228 BATHYMETRICAL SURVEY OF 



observed in the centre of the loch near the northern end. The area of 

 the lake-floor covered by less than 25 feet of water is about 56 acres, or 

 96 per cent, of the total area. 



Temperature Observations. Temperatures taken at 5 p.m. on July 

 28, 1902, in the deep part of the loch gave the following results : 



Surface 57'5 Fahr. 



5 feet 57'5 ,, 



7 57'5 



15 57'l 



25 ... 56'0 ,, 



Loch a' Bhaid-Luachraich (see Plate L.). Loch a' Bhaid-Luachraich 

 (or Goose Loch) lies about a mile to the east of Loch Ewe, into which 

 it drains at Aultbea by the Allt Bheithe. It is surrounded by low, 

 rounded hills, steep only towards the south-east, covered with peat or 

 morainic material. It is extremely irregular in outline, and in fact 

 may almost be looked upon as two lochs with a connecting arm. The 

 south-western part is shallow, the maximum depth observed in it 

 being 43 feet, while the north-eastern part is much deeper, having a 

 maximum depth of 143 feet; the maximum depth observed in the 

 connecting arm was 15 feet. The lower part where the stream leaves 

 the loch is thickly overgrown with reeds and rushes, and weeds are 

 abundant in the two bays at the head of the loch. It was surveyed 

 on July 29 and 30, 1902, and the elevation was determined, by levelling 

 from bench-mark, as being 309*6 feet above the sea; when levelled by 

 the officers of the Ordnance Survey on August 3, 1870, the elevation 

 was found to be 310*5 feet above sea-level. 



Loch a' Bhaid-Luachraich is over 1 J miles in length, and over a mile 

 in maximum breadth, with a mean breadth of one-third of a mile. It 

 covers an area of half a square mile, and it drains directly an area of 

 3J square miles, but since it receives the outflow from Loch Mhic' 

 Ille Riabhaich its total drainage area is nearly 4 square miles an area 

 eight times greater than that of the loch. The volume of water is 

 estimated at 486 million cubic feet, and the mean depth at 34 feet. The 

 bottom in the south-western part of the loch is rather irregular, while 

 the north-eastern part forms a simple deep basin, the maximum depth 

 of 143 feet having been observed near the centre at the widest part of 

 this portion. Section A-B is taken across this wide portion at the 

 position of the deepest sounding. The areas between the consecutive 

 contour-lines, and the percentages to the total area, are as follows: 



to 25 feet 184 acres 56'2 per cent. 



25 ,, 50 ,, 84 ,, 25-5 



50,, 75 17 ,, 5-3 



75,, 100 17 5-0 



Over 100 ,, 26 8*0 



328 . 100-0 



