While the works of Island Glass were proceeding, a light-house was also erected, and lighted 10th October 1789, on the island of North Ronaldsay, in Orkney; but, as the light at this station was afterwards removed to the neighbouring island of Sanday, it will fall more properly to be noticed in the form of a Tower or Beacon, into which the building was converted, after a Light-house had been established at the Start Point of Sanday. _Pladda._ [Sidenote: Application for Pladda Light-house.] The erection of the four light-houses of Kinnaird Head, North Ronaldsay, Island Glass, and the Mull of Kintyre, completed the operations of the Northern Light-house Board, referred to in the original act of 1786; and at the time of passing that act, it was not foreseen that a greater number would be required on the coast of Scotland for a series of years. But the benefit of the lights which had already been erected, in affording much greater safety and facility to the mariner in those dangerous seas, became so apparent, that they were no sooner exhibited than applications from different quarters for new erections followed. Among these, a memorial was presented to the Commissioners by the Merchants’ House of Greenock, accompanied by a letter from the Chamber of Commerce of Glasgow, setting forth the advantages which the shipping of the Clyde would derive from the erection of a light-house upon the small island of Pladda, situated at the southern extremity of the island of Arran, and entrance of the Firth of Clyde. This memorial concluded by requesting, that the Commissioners would “take such measures as should to them seem most proper, for procuring an act of Parliament, in order to carry the erection of a light-house on the island of Pladda into execution as soon as possible.” [Sidenote: Act of 1789.] [Sidenote: Collectors appointed.]