THE FRESH-WATER LOCHS OF SCOTLAND. 115 



Surface 59-2 Fahr. 



10 feet 59-2 



20 59-2 



30 59-0 



Locli Grennocli (see Plate XLIV.). Loch Grennoch lies about 7 miles 

 south-west of New Galloway. The hills are steep and high on both sides, 

 especially to the west at the south end. Rock is exposed all round the 

 loch, with many boulders and scanty patches of vegetation. The loch 

 trends nearly north and south, and is 2 miles in length, with a maximum 

 breadth of over one-third of a mile, the mean breadth being nearly a quarter 

 of a mile. Its waters cover an area of about 290 acres, or nearly half 

 a square mile, and it drains an area of over 5J- square miles. The 

 maximum depth of 68 feet was found towards the southern end. The mean 

 depth is estimated at 21 feet, and the volume of water at 263 million cubic 

 feet. The elevation was 690'7 feet above the sea when the loch was 

 surveyed on July 24, 1903, almost identical with that observed by the 

 Ordnance Survey on September 7, 1894, viz. 690'6 feet. A drift-mark 

 was observed 3 feet above the water, which might fall a foot lower. The 

 loch forms a simple basin, the deeper water occupying the southern half ; 

 the slope is steep in places, especially off the western shore near the 

 southern end. About 70 per cent, of the lake-floor is covered by less than 

 25 feet of water. Several streams drain into the loch, the principal ones 

 being the Cuttieniore burn and the Cuttie Shallow burn, entering on the 

 western side. The Pullaugh burn, flowing out at the northern end, is 

 a broad quiet stream with a very gentle fall for a couple of miles. 



Temperature Observations. The following serial taken in the deepest 

 part of the loch showed a range from surface to bottom of only 4-2 Fahr., 

 the greatest fall being one of l-3 between 10 and 20 feet : 



Surface 60-2 Fahr. 



10 feet 59-8 



20 58-5 



30 58-0 



40 57'3 



50 56-8 



65 56-0 



Loch SJcerrow (see Plate XLIV.). Loch Skerrow lies between Loch 

 Grennoch on the west and Woodhall Loch on the east, being about 2 miles 

 distant from both, and 7 miles north of Gatehouse. The shores are 

 rocky, with numerous scattered boulders, and the islands are mostly 

 of rock, while stones are plentiful, especially towards the south ; a few- 

 small patches of yellow sand occupy the bays. The surrounding hills are 

 low and bare, with much rock exposed, and strewn with boulders. The 

 loch is subtriangular in outline, with the apex pointing south, and is 

 nearly three-quarters of a mile in length, with a maximum breadth at the 

 north end of half a mile, the mean breadth exceeding a quarter of a mile, 



