THE FRESH-WATER LOCHS OF SCOTLAND. 239 



one-eighth of a mile wide, and 7 to 9 feet deep. Of the two basins which 

 lie north and south of the constriction, the northern one is mostly shallow, 

 with one little hollow of 26 feet deep to the north of the largest island. 

 The southern basin is triangular in form, and the bottom slopes most 

 steeply off the promontory on the west, close to which is the maximum 

 depth of 57 feet. The mean depth is 15 feet. 



The area of the loch is about 107 acres, and the volume of water 

 71 millions of cubic feet, nearly as great as that of Loch Vaara. The 

 drainage area, which includes Loch Vaara, measures 2| square miles. 

 Loch Clousta is fed chiefly by the overflow of Loch Vaara. At the 

 outflow into the North Voe of Clousta is a dam and sluice. On July 11, 

 1903, the surface was 7'8 feet above sea-level, nearly identical with the 

 level observed by the Ordnance Survey officers, on September 25, 1877, 

 viz. 7'9 feet. The range of temperature was less than 1 from surface 

 to bottom : 



Surface 55-8 Fahr. 



10 feet 55-8 



25 55-5 



55 55-0 



Loch of Hostigates (see Plate C.) is a very small loch in the extreme 

 north of Aithsting, measuring fully a quarter of a mile long from west 

 to east, by a fifth of a mile in greatest breadth. Relatively to its small 

 size it is fairly deep, measuring 41 feet somewhat east of the centre. The 

 mean depth is 16 feet, the surface area about 19 acres, and it contains 

 13 millions of cubic feet of water. The drainage area is only one-eighth 

 of a square mile. A small burn flows out to the north, through another 

 little loch into Uyea sound. The level could not be determined. 



On July 16, 1903, there was a range of temperature of 2'5 through- 

 out the body of water, the readings at 20 feet and at 35 feet being 

 identical : 



Surface 57-5 Fahr. 



10 feet 56-4 



20 55-0 



35 55-0 



Clings Water (see Plate C.) is a loch of moderate size in Aithsting, 

 draining through the small Loch of Setter (not surveyed) into the Voe 

 of Clousta. The surrounding moorland rises to heights of from 100 to 

 fully 150 feet above the loch. In form Clings Water is nearly square, 

 with a deep bay on the east, and a narrow arm on the west. Though 

 but a small loch, measuring only two-thirds of a mile long, by fully 

 one-third broad, it is one of the deepest lochs in Shetland, the maxi- 

 mum, 73 feet, being only 1 foot less than that of the Loch of Girlsta. 

 The mean depth is 26 J feet, second only to the Loch of Girlsta. The 

 superficial area is about 91 acres, and the contents 101 millions of cubic 

 feet. It receives only surface drainage. 



