in 1799, he filed a patent for a wind pump for compressing air to obtain motive power and the following year he patented his ‘aeolian’ engine which used compressed air to power vehicles. in his pamphlet "on the properties, power, & application of the aeolian engine, with a plan and particulars for carrying it into execution", medhurst proposed the establishment of aeolian coach services, operated by pumping stations along the route.