1901 - 1906
In 1901 Harry Heatly and Frank Gresham took over the Bassingbourn Iron Works, which dated from the 1860s, and built a car of their own design, powered by a 10-hp horizontal 2-cylinder engine, with 2-speed epicyclic transmission and chain drive. The chassis had a transverse front spring, and full elliptic rear springs and further suspension was provided for the body which had semi-elliptic springs between it and the chassis.
All the parts for the Rational were made in the small Bassingbourn works, which employed 20 men. The first two bodies were also made there, but most came from Wilson of Royston, although a 4-door limousine of 1905 was made by Sanders of Hitchin. In 1904 Heatly and Gresham leased a factory at the newly built Letchworth Garden City, being the first business to set up there. Though they never made cars there, they flourished at Letchworth for many years making air compressors and other components. Their last work at Bassingbourn was to make 13 taxicabs with underfloor engines and central driving position for the London Motor Cab Co. Like some of the cars they had solid tyres although these were placed by pneumatics in 1906.
Source: Nick Georgano / The Beaulieu Encyclopaedia of the Automobile