THE FRESH-WATER LOCHS OF SCOTLAND. 117 



or two minor undulations. The axis of maximum depth lies towards the 

 western shore, off which the slope is in places steep. The deepest part, 

 exceeding 40 feet in depth, is situated over a mile from the upper end, 

 and over half a mile from the outflow. About 28 per cent, of the lake- 

 floor is covered by less than 10 feet of water, a rather larger area (about 

 '>4 per cent.) being covered by water between 10 and 20 feet in depth. 



Temperature Observations. The following serials were taken in the 

 deepest part of the loch : 



Surface 63'4 Fahr. 



10 feet 62-8 



20 59-4 



30 58-2 



45 56-0 



The range from surface to bottom was 74, the greatest fall being one 

 of 3'4 between 10 and 20 feet. 



Loch Dungeon (see Plate XLIV.). Loch Dungeon lies about 6 miles 

 south of Loch Doon, and a similar distance east of Dairy. Hills rise 

 steeply on the south, side, and rugged crags at the west end, culminating 

 in Millfire (2350 feet) and Meikle Millyea (2446 feet). The general 

 trend is from west to east, the loch curving round a large peninsula called 

 the Point of Ringreoch. It is nearly a mile in length, with a maximum 

 breadth of a quarter of a mile, the superficial area being about 88 acres. 

 The loch drains an area of 2| square miles, the principal feeder being the 

 Hawse burn, entering near the west end, while a few minor streams flow 

 from the steep slopes of the hills to the west and south-west. The loch is 

 divided into three deep basins, the deepest situated at the west end, where 

 the slope is steepest, the maximum depth of 94 feet having been recorded 

 less than 150 yards off the western shore; the basin second in importance 

 lies at the east end, and has a maximum depth of 45 feet, while near the 

 centre of the loch is the smallest basin, having a maximum depth of 34 

 feet. About 73 per cent, of the lake-floor is covered by less than 25 feet 

 of water. The mean depth is estimated at 22 J feet, and the volume of 

 water at 87 million cubic feet. The loch was surveyed on August 6, 1903, 

 when the elevation was 1002-3 feet above the sea; a storm-beach was 

 observed 4 feet above the water, which might fall about a foot lower. The 

 southern and western shores are mostly of rock, with alluvial cones laid 

 down by the burns. The main inflow, at the west end, cuts through a long 

 sharp ridge of gravel, which abuts on the steep crags on the south, and 

 joins a ridge of rock on the north. The outflow falls several feet in about 

 100 yards, and passes first between and over boulders, and then over 

 rock. The water in the loch had a peculiar leaden or greenish-grey 

 slate colour. 



Temperature Observations. Serial temperatures taken in the eastern- 

 most basin gave identical readings of 54 C '8 Fahr. at the surface, at 10 



