The enormously detailed OS County Series maps made by the Ordnance Survey are our most popular collection. Most of the British Isles has been mapped at scales of 1:2,500 (25 inches to one mile) since the mid-nineteenth century. Individual roads, buildings and field boundaries can be easily identified. They are held as paper maps, and can be ordered by Map Room staff to the RBMSS reading room in the Weston Library.
The sheet referencing system is rather complicated. From the 1860s until the 1940s, mapping at this scale was d one by county. Maps are identified by county and sheet number, and each sheet is divided into 16 sub-sheets. To find which maps cover your area of interest, see the box on the right, or contact Map Room staff for help.
one by county. Maps are identified by county and sheet number, and each sheet is divided into 16 sub-sheets. To find which maps cover your area of interest, see the box on the right, or contact Map Room staff for help.
This series covers the following:
All of the counties in the British Isles were mapped in their entirety in the nineteenth century (1st edition) and then again in the very late nineteenth or early twentieth century (2nd edition).
Most of the maps were updated once or twice more after this between 1900 and the 1940s (3rd and revised editions).
Updates were done piecemeal depending on how much change each individual map needed.
A few weren’t updated again at all until a new mapping system was introduced after the Second World War.
After this a new system was introduced, the National Grid (see box below).
6” to the mile (1:10,560) - i.e. 6 inches on the map represent one mile on the ground.
25” to the mile (1:2,500) – i.e. 25 inches on the map represent one mile on the ground.
Large scale OS maps have been produced on the National Grid system since the 1950s.
The easiest way to find out which OS large scale sheets cover your area, is to use the online index produced by the National Library of Scotland. This covers the whole of Great Britain and can be found here. Search by place name and map scale, and it will list all the published sheets that cover that place, with an index diagram to show sheet coverage.
We also have paper indexes in the Map Room which you can consult when visiting.
If you are a current member of the University of Oxford, or of another HEI that subscribes to the EDINA Digimap service, then you can use the service to view a selected range of historical and modern large scale OS maps for Great Britain, dating from the 1840s to the present day.
Digimap can also be used to download data to create your own maps.