Lieutenant General Sir Henry James was a Royal Engineers officer who served as the director-general of the Ordnance Survey, the British Government mapping agency, from 1854 to 1875. Sir Henry was described by the agency itself as "perhaps Ordnance Survey's most eccentric and egotistical Director General". Sir Henry spent most of his life working for the Ordnance Survey and after becoming its head he introduced the new science of photography. He also would later claim to be the inventor of the process known as Photozincography or Zinco. Sir Henry also played a part in the resolving of the battle of the scales.

The Ordnance Survey (OS) is the national mapping agency for Great Britain. The agency's name indicates its original military purpose, which was to map Scotland in the wake of the Jacobite rising of 1745. There was also a more general and nationwide need in light of the potential threat of invasion during the Napoleonic Wars. Since 1 April 2015, the Ordnance Survey has operated as Ordnance Survey Ltd, a government-owned company, 100% in public ownership. The Ordnance Survey Board remains accountable to the Secretary of State for Science, Innovation and Technology. It was also a member of the Public Data Group.