THE FRESH-WATER LOCHS OP SCOTLAND. 
241 
Burga Water (see Plate Cl.) lies about 3 miles south-east of Sandness. 
It is shaped roughly like the letter T, the stem of the letter running 
nearly north-westto south-east, the cross-stroke at right angles to it 
at the south end. There are low hills to the north-east, and higher 
hills south-westward. Burga Water is one of an extensive chain of 
lochs, forming one of the largest lake- systems in Shetland, of which, 
however, only two lochs could be surveyed. Its length is fully half a 
mile, and the greatest width, across the cross-piece of the T, is very little 
less, viz. five-twelfths of a mile. The contours of the bottom are some- 
what irregular, the 10-feet contour only nearly following the shore line. 
The 20-feet contour zigzags from side to side of the loch, unless we 
regard the various soundings on which it depends as isolated. Near the 
south end is the maximum depth of 31 feet. 
The superficial area is 78 acres, the mean depth nearly 13 feet, and the 
contents 42 millions of cubic feet. The chief sources of the loch are the 
Burn of Cattikismires from the west, and the burn from Mousavord Loch 
(not surveyed). Gibbie Laws burn flows from the east corner, Ij miles 
south-eastward into Voxterby Loch. The area draining into the loch 
slightly exceeds 2 square miles. The islands at the south end are all of 
rock ; there is rock exposed on the promontory on the west shore, and the 
channel leading to the little loch on the east is choked by rock and stones, 
so that it could not be entered. 
On the date of the survey, July 21, 1903, the surface was 115*65 feet 
above sea-level, the water being low at the time, and liable to rise 3 feet 
higher. On August 27, 1877, the Ordnance Survey officers found the 
elevation to be 116*8 feet above the sea. The range of temperature was 
2°*4 Fahr. 
Surface 
5 feet 
10 „ 
15 „ 
25 „ 
56°-8 Fahr. 
56°-l „ 
54°-8 „ 
51°-6 ,, 
51°-4 „ 
Loch of North-house (see Plate C.) is a loch of moderate size in 
Aithsting, about a mile north of Aithsting churcb. Its general form 
is peculiar. There is a main triangular body, with the apex to the 
south, from which a narrow arm runs to the north-west. The two 
portions are separated by a gravel bar, at the north end of which there is 
rock. There is also a bar of rocks near the outflow. The narrow portion 
west of the bar has a de]3th of 7 feet, and is almost flat-bottomed. In the 
main loch the maximum depth of 13 feet is at the north end, close to the 
gravel bar, and from there it gradually shoals to the south. The total 
length is five-sixths of a mile, the greatest breadth one-fifth of a mile. 
The mean depth is 6J feet, the area about 58 acres, and the volume 16 
millions of cubic feet. The drainage area measures about half a square 
R 
