72 BATHYMETRIOAL SURVEY OF 



cover an area of about 240 acres, and the area draining into it exceeds 6 

 square miles, including Lock Eilde Beag, lying a quarter of a mile to the 

 north-east, which was not surveyed. The maximum depth of 100 feet was 

 observed near the south-west end, about 150 yards from the north-western 

 shore. The volume of water is estimated at 493 millions of cubic feet, and 

 the mean depth at 47 feet. The loch was surveyed on May 13, 1903, the 

 elevation being approximately 1110 feet above the sea. 



The contour-lines of depth coincide approximately with the outline of 

 the loch, but approach nearer to the north-western shore, off which the 

 slope is steepest. Near the north-east end there is a slight shoaling 

 covered by 70 feet of water, separating a sounding in 75 feet from the 

 main deep basin. The following table, giving the areas between the 

 contour-lines, and the percentages to the total area, indicates the general 

 regularity and somewhat flat-bottomed character of the basin : 



Feet. Acres. Per cent. 



Oto25 65 ... 27-1 



25 50 ... 64 ... 26-6 



50 75 66 ... 27-5 



Over 75 45 ... 18-8 



240 100-0 



The temperature of the surface water on the date of the survey was 

 47*0 Fahr., but serials could not be attempted on account of a heavy gale. 



From the table on p. 71 it will be seen that in the ten lochs under con- 

 sideration 570 soundings were taken, and that the aggregate area of the 

 water-surface is about 2J square miles, so that the average number of 

 soundings per square mile of surface is 228. The aggregate volume of 

 water contained in the lochs is estimated at 2067 millions of cubic feet. 

 The area drained by these lochs is 85J square miles, or 34 times the area 

 of the lochs. 



