Excavation of the Broch of Kettleburn, Wick, by the late Pages Alexander Henry Rhind of Sibster—Group of objects found 209–259 in it—Their deposit in the National Museum gave a new character to the collection of Scottish antiquities and a new direction to Scottish archæology—Description of the relics—Implements in stone, bone, bronze, and iron—The food of the inhabitants of the Broch—No reason for attributing to them an exceptionally low condition of culture and civilisation—Excavation of the Brochs of Kintradwell and Carn-liath, in Sutherlandshire—Group of relics found in them—The food of the inhabitants—Outbuildings or secondary constructions in connection with the Brochs—Burials found in them—Excavation of the Brochs of Yarhouse, Brounaben, Stirkoke, Bowermadden, and Dunbeath in Caithness—Description of relics found in them—Excavation of the Broch of Levenwick in Dunrossness, Shetland—Its peculiar features—The Brochs of Orkney—The Broch of Burray—The Broch of Burwick—The Broch of Okstrow—The Broch of Lingrow—The Broch of Burrian—Character of the relics found in them—Determination of the general relations of the group of remains obtained from the Brochs—They are products of an advanced state of culture, civilisation, and social organisation—The relations of the structures and their contents are Celtic, and not Scandinavian LECTURE VI. LAKE-DWELLINGS, HILL-FORTS, AND EARTH-HOUSES.