Loch, the largest and most celebrated of the Scottish lakes, separating the counties of Dumbarton and Stirling. It lies nearly N. and S., and is about 25 miles in length. The southern portion of the lake for nearly one-third of its entire length forms a wide basin of from 3 to 7 miles in width, and contains about 30 islands, several of which are well wooded. The northern portion is very narrow, averaging little more than a mile in width. The loch is deepest in the northern part, where it attains above 100 fathoms, but gets shallower as it expands towards the S., where its general depth is under 20 fathoms. The surface of the water is 22 feet above sea level. Many streams contribute to its waters from the surrounding up-