various processes, giving elegance and beauty of a peculiar cast to the forms of the objects, and increasing the intrinsic elegance and beauty of the form by the harmonious blending of its special varieties of surface decoration, in which forms that are solidly modelled are intermingled with chased or engraved patterns and spaces filled with colour. A style of art characterised by such originality of design and excellence of execution must count for something in the history of a nation’s progress, must have its place to fill in the history of art itself, when once we have begun to realise the fact that art was not the exclusive privilege of classic antiquity. LECTURE IV. (28TH OCTOBER 1881.) THE ARCHITECTURE OF THE BROCHS. In this Lecture I have to deal with the products of a school of architecture, Celtic in its character, and absolutely peculiar to the Scottish area. On the small uninhabited island of Mousa, lying off the east coast of the mainland of Shetland, there stands a solitary stone structure, massive in size, peculiar in appearance, and still more peculiar in character. It is a tower of circular form, wide and lofty, but constructed of undressed stones laid upon each other without mortar or other binding material, so that the mass of its uncemented wall coheres simply by its own vertical pressure. Its situation is peculiar. The island is small, not over a mile in length, and less than half a mile in width, bare, flat, and rocky. The tower is placed on a small promontory on the west side of the island at the point nearest to the mainland. It stands about 20 feet back from the edge of the rocks, which slope irregularly to the tide-mark about 20 feet below. There are slight remains of an intrenchment on the sides which look landward, those facing the rocks and the sea are protected by the natural features of the ground. [Illustration: Fig. 160.—Exterior View of the Broch of Mousa, Shetland.]