built very irregularly, the sweep of the cone being different on the different sides. "It is said by Torfæus that this fort was repaired and strengthened by Erlind, who, having forcibly carried off the mother of Harold, Earl of the Orkneys, resolved to defend himself to extremity in this place against the insulted Earl. How a castle could be defended which had no opening to the outside for shooting arrows, and which was of a capacity to be pulled to pieces by the assailants, who could advance without annoyance to the bottom of the wall (unless it were battlemented upon the top), does not easily appear. But to Erlind's operations the castle of Mousa possibly owes the upper and perpendicular, or rather overhanging, part of its elevation, and also its rude staircase. In these two particulars it seems to differ from all other Picts' castles, which are ascended by an inclined plane, and generally, I believe, terminate in a truncated cone, without that strange counterpart of the perpendicular or projecting part of the upper wall. Opposite to the castle of Mousa are the ruins of another Pictish fort: indeed, they all communicate with each other through the isles. The island of Mousa is the property of a Mr. Piper, who has improved it considerably, and values his castle. I advised him to clear out the interior, as he tells us there are three or four galleries beneath those now accessible, and the difference of height between the exterior and interior warrants his assertion. "We get on board, and in time, for the wind freshens, and becomes contrary. We beat down to Sumburgh-head, through rough weather. This is the extreme south-eastern point of Zetland; and as the Atlantic and German oceans unite at this point, a frightful tide runs here, called Sumburgh-rost. The breeze, contending with the tide, flings the breakers in great style upon the high broken cliffs of Sumburgh-head. They are all one white foam, ascending to a great height. We wished to double this point, and lie by in a bay between that and the northern or north-western cape, called Fitful-head, and which seems higher than Sumburgh itself--and tacked repeatedly with this view; but a confounded islet, called _The Horse_, always baffled us, and, after three heats, fairly distanced us. So we run into a roadstead, called Quendal Bay, on the south-eastern side, and there anchor for the night. We go ashore with various purposes,--Stevenson to see the site of a proposed lighthouse on this tremendous cape--Marjoribanks to shoot rabbits--and Duff and I to look about us.