THE FRESH-WATER LOCHS OP SCOTLAND. 
83 
about 65 per cent, is covered by less than 25 feet of water. The con- 
formation is simple, two soundings at the maximum depth of 45 feet 
being recorded near the middle of the loch. The loch was surveyed on the 
same day as the upper loch, the elevation being approximately 336 feet 
above the sea. The surface temperature was 56°*8 Fahr. 
From the opposite table it will be seen that in the thirteen lochs under 
consideration 855 soundings were taken, and that the aggregate area of the 
water-surface is 1’6G square miles, so that the average number of soundings 
per square mile of surface is 515. The aggregate volume of water con- 
tained in the lochs is estimated at 1828 millions of cubic feet. The 
area drained by these lochs is about 34 square miles, or 20^ times the area 
of the lochs. 
