This isn't our first time taking a look at interesting subway posters, or even English railway posters, but a new book of posters and printed matter from the history of London's Tube offers a slightly different perspective than we're used to. The book, A Logo For London, collects Tube imagery from the last 150 years and examines how the circular strike-through logo evolved. Compiled by David Lawrence, the book isn't limited to formally produced posters, but instead includes photographs, pamphlets, and anything else that informed the bar and circle logo. Check out a few images below. [images via DesignTaxi]