THE FRESH- WATER LOCHS OF SCOTLAND. 95 



Garry between Struan and Blair Atholl. It contains fine trout, but the 

 fishing is strictly preserved. It is surrounded by low, heather-clad hills, 

 which slope gradually up from the shores of the loch. There are few 

 weeds, and the bottom is sandy, or (in parts) gravelly. Loch Bhac 

 trends in a north-east and south-west direction, and is extremely simple 

 in outline and in conformation. It is over one-third of a mile in 

 length, and one-sixth of a mile in maximum breadth, the mean breadth 

 being over one-eighth of a mile, or 33 per cent, of the length. Its 

 waters cover an area of about 31 acres, or one-twentieth of a square 

 mile, and it drains an area thirty-six times greater, or nearly 2 square 

 miles. About 30 soundings were taken, the maximum depth observed 

 being 42 feet. The volume of water contained in the loch is estimated 

 at 22,104,000 cubic feet, and the mean depth at 16J feet, or 39 per cent, 

 of the maximum depth. The length of the loch is 48 times the maximum 

 depth, and 122 times the mean depth. Loch Bhac forms a simple basin, 

 the bottom sloping gradually down on all sides to the deepest part, 

 which is approximately centrally placed, but rather nearer to the 

 southern end and to the eastern shore, where the slope of the bottom is 

 steeper than at the northern end and off the western shore. The area 

 of the lake-floor covered by less than 10 feet of water is about 16 acres, 

 or 51 per cent, of the entire area of the loch; that covered by water 

 between 10 and 25 feet in depth is about 8 acres, or 25 per cent. ; and 

 that covered by more than 25 feet of water is about 7 acres, or 24 per 

 cent, of the total area of the loch. Loch Bhac was surveyed on July 6, 

 1903, but the elevation of its surface above the sea could not be deter- 

 mined from bench-mark, though from a spot-level at the north end of 

 the loch it is apparently slightly under 1070 feet. The water rises and 

 falls very little, the range being probably less than 1 foot. On 'com- 

 mencing the survey at 6.15 p.m., the temperature of the surface water 

 was 53-0 Fahr., and in the centre of the loch a little later readings at 

 the surface, at 25 feet, and at 40 feet gave identical results, 45'0. 



Loch Con (see Plate XXVIII.). Loch Con (Chon, or Choin) lies 

 to the east of Loch Garry, and flows by the Allt Choin into Erochy 

 water, which joins the river Garry at Struan. It was formerly a good 

 trout loch, but now contains many pike, which are supposed to have 

 been maliciously introduced. Its gradually sloping shores are heather- 

 clad, with few large boulders.* There are trees on the islands and on the 

 promontory at the west end. The outflowing burn goes through a large 

 flat mass of moraine debris, which extends far down the burn. The loch 

 trends in an east and west direction, and is extremely irregular in 

 outline, being almost divided into two portions by a narrow constriction 

 near the middle. It is nearly a mile in length, and over a quarter of 

 a mile in maximum breadth, the mean breadth being over one-tenth of 

 a mile, or 11 J per cent, of the length. Its waters cover an area of about 



