Douglas Dragonfly motorcycle, 1954.

UNITED KINGDOM - MAY 09: Douglas Motors Ltd of Bristol made their first motorcycle in 1906. It had a horizontally-opposed, twin-cylinder engine, the design of which was to form the basis for Douglas motorcycles for the following fifty years. The Dragonfly represents one of the last of the Douglas designs for a practical touring motorcycle, and was intended to provide economical cruising in comfort rather than high speed or rapid acceleration. It has a transversely-mounted flat twin cylinder engine with a total capacity of 348cc. A four-speed foot-change gearbox is fitted. (Photo by SSPL/Getty Images)