THE FRESH-WATER LOCHS OF SCOTLAND. 
185 
majority of the lochs. This loch will therefore be described with some 
fulness, and those which essentially resemble it, differing mainly in size, 
will be included in the summary table giving the principal dimensions. A 
few of the other large lochs, and any of rather different structure or 
coming nearer true rock-basins, as well as Loch Obisary, on account of its 
size and depth, will be described with more detail. 
Of the thirty-nine lochs which were surveyed thirty-two are fresh- 
water, and the remaining seven are more or less salt. Some of those 
regarded as fresh may receive very exceptional tides. Lochs Duin, Strumore, 
Oban a’ Chlachain, and Leodsay are purely tidal, receiving ordinary tides, 
though their level is only moderately affected by the tides. Loch Strumore 
rises and falls about 2 feet, while the whole tide is about 18 feet. Loch 
Oban nam ITadh is of an intermediate character, the flora and fauna 
towards the lower end being purely marine, while in the upper part the 
fauna is fresh-water. Loch Caravat is so fresh that we only learned its 
tidal character from the account of the natives. 
There are no important streams in North Uist. In the western part of 
the island are some a few miles in length, and large enough to be dignified 
by names, but in the part surveyed, where most of the lochs are situated, 
they are extremely short, generally only a few yards long. The stream 
which drains Loch Scadavay and its connected chain of lochs, though of 
fair size, is of inconsiderable length. This stream, with those connecting 
all the larger tributary lochs, has a total length of only about a mile, and 
the longest portion of it, from Loch Scadavay to Loch Garbh-Abhuinn Ard, 
is less than half a mile long. 
The thirty-nine lochs surveyed belong to nineteen distinct basins. Most 
of these contain only one loch, which usually drains directly to the sea by 
a short channel, often no longer than the width of the public road. There 
are twelve of these lochs, which are the only lochs in the basins to which 
they belong, or the only locbs surveyed. They are Lochs Veiragvat, an 
Duin, nan Geireann, Hosta, Oban a’ Chlachain, Leodsay, an Tomain, Obisary, 
a’ Chladaich, Tormasad, a’ Bbarpa, and Buaille. The only important lochs 
among these are Lochs Obisary and nan Geireann. 
There are only six of the basins in which more than one loch was 
surveyed. These basins cannot be distinguished by the names of the 
streams draining them, as these are usually nameless. They are here 
distinguished by the name of the most important loch in the basin, or by 
that of the lowest, into which the others drain. 
The Scadamy Basin . — This is by far the largest of the basins, and 
includes ten lochs which were sounded, besides many smaller ones. The 
combined surface areas of all the lochs have a total measurement of nearly 
3| square miles. Loch Scadavay itself contributing nearly half of this. The 
combined drainage area extends to 14J square miles, and of this Loch 
Scadavay alone, excluding its tributary lochs, drains more than half, or over 
