Sir Joseph Whitworth, English mechanical engineer, c 1850s.
© Science Museum / Science & Society Picture Library
Oil painting of Sir Joseph Whitworth (1803-1887), the pioneer of precision measurement. Whitworth created a small workshop producing tools which expanded into making machine tools and engines including steam engines. Whitworth worked on small arms and later big guns and improved the quality of the steel by subjecting the moulten metal to presure during its solidification - this steel was known as 'Whitworth steel'. He became a Member of the Institution of Mechanical Engineers in 1847 when the institution was founded.