THE F1M-:>U- \\.\TKR LOCHS OF SCOTLAND. 



73 



twenty-nine times greater than that of the loch. Over 100 soundings 

 were taken in Loch Lyon, the maximum depth observed being 100 feet. 

 The volume of water contained in the loch is estimated at about 

 460,750,000 cubic feet, and the mean depth at 45 feet, or 45 per cent, 

 of the maximum depth. The length of the loch is 92 times the maximum 

 depth, and 205 times the mean depth. As stated, the loch forms a 

 simple basin, the bottom sinking gradually on all sides towards the 

 deepest part, which is approximately centrally placed. The deep water, 



FIG. 21. LOCH LYON. 



(Photograph by Sir John Murray.) 



however, approaches much closer to the south-west end than to the 

 north-east end, where the 25-feet line is distant about a quarter of a 

 mile from the shore, probably through silting up of the lake-floor at that 

 end. The 25-feet basin is nearly 1 miles in length, the 50-feet basin 

 is about 1J miles in length, and the 75-feet basin is about 1J miles in 

 length. The area of the lake-floor covered by less than 25 feet of water 

 is about 92 acres, or 39 per cent, of the total area of the loch ; the area 

 between the 25- and 50-feet contour-lines is about 36 acres, or over 

 15 per cent. ; the area between the 50- and 75-feet contours is about 



