KATRINE, LOCH, a freshwater lake of Scotland, lying almost entirely in Perthshire. The boundary between the counties of Perth and Stirling runs from Glengyle, at the head of the lake, down the centre to a point opposite Stronachlachar from which it strikes to the south-western shore towards Loch Arklet. The loch, which has a south-easterly trend, is about 8 m. long, and its greatest breadth is i m. It lies 364 ft. above the sealevel. It occupies an area of 4! square miles and has a drainage basin of 375 square miles. The average depth is 142 ft., the greatest depth being 495 ft. The average annual rainfall is 78 inches. The mean temperature at the surface is 56-4 F., and at the bottom 41 F. The scenery has been immortalized in Sir Walter Scott's Lady of the Lake. The surrounding hills are of considerable altitude, the most remarkable being the head of Ben A'an (1750 ft.) and the grassy craigs and broken contour of Ben Venue (2393 ft.). It is fed by the Gyle and numerous burns, and drained by the Achray to Loch Achray and thence by the Black Avon to Loch Vennacher. Since 1859 it has formed the chief source of the water-supply of Glasgow, the aqueduct leaving the lake about i^ m. S.E. of Strenachlachar. By powers obtained in 1885 the level of the lake was increased by 5 ft. by a system of sluices regulating the outflow of the Achray. One result of this damming up has been to submerge the Silver Strand and to curtail the dimensions of Ellen's Isle. The principal points on the shores are Glengyle, formerly a fastness of the Macgregors, the Trossachs, the Goblins' Cave on Ben Venue, and Stronachlachar (Gaelic, " the mason's nose "), from which there is a ferry to Coilachra on the opposite side. A road has been constructed from the Trossachs for nearly six miles along the northern shore. During summer steamers ply between the Trossachs and Stronachlachar and there is a daily service of coaches from the Trossachs to Callander (about 10 m.) and to Aberfoyle (9 m.), and between Stronachlachar, to Inversnaid on Loch Lomond (about 4^ m.). The road to Inversnaid runs through the Macgregors' country referred to in Scott's Rob Roy.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)