At the request of the Philosophical Society (now the Royal Society) of Edinburgh, the Rev. Alex. Bryce of Kirknewton, about the year 1740, made a geometrical survey of the North-west coast of Scotland, including the shores of Caithness and Sutherland. This paved the way for the more extensive labours of Mr Murdoch Mackenzie, who, after finishing his excellent charts of the Orkney Islands in the year 1750, was employed by Government in a survey of the whole of the Western Highlands and Islands, from Cape Wrath in Sutherlandshire to the Mull of Kintyre. But long after the publication of these valuable charts, the navigation of the sounds and sheltered seas of this district was seldom ventured upon by the larger class of shipping employed in foreign trade. The danger of falling in prematurely with the land during the night, and the rapidity of the tides on these shores, induced the mariner to keep along the extreme points and headlands of the coast, holding his course even to the northward of Orkney and Shetland, and to the westward of the Lewis Isles by St Kilda, exposed to the heavy seas of the Atlantic Ocean. In this way, much hazard to shipping, and loss of time, were incurred; and when overtaken with gales of wind, such vessels were unable to avail themselves of the numerous bays and anchorages of the Highlands;--considerations of much importance to heavy laden ships, but especially to the smaller classes of coasting and fishing vessels. It therefore appeared, that nothing but the erection of Lighthouses, by which the mariner might identify the land under night, would render this navigation at all a safe one. [Sidenote: Proposition of a Light-house Board.] Representations had often been made by shipmasters to their owners, of the difficulties and dangers encountered in sailing along the coast of Scotland. The establishment of a Light-house Board, and the erection of Light-houses on our Northern Shores, became the topic of conversation among mercantile men; and the subject was at length brought forward at the meeting of the Convention of the Royal Boroughs of Scotland, in the year 1784, by the late Mr DEMPSTER of Dunnichen, then Provost of Forfar, and Member of Parliament, as worthy of the notice of the Legislature. [Sidenote: Passing of the Original Act, 1786.]