In which decade did the following all occur in Britain - the first electric pylons (erected by South Wales Power Co), the first dogems (in Skegness) and the first pedestrian crossing (in Parliament Sqaure, London)?
1920's 1920s (decade) 1920s 1920-1929 1920–1929 Twenties The Twenties Nineteen twenties '20s 1920s literature Social issues of the 1920s Nineteen-twenties