Ixxxii PEEFACE. Two great mountain- chains, the Mounth and Dramalban. even extended beyond it, and left another trace of its name in the county of Clatkmannan. Beyond the Firths of Forth and Clyde the great leading physical features which influenced its terri- torial distribution were two great mountain-chains. One, termed the Mounth, extended right across the island, from sea to sea, ia one continuous and un- broken ridge. Its western termination was the great mountain of Ben Nevis, rising in one unbroken mass from a plain a little above the level of the sea to the height of 4370 feet, from thence it extended along the south side of Glen Spean and by the hill of Ben Alder between Loch Laggan and Loch Ericht ; it then forms the boundary between the counties of Perth and Inverness, till it reaches the hills at the head of the Dee, rivalling Ben Nevis in height, and it continues along the south side of the Dee, forming the great barrier between the county of Aberdeen on the one hand, and those of Forfar and Kincar- dine on the other, untU it finally sinks into the plain near the eastern sea. Its name is stiU pre- served in the latter part of the range in the pass over the hUls called the Cairn o' Mounth. The second great mountain-chain cuts it at right angles, and forms the great wind and water shear which separates the waters flowing into the western sea from those running eastwards. It was called in Latin Dorsum Britannice and Dorsi Monies Brit- annici, and its Gaelic name was Drumalhan, the Gaelic word Drum being the equivalent of the Latin