70 BATHYMETRICAL SURVEY OF 



at the position of the deepest sounding, showed a range from surface to 

 bottom of 4 Fahr., as follows : 



Surface... 50 -0 Fahr. 



10 feet 48-0 



20 47-5 



28 46-0 



Lochan Inlhir (see Plate XXVI.). Lochan Inbhir lies about a mile to 

 the west of Lochan na Salach Uidhre, and is also irregular in outline, with 

 many islands and boulders. The length is about 1J miles, and the 

 maximum breadth one-third of a mile. The superficial area is about 145 

 acres, of which 81 per cent, is covered by less than 10 feet of water. 

 Soundings in depths of 10 feet and over were taken in four places : (1) near 

 the east end, where casts in 12 and 16 feet were made; (2) farther to the 

 north-west and close to the northern shore, where an isolated sounding in 

 10 feet was taken ; (3) in the central portion of the loch, where soundings 

 in 11, 13, and 14 feet were taken ; and (4) in the western portion of the 

 loch, where there is a large deep basin, one-third of a mile in length, 

 having a maximum depth of 50 feet, occupying a central position within 

 the basin. The volume of water is estimated at 50 million cubic feet, and 

 the mean depth at 8 feet. On the Ordnance Survey maps the elevation is 

 given as 992 feet above the sea, which makes it 30 feet lower than the 

 western division of Lochan na Salach Uidhre ; a drift-mark was observed 

 at the east end 7 feet above the level of the water. The drainage basin of 

 Lochan Inbhir is a very large one, including the drainage areas of the two 

 lochs further east, and amounting to 52 J square miles, or about 230 times 

 greater than the area of the loch. 



Temperature Observations. Serial temperatures taken in the deepest 

 part of the loch on May 20, 1903, gave the following results : 



Surface 49-0 Fahr. 



10 feet 49-0 



20 46-0 



25 45-7 



50 45-0 



The range of temperature from surface to bottom was 4, there being a 

 fall of 3 between 10 and 20 feet, while the readings at the surface and at 

 10 feet were identical. 



Loch JZilde Mbr (see Plate XXVII.). Loch Eilde Mor (or Eilt-More) 

 is the largest loch within the basin, and is situated about 6 miles south- 

 east from Ben Nevis, high mountains towering on both sides of the loch, 

 culminating in Binnein Mor (3700 feet) and Sgor na h-Eilde (3279 feet) 

 on the north-west, and Glas Bheinn (2587 feet) on the east. Unlike the 

 other lochs in the basin, Loch Eilde Mor is regular in conformation, and 

 comparatively deep, trending north-east and south-west, and about 2 miles 

 in length, with a maximum breadth of a quarter of a mile. Its waters 



