THE FRESH-WAFER LOCHS OF SCOTLAND. 



409 



The loch is nearly 5 miles in length, has a maximum breadth of 

 nearly three-quarters of a mile, and a mean breadth of one-third of a 

 mile. It has a superficial area of 1 square miles. The volume of water 

 is subject to great variation, being estimated at the date of the survey 

 (April 24 and 25, 1903) at 1134 millions of cubic feet. It drains an area 

 of about 21 square miles. Few streams of any importance enter the 

 loch. The largest are the Allt na Seabhaig, which formerly flowed 

 into the river Gourag, but was diverted into Loch Garth when the dam 

 was built, and the Aberchalder burn, which enters the large middle bay 

 on the east. When quite full the reservoir overflows into the Gourag. 



FIG. 66. LOCH MHOR, SOUTH-EAST SHORE, WHEN THE WATER IS LOW ; ROCKS THAT 



HAVE BEEN DENUDED OF THEIR PEAT COVERING EXHIBIT GLACIAL STRIATION. 

 (Photograph by Mr. G. We*t. From " Proc. Roy. Soc. Edin.," by permission of the Council.) 



When surveyed the surface was 638-5 feet above sea-level. In accord- 

 ance with its artificial origin, the greater part of Loch Mhor is very 

 shallow ; deep water is only found in the original natural lochs. Two- 

 thirds of the whole area is less than 25 feet deep. 



The basin formed by Loch Farraline before the surface was raised 

 was fully a mile in length and one-third of a mile broad, with a depth 

 of about 40 feet. The breadth has been very little increased by the 

 dam. The depth is now 60 feet. The basin is simple, with uniform 

 contours and gently sloping sides. The 25-feet contour encloses an 

 area of two-thirds of a mile long by one-fifth of a mile broad. The 



