THE FRESH-WATER LOCHS OF SCOTLAND. 313 



on the date of the survey the sun could not be seen, except by going 

 over to the north-west shore. The two lochs trend in a north-east and 

 south-west direction, and together have a total length of 4f miles. 

 Loch a' Bhealaich exceeds 1| miles in length, with a maximum breadth 

 of a quarter of a mile. Its waters cover an area of about 175 acres, 

 or over a quarter of a square mile, and it drains an area of nearly 6 

 square miles. The maximum depth of 80 feet was observed towards 

 the north-east end of the loch. The volume of water is estimated at 

 238 million cubic feet, and the mean depth at over 31 feet. The loch 

 was surveyed on October 17, 1902, when the elevation of the lake- 

 surface was found to be 572-2 feet above sea-level. The water might 

 rise 2 or 3 feet above, and fall about 1J feet below, that level. 



The main body of Loch a' Bhealaich is quite simple in conformation, 

 but at the north-east end there is a small expansion of the loch, having 

 a maximum depth of 14 feet, separated from the main body by a 

 constriction in which the depth is 9 feet. The 25-feet area is over a 

 mile, and the 50-feet area over half a mile, in length, the deeper water 

 being contained in the north-eastern half of the loch, the deepest 

 sounding in 80 feet having been taken about a quarter of a mile from 

 the north-eastern shore. The areas between the contour-lines and the 

 percenta ges to the total area of the loch are as follows : 



to 25 feet 77 jlpfes 44 per cent. 



25 50 69*7, 39 



Over 50 29 17 



175 , 100 



Temperature observations taken in the deepest part of the loch 

 gave 48-9 Fahr. at the surface and at 40 feet, a reading at 76 feet 

 giving 48'4. 



Loch Coir' an Fhedrna (see Plate LXXIII.). Loch Coir' an Fhearna 

 (or Corr, or a-Choire) is a fine sheet of water, well wooded along the 

 south-eastern shore, the Duke of Sutherland's lodge standing at the 

 lower (north-eastern) end. It is over 3 miles in length, and compara- 

 tively uniform in breadth, the maximum breadth being half a mile, 

 and the mean breadth over one-third of a mile. Its waters cover an 

 area of about 737 acres (considerably over 1 square mile), and it drains 

 directly an area of about 18J square miles, but since it receives the 

 outflow from Loch a' Bhealaich, its total drainage area is about 24J 

 square miles. The maximum depth of 151 feet was observed com- 

 paratively near the south-west end. The volume of water is estimated 

 at 1886 millions of cubic feet, and the mean depth at nearly 59 feet. 

 The loch was surveyed on October 15 to 17, 1902; the elevation of 

 the lake-surface on commencing the survey on the 15th was found to 



