188 
BATHYMETRICAL 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°*0 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 rowicg-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 
