles. The burn from Loch 
a’ Choire comes in near the upper end of the loch, and there are no 
other burns of any size. The outflowing stream is the river Farigaig, 
which falls into Loch Ness at Inverfarigaig. 
When surveyed on April 27 and 28, 1903, the loch was 2 feet below 
a bench-mark, 703 T on the south shore at the upper end, and would 
therefore be 70 IT feet above the sea. This figure is at variance with 
two spot-levels on the north shore, where 687 and 688 feet are marked 
near the west end, and there is no dam to account for so much difference. 
The Ordnance Survey, on May 8, 1871, made the level 700*4 feet, only 
a few inches lower than our measurement. Loch Ruthven is on the 
whole very shallow, having a mean depth of only 11 feet. The small 
eastern expansion has a flattish sandy bottom, with a greatest depth 
of 8 feet. 
