The Ordnance Survey is Britain’s national mapping agency. Today its digital database, the OS Master-Map, provides geographical data to national and local governments, transport organisations, the emergency services, Army and Navy, National Health Service, architects, National Trust, insurance companies, and housing associations. On 1 April 2010, in response to the Guardian newspaper’s “Free Our Data” campaign, the Ordnance Survey made thirteen data-sets (a small proportion of its overall total) freely available to the public, from a small-scale map of Great Britain to a national gazetteer of road names. But the Ordnance Survey is most famous for its folded maps. Its Explorer series comprises 403 …
Hewitt, Rachel. "The Ordnance Survey: the Modern Mapping of Britain ". The Literary Encyclopedia. First published 27 August 2010; last revised 30 November -1.
[http://www.litencyc.com/php/stopics.php?rec=true&UID=5557, accessed 21 April 2015.]