The Roads Act 1920 required councils to'register all new vehicles and to allocate a separate number to each vehicle'and'make provision for the collection and application of the excise duties on mechanically propelled vehicles and on carriages '.
12.
Completing the list of other major imports were : petroleum and crude oil ( $ 2 . 458 billion ); airplanes and other mechanically propelled aircraft ( $ 438 . 496 million ); and wheat ( $ 421 . 413 million ).
13.
Moon made outstanding and original experimental contributions which stimulated the development of whole fields of research involving neutrons, gamma rays and novel methods of studying chemical reactions ('Mechanically propelled molecular beams : techniques and opportunities', Moon, P . B . Ralls, M . P ., Proceedings of the Royal Society A, 423, 361 371, 1989 ).
14.
Harsh legislation virtually eliminated mechanically propelled vehicles from the roads of Great Britain for 30 years, the " Locomotive Act " of 1861 imposing restrictive speed limits on " road locomotives " of 5 mph ( 8 km / h ) in towns and cities, and 10 mph ( 16 km / h ) in the country.
