Orcades or, a geographic and hydrographic survey of the Orkney and Lewis Islands, in eight maps exhibiting the rocks, shoals, soundings, quality ot the bottom, diversities of the coast, flowings, setting of the tides, and distant views of the land. also an account of the Orkney islands ; the manner of taking the survey ; the state of the tides ; and a particular description of the rocks, shoals, channels, harbours, anchoring-places, the directions, irregularities, and velocities of several streams of tide round each island ; interpreted with suitable directions for sailors by Murdoch Mackenzie [Texte imprimé]