Stewart Precision carburettor, 1911.
© Science Museum / Science & Society Picture Library
Sectioned. The carburettor is the component in an internal combustion engine which mixes air and fuel in correct proportions for combustion to occur. This is an example of the one patented by A C Stewart in 1905, 1910 and 1911. It was designed to give a constant proportion of petrol to air at all engine speeds, which it did by means of a suction lifted air valve controlling the petrol supply. It also gave a rich mixture for starting. Made by the Stewart Precision Carburettor Co.