Built in September 1825, Locomotion No. 1 was the first steam locomotive to be used on a public railway and was a development of George Stephenson's early designs. The wheels were built up from a number of iron castings dowelled together. The valve gear was on top of the boiler and the lower parts of both cylinders were inside the boiler, which was of the single flue type, later altered to include a return flue to aid steam production. It first ran on 27 September 1825.