Having trained as a civil engineer and surveyor, the ornithologist William Eagle Clarke (1853–1938) established himself in his field by preparing reports on bird migration for the British Association. Focusing on the species passing through the British Isles, Clarke spent many months in various lighthouses and on remote islands. He brought all his research together in this two-volume work, first published in 1912 and illustrated with maps and weather charts. In Volume 2, Clarke describes key examples of his investigations. Photographs of the sites he visited accompany the text. The locations range from the Flannan Isles, in the Outer Hebrides, to the island of Ushant, off the coast of Brittany. Clarke's expedition to the latter location ended abruptly when he and his colleague were mistaken for spies and forced to leave. Extensive coverage is also given to Fair Isle, between Shetland and Orkney.