We are credibly informed that there is a Steam Engine now preparing to run against any mare, horse, or gelding that may be produced at the new October Meeting at Newmarket; the wagers at present are stated to be 10,000 1; the engine is the favourite… its greatest speed will be 20 miles in one hour, and its slowest rate will never be less than 15 miles.

Trevithick’s Portable Steam Engine

8 July 1808, The Times