"_9th August, 1814._--Waked at seven, and find the vessel has left Lerwick harbor, and is on the point of entering the sound which divides the small island of Mousa (or Queen's Island) from Coningsburgh, a very wild part of the main island so called. Went ashore, and see the very ancient castle of Mousa, which stands close on the seashore. It is a Pictish fortress, the most entire probably in the world. In form it resembles a dice-box, for the truncated cone is continued only to a certain height, after which it begins to rise perpendicularly, or rather with a tendency to expand outwards. The building is round, and has been surrounded with an outer-wall, of which hardly the slightest vestiges now remain. It is composed of a layer of stones, without cement; they are not of large size, but rather small and thin. To give a vulgar comparison, it resembles an old ruinous pigeon-house. Mr. Stevenson took the dimensions of this curious fort, which are as follows: Outside diameter at the base is fifty-two feet; at the top thirty-eight feet. The diameter of the interior at the base is nineteen feet six inches; at the top twenty-one feet; the curve in the inside being the reverse of the outside, or nearly so. The thickness of the walls at the base seventeen feet; at the top eight feet six inches. The height outside forty-two feet; the inside thirty-four feet. The door or entrance faces the sea, and the interior is partly filled with rubbish. When you enter you see, in the inner wall, a succession of small openings like windows, directly one above another, with broad flat stones, serving for lintels; these are about nine inches thick. The whole resembles a ladder. There were four of these perpendicular rows of windows or apertures, the situation of which corresponds with the cardinal points of the compass. You enter the galleries contained in the thickness of the wall by two of these apertures, which have been broken down. These interior spaces are of two descriptions: one consists of a winding ascent, not quite an inclined plane, yet not by any means a regular stair; but the edges of the stones, being suffered to project irregularly, serve for rude steps--or a kind of assistance. Through this narrow staircase, which winds round the building, you creep up to the top of the castle, which is partly ruinous. But besides the staircase, there branch off at irregular intervals horizontal galleries, which go round the whole building, and receive air from the holes I formerly mentioned. These apertures vary in size, diminishing as they run, from about thirty inches in width by eighteen in height, till they are only about a foot square. The lower galleries are full man height, but narrow. They diminish both in height and width as they ascend, and as the thickness of the wall in which they are enclosed diminishes. The uppermost gallery is so narrow and low, that it was with great difficulty I crept through it. The walls are