THE FRESH- WATER LOCHS OF SCOTLAND. 363 



veying the overflow to the east loch. The long narrow loch is nearly 

 straight. From the centre it narrows to the outflow, but southwestward 

 to the upper end the width is nearly uniform, the end rectangular, 

 straight, and a quarter of a mile across. 



The basin is quite simple, none of the contour lines being broken. 

 The contours do not closely follow the shore-line ; they narrow more 

 decidedly than the outline from the centre to each end, the slopes being 

 much steeper towards the centre of the loch, where the sections are 

 U-shaped. The deepest part is rather to the east of the centre, and 

 it is curious to note in close proximity an elevation with only 30 feet 

 on it, surrounded on all sides by water exceeding 50 feet in depth. 



The approximate areas between the contour-lines, and the per- 

 centages to the total area of the loch, are as follows : 



to 25 feet 102 acres 38 '7 per cent. 



25,, 50 ,, 85 ,, 32-2 



50,, 75 67 25-6 



Over 75 9 3'5 



263 , 100-0 



Temperature Observations. A series of temperatures at the deepest 

 part of the loch showed a range of 4-8 Fahr. from top to bottom. The 

 greater part of this was in the upper 10 feet, the difference between 10 

 and 60 feet being only 1, as shown in the following table : 



Surface 49'9 Falir. 



10 feet " ... ... 46-l 



20 45-8 



60 45'l 



Near shore the surface temperature was as high as 53'4. 



The East Loch. This is about half a mile distant from the west 

 loch, and nearly 10 feet lower, about 1140 feet above the sea. It is 1J 

 miles long, a quarter of a mile in greatest breadth, and averages just 

 under one-fifth of a mile in breadth. The maximum depth is 69 feet, 

 and the mean depth 31 feet. It has an area of about 146 acres, or nearly 

 a quarter of a square mile, and it drains an area extending to about 9^ 

 square miles, including that draining into the west loch. The volume 

 of water is 191 millions of cubic feet, or less than half the volume of the 

 west loch. The chief feeder is the stream from the west loch. There 

 enters also at the upper end a branch of the Allt na Magha, the stream 

 which has laid down the delta now separating the two lochs. About the 

 middle of the east shore enters the small stream coming from Loch an 

 lubhair. The waters of Lochan na h-Earba are discharged by the Allt 

 Lowrag, about a mile long, into Loch Laggan. 



The east loch has the same general form as the west loch, long and 

 narrow, broader at the upper end and tapering to the outflow. The 



