188 BATHYMETKICAL SURVEY OF 



Our gillies said that the overflow of Loch Huna enters near the west 

 end, but there was no stream when we visited it. A stream, a few yards 

 in length, comes in on the south from Loch na Moracha. A short stream 

 flows from the east end into Loch Scadavay. Rock is exposed at frequent 

 intervals all round the shore, as well as on the larger islands. 



The temperature on May 11, 1904, was 51*U Fahr. both at the surface 

 and at 15 feet. 



Loch Scadavay (see Plate LXX.). There is probably no other loch in 

 Britain which approaches Loch Scadavay in irregularity and complexity of 

 outline. It is an extraordinary labyrinth of narrow channels, bays, pro- 

 montories, and islands. Though it measures 4*- miles in length, from 

 north-west to south-east, and about 2 miles in greatest breadth, from 

 south-west to north-east, there is really no broad open water in the whole 

 loch, the broadest part being in the westernmost inlet, where there is open 

 water half a mile broad. The ratio of circumference to length will 

 illustrate how very irregular is the form though only a little over 4 

 miles in length, a rough measurement indicates a shore-line of 50 miles. 

 Very many islands stud the surface, the largest being nearly a mile in 

 length. The main road round the island now cuts Loch Scadavay into 

 two parts, which are connected by such a small channel under the road that 

 in time of flood the south loch may temporarily rise some feet higher than 

 the other, though normally they are at the same level. There is nowhere 

 any considerable depth, the deepest parts occurring as little holes, while 

 the narrows are usually shallow. A lowering of the surface by no more 

 than 6 feet would divide the loch into a dozen small lochs, and a host of 

 little ponds, while a rise of the same amount would vastly increase its 

 area by including all the higher lochs in the same basin, among them 

 such large lochs as nan Eun, Huna, a' Bhuird, and Deoravat. The deepest 

 holes are 50 feet in the south loch, and 37 feet in the north loch. 



The small superficial area is in remarkable contrast to the great shore- 

 line, both portions together measuring only 1| square miles. The mean 

 depth, also, is very low, being only about 9 feet. The narrow channels 

 leading into some of the elongate arms are often only from 1 to 2 feet in 

 depth. Some of the islands have been the sites of Dims, and these have 

 been connected with the shores by narrow causeways. The volume of 

 water is only 418 millions of cubic feet. One other loch in North Uist 

 has a greater volume, though of less superficial area, Loch Obisary having 

 about twice the volume. In the shallower parts numerous stones and 

 boulders project above the surface, rendering navigation difficult even in a 

 small rowing-boat. In several instances we were unable to complete lines 

 of soundings from this cause. The shores are in parts of peat, in other 

 parts of stones, or gravel with boulders, but rock appears in many parts. 

 The easternmost arm of the south loch, one-sixth of a mile in length, has 

 precipitous rocky cliffs on both sides. This character is continued in the 



