been inhabited in the beginning of the twelfth century by the chief Thorbjörn, whom the Earls Magnus and Hakon attacked and killed in “Borgarfjörðr.” The ground plan of the ruin (after Hibbert) shows how the chambers were disposed in the thick stone wall. [Illustration: [++] Tower: Burra Firth] Another ancient Celtic tower, which tradition decidedly states to have been occupied by Norwegians, and which, on that account, has a particular interest for a Scandinavian, lies on the little island of Mousa (the ancient “Mösey”), close to the sound that separates the island from the south-eastern coast of Mainland. The tower is, fortunately, the best preserved one of the kind in the British Islands. It rises to the height of between forty and fifty feet, like an immense and perfectly round stone pillar, but bulging out towards the middle. Its appearance from without is quite plain, and no other opening can be perceived in the wall than the entrance-door, which even originally was so low that it was necessary to creep through it. To attack the tower, even when the door stood open, was not easy, and the bulging of the wall in the middle rendered the scaling of it almost impossible. The entire tower is about fifty feet in diameter, and consists of two concentric stone walls, the innermost of which encloses an open space of about twenty feet wide. The two concentric walls are each five feet thick, and stand at a distance of five feet from each other. The small space between them formed the habitable part of the tower. From the open yard we ascend a stone staircase, and, before we reach the top, seven divisions or stories are passed, separated by large flag-stones, which form a ceiling for one story and a floor for the next. In the different compartments, which quite encircle the tower, are small square openings, or air holes, one above the other, and looking out into the inner yard. The annexed drawings and sections (taken from Hibbert’s description of Shetland), which represent the tower in its evidently original state, will serve to explain still more clearly the nature of this simple, yet remarkable, building. [Illustration: [++] Tower: Mousa] [Illustration: [++] Tower: Mousa - Interior]