THE FRESH-WATER LOCHS OF SCOTLAND. 17 



thus falls below sea-level, as indicated on Plate X. The cubic mass of 

 water contained in the loch is estimated at 562,000,000 cubic feet, and 

 the mean depth at 19| feet, or 26 per cent, of the maximum depth. 

 The length of the loch is 110 times the maximum depth, and 427 times 

 the mean depth. 



The bottom of the Lake of Menteith is apparently very irregular. 

 The 10-feet line follows approximately the outline of the loch, except 

 that it is considerably removed from the south and south-east shores, 

 where the land is bordered by reeds; it also surrounds the islands of 

 Inchmahome, on which the Priory is situated, and Inch Talla, on which 

 the castle is situated. Dog Isle, and a submerged crannog covered by 



FIG. 11. LAKE OF MENTEITH. 



(Photograph by G. W. Wilson.) 



four feet of water in the north-eastern angle of the loch at Port of 

 Menteith. The area of the bottom covered by more than 25 feet of water 

 is cut up into three portions. The eastmost of these 25-feet depressions 

 has a maximum depth of 48 feet ; the central 25-feet depression is almost 

 triangular in outline, with a maximum depth of 49 feet. The westmost 

 25-feet depression is the largest and the deepest : it is almost divided 

 into two halves by a narrow constriction between Inch Talla and Stable 

 Point, the deepest water observed in the southern half being 49 feet, 

 while the northern half contains the deepest water found in the loch. 

 Here the bottom falls below the depth of 50 feet over an area of nearly 

 32 acres, the 50-feet depression being about a third of a mile in length 

 and over a sixth of a mile in maximum width. It encloses a small patch 



c 



