394 BATHYMETRICAL SURVEY OF 



The series taken in May shows a range of barely 2 from surface to 

 bottom, while the series taken in September shows a range of over 6, a 

 fall of 2 having been recorded between 90 and 100 feet. It will be 

 observed that the whole body of water was warmer in September than 

 it was in the preceding May, the bottom reading in September being 4 

 higher than the surface reading in May, while the difference between 

 the two bottom readings is about 6, and between the two surface 

 readings about 10. 



Loch Uanagan (see Plate XCVIIL). Loch Uanagan lies a little 

 more than a mile to the south of Fort Augustus, on Loch Ness. It is a 

 narrow little loch lying parallel to the Caledonian canal, which is one- 

 third of a mile to the west, and is separated from Loch Uanagan by the 

 Torr a Choiltry, a high ridge with steep sides, densely covered with fir 

 trees. This hill rises abruptly from the west side of the loch to a 

 height of 384 feet, some 266 feet above the surface of the water. 



Loch Uanagan is half a mile long, and has a maximum breadth of 

 one-eighth of a mile. The superficial area is about 25 acres, and the 

 volume of water 18 millions of cubic feet. The drainage area is about 

 1J square miles. The only stream of any size flows in at the south end, 

 and near the north end a small burn flows out to the east, where a small 

 part of the loch has been cut off by the railway, and joins the river 

 Tarff half a mile to the north. The height of the loch above sea-level 

 on July 2, 1903, was 118-2 feet. 



Loch Uanagan is very shallow, the greater part of it less than 

 10 feet deep. Only one-fifth of the area is over 25 feet in depth, the 

 25-feet contour enclosing a narrow area one-sixth of a mile long, nearer 

 to the east shore, and the maximum depth of 43 feet is near shore, the 

 slope here being steep. The steep slope of the hill on the west is not 

 continued under water, the loch on that side being shallower. 



Temperature Observations. The surface temperature on July 2, 

 1903, was 63-0 Fahr., and a serial taken at 2.30 p.m. on September 24, 

 1903, gave the following results: 



Loch Beag (by Clunie) (see Plate XCIX.). A small triangular loch 

 about a quarter of a mile west of the upper end of Loch Clunie. It is 

 simply an expansion of the river Clunie, and is at the same level as 

 Loch Clunie. It is one-third of a mile long by one-fifth of a mile 

 broad. The area of the surface is about 26 acres, and the drainage 

 area very extensive, viz. 20 square miles. The volume of water is 



