Ordnance Survey (OS) is the national mapping agency for Great Britain and is one of the world's largest producers of maps. Since 1 April 2015 it has operated as Ordnance Survey Ltd, a government-owned company, 100% in public ownership. The Ordnance Survey Board remain accountable to the Secretary of State for Business, Energy and Industrial Strategy. It is also a member of the Public Data Group. The agency's name indicates its original military purpose (see ordnance and surveying): mapping Scotland in the wake of the Jacobite rebellion in 1745. There was also a more general and nationwide need in light of the potential threat of invasion during the Napoleonic Wars. Ordnance Survey mapping is usually classified as either "large-scale" (in other words, more detailed) or "small-scale". The Survey's large-scale mapping comprises maps at six inches to the mile or more (1:10,560, superseded by 1:10,000 in the 1950s) and was available as sheets until the 1980s, when it was digitised. Small-scale mapping comprises maps at less than six inches to the mile, such as the popular one inch to the mile "leisure" maps and their metric successors. These are still available in traditional sheet form. Ordnance Survey maps remain in copyright for fifty years after their publication. Some of the Copyright Libraries hold complete or near-complete collections of pre-digital OS mapping.DbPedia
Commemorated on 1 plaque
Ordnance Survey 1841 - 1969 After fire destroyed its offices at the Tower of London, the Headquarters of the Ordnance Survey occupied this site in 1841. Decisions which led to the national mapping of Great Britain were made here. The original buildings were seriously damaged in the enemy air-raids of 1940; the older buildings still standing on the site, including the Director General's House, are a reminder of that age. The Ordnance Survey moved from here to offices at Maybush, Southampton, in 1969.
London Road, Southampton, United Kingdom where it sited (1841-1969)