THE FBESH-WATEE LOCHS OF SCOTLAND. 
281 
From the table on p. 280 it will be seen that in the twenty-one lochs 
under consideration 2619 soundings were taken, and that the aggregate 
area of the water surface is about 18j square miles, so that the average 
number of soundings per square mile of surface is 144. The aggregate 
volume of water contained in the lochs is estimated at about 48,451 millions 
of cubic feet. The area drained by these lochs is about 30 7 J square 
miles, or nearly seventeen times the area of the lochs. 
