158 BATHYMETKICAL SUKVEY OF 



the River Spey, and immediately to the south of Loch an Eilein, into 

 which it drains. Irregular in outline, the loch trends in a south-west and 

 north-east direction, and is less than half a mile in length by one-fifth of a 

 mile in maximum breadth, covering an area of about 25 acres. The 

 maximum depth of 41 feet was recorded in a small basin at the south-west 

 end of the loch ; there is a second deep basin, having a maximum depth of 

 29 feet, lying in the wide part of the loch towards the north-east end, 

 these two basins being separated by a shoaling covered by only 4 feet of 

 water, where the outline of the loch is constricted. The volume is 

 estimated at 10 million cubic feet, and the mean depth at 9^ feet, nearly 

 three quarters of the lake-floor being covered by less than 10 feet of water. 

 The loch was surveyed on October 14, 1903, when the elevation was found 

 to be 889*3 feet above the sea, or 6 feet lower than that determined by 

 the Ordnance Survey officers in September, 1868, viz. 895'2 feet. This 

 lowering is due to the banks of the stream giving way, and consequent 

 outflow into Loch an Eilein. The surface temperature was 46'l Fahr. 



Loch an Eilein (see Plate LX.) lies about 3 miles south of Aviemore, 

 amid picturesque surroundings. At the time of the survey, a couple of 

 ospreys were nesting in the ruins of the castle on the island (see Fig. 34). 

 Somewhat crescentic in outline, the loch exceeds a mile in length, along 

 the axis of maximum depth from south-west to north-east, the maximum 

 breadth being nearly half a mile. The superficial area is about 1 30 acres, 

 and the drainage area, including Loch Gamhna, is about 2| square miles. 

 The maximum depth of 66 feet was recorded towards the south-west end, 

 and deep water occurs also near the north-east shore, where soundings in 

 51 and 47 feet were taken, the water shoaling in the central part of the 

 loch to a depth of 20 feet. The volume of water is estimated at 144 million 

 cubic feet, and the mean depth at 25J feet, 54 per cent, of the lake-floor 

 being covered by less than 25 feet of water. 



The loch was surveyed on October 14, 1903, when the elevation was 

 found to be 839*6 feet above the sea, or nearly a foot lower than that 

 observed by the Ordnance Survey officers oa September 21, 1868, viz. 

 840*4 feet above sea-level. Temperatures taken in the deepest part of 

 the loch showed a range from surface to bottom of only J Fahr. : 



Surface 49-2 Fahr. 



10 feet 49-0 



20 48-8 



30 

 40 

 50 

 60 



48.8 

 48-8 

 48-7 

 48-6 



LocJi Morlich (see Plate LXI.), the largest of the Spey lochs in super- 

 ficial area, lies in Glen More, surrounded by woods, about 4 miles east 

 of Aviemore. The loch is sub-rectangular in outline, the length from 



