The works at the Pentland Skerries were begun early in the spring of 1794. The masonry was executed by builders of Orkney; and the materials having been prepared, were partly landed on these small islands in the course of the preceding summer. The Skerries consist of two uninhabited islands, with some contiguous sunken rocks. They lie exposed to the uninterrupted force of the waves of the North Sea, and to the rapid tides and currents of the Pentland Firth , and present many convincing proofs of the wasting state of the land, by the action of the sea. The works here had been so laid out, that the towers should be in readiness for the erection of the light-rooms by the month of August; and it was expected that the lights would be ready for exhibition in the month of October. The author, to whose superintendance the completing of these light-houses was to be entrusted, as his first work for the Board, sailed from Leith on this service on the 2d July 1794; and after touching at Kinnaird Head Light-house, he landed at the Pentland Skerries on the 11th of that month, and found the masonry of the two light-house towers in such a state of forwardness, as to be then nearly ready for the light-rooms. In the month of September, these works were completed, and the lights were exhibited on the 1st day of October 1794. These lights are from oil, with reflectors, and may be described as erected on the largest of the Pentland Skerries, in Lat. 58° 43´ and Long. 3° 3´ west of London; the northmost or highest light-room being elevated 100 feet, and the lower light-room 80 feet above the medium level of the sea. The two light-rooms, relatively to each other, bear S. SW. and N. NE., distant 60 feet. The bearings, as taken from the highest light-room, by compass, are the western extremity of the Little Pentland Skerry S. by W., distant 1¼ mile; extremity of the foul ground off that Skerry SE., distant 1½ mile; Duncan’s Bay Head in Caithness; W. SW. distant 4½ miles; Noss Head SW. by W., distant 14 miles; northmost point of the Island of Stroma NW. by W., distant 6½ miles; south-western extremity of the Loather Rock on the Orkney shore N. by W., distant 3½ miles; Island of Copinsha NE. by E. ¼ E., distant 17 miles. [Sidenote: Loss of the sloop Elizabeth.] The author, having remained to complete the works at the Pentland Skerries, and to see the house lighted, sailed from Orkney on the 9th of October, in the sloop Elizabeth of Stromness. On the following day, the vessel got within three miles of Kinnaird Head Light-house, in Aberdeenshire; but the wind having suddenly shifted to the south-east, Mr Sinclair, the master, with much attention and kindness, landed the author, who continued his journey to Edinburgh by land. A very different fate, however, awaited his shipmates; for the Elizabeth having put back to Cromarty Roads, was afterwards driven to Orkney, and ultimately lost, when all on board perished.