THE FRESH-WATER LOCHS OF SCOTLAND. 191 



are two holes 45 feet deep, one to the south-east, the other to the south- 

 west, of this heap of stones. The shore and the islands are entirely of rock, 

 except at the east end near the outflow, where there are some mounds of 

 gravel. The total length of the loch is fully If miles, and the greatest 

 breadth a little under a mile. The superficial area, two- thirds of a square 

 mile, is about equal to that of Loch Geireann Mill, and is only exceeded 

 by Lochs Scadayay and Obisary. The volume of water is 199 millions of 

 cubic feet. The mean depth is 10 feet. 



Loch Fada has a very small drainage area, 3J square miles, and 

 receives only small local burns. The outflow is by a very short stream 

 into Loch Galtarsay, whence a river half a mile in length leads into 

 Loch an Strumore. The height above sea-level on May 21, 1904, was 

 29-85 feet. 



Loch Veiragvat (see Plate LXXIL). A small loch to the north of 

 Loch Fada. It measures fully half a mile in length by a quarter of 

 a mile in greatest breadth. It is of roughly triangular form, broadest 

 towards the east end. The outline is simple, little indented. There are 

 several islands, the largest near the centre ; and many boulders appear 

 above the surface at the west end. The islets at the east end are of rock, 

 and rock also appears at a few points on the north shore, and at the west 

 end. The large island is low and grassy, and formed of stones. The 

 bottom is uneven, the greater part of it covered by less than 10 feet of 

 water. The maximum depth of 25 feet occurs in a small hole between 

 the island and the north shore. Loch Veiragvat is the highest loch 

 surveyed in North Uist. Its height on May 12, 1904, 71-85 feet above 

 the sea, is twice that of Loch a' Chonnachair, the next in elevation. The 

 temperature at the surface was 49-3 Fahr., and at 10 feet 49-0. 



Loch an Duin (see Plate LXXIII.). A tidal loch of exceedingly 

 complex form, consisting of five principal expansions, elongated from east 

 to west, with many lesser inlets and numerous islands. It is nearly a 

 mile long, and two-thirds of a mile in greatest breadth. Some of the 

 branches could not be entered. All are shallow, mostly less than 7 feet 

 deep, except the northern expansion, which is on the whole shallow, but 

 having a hole where the maximum depth is 35 feet. There are two Duns, 

 from which the loch takes its name, one in the northern branch, another, 

 very well preserved, in the southern expansion. The shores are of rock 

 covered with peat. The two lowest basins communicate separately with 

 the sea, and are filled with Fucus, Zoster a, etc. The uppermost basin 

 is very slightly salt, and fresh-water plants (Myriophyllum) grow in it. 

 The level of the loch on May 20, 1904, was 4'5 feet above the sea, and 

 there was no difference of level between 10 a.m. and 5 p.m. The tempera- 

 ture at the surface was 52'5 Fahr., at 15 feet 52-0, and at 35 feet 

 50-5. 



