Book excerpt: Between 1923 and 1947 the railway poster in Britain was in its heyday. These were the years of the so-called 'Big Four' companies: the Great Western Railway, Southern Railway, London Midland and Scottish Railway, and London and North Eastern Railway. In the competition for passengers, each of the companies developed its own distinctive style of poster advertising. This book contains over 200 of the most striking and innovative designs of the period.