books.google.co.uk - On September 16, 1896, after a period of very stormy wet weather, I saw a great migration of swallows down the Thames. It was a dark, dripping evening, and the thick osier bed on Chiswick Eyot was covered with wet leaf. Between five and six o'clock immense flights of swallows and martins suddenly appeared...http://books.google.co.uk/books/about/The_Naturalist_on_the_Thames.html?id=YftFqv4WODoC&utm_source=gb-gplus-shareThe Naturalist on the Thames
