[Sidenote: Description of Corsewall Light.] “Corsewall light-house is situate in the county of Wigton, in North Lat. 55° 1´, and West Long. 5° 5´. It bears by compass, from Millour Point, on the western side of the channel leading into Loch Ryan, W. by S., distant about two miles; from Turnberry Point, SW. 21 miles; from the Craig of Ailsa SS. W. 15 miles; from the Mull of Kintyre S. E. S. 31 miles; from the Hulin or Maiden rocks on the coast of Antrim, E. by S. 20 miles; from Copeland Light-house, near the entrance of Belfast loch, NE. ½ E. 22 miles, and from Laggan point in Galloway, NE., distant 3½ miles. To distinguish this light, which is from oil, with a reflecting and revolving apparatus, from the other lights upon the coast, it is known to mariners as a _Revolving light with colour_, and exhibits from the same light-room a light of the natural appearance, alternating with a light tinged with a red colour. These lights, respectively, attain their greatest strength, or most luminous effect, at the end of every two minutes. But, in the course of each periodic revolution of the reflector-frame, the lights become alternately fainter and more obscure, and, to a distant observer, are totally eclipsed for a short period. The light-room at Corsewall is glazed all round, but the light is hid from the mariner by the high land near Laggan Point, towards the south, and by Turnberry Point towards the north. This light is elevated 112 feet above the medium level of the sea, and its most luminous side may be seen like a star of the first magnitude, at the distance of five or six leagues, but the side tinged red being more obscured by the colouring shades, is not seen at so great a distance.” _Isle of Man._ [Sidenote: Rate of Light-house duties for the Isle of Man.] The subject of the erection of the light-houses on the Isle of Man, having again been agitated by the merchants of Liverpool, the rates of duty which would probably be demanded for the erection of a light-house upon the Calf of Man, was procured from one of the agents of the Trinity-House of London upon that coast. This schedule of duties appearing to be high, a correspondence took place between Mr William Laird of Liverpool, and Mr Quintin Leitch of Greenock, respecting the rate of Scotch light-house duties, which was ultimately brought under the notice of the Commissioners of the Northern Light-Houses, by Sir William Rae, Bart. [Sidenote: ~1802.~] [Sidenote: Author’s Report on this subject.]