Use link below to download KML file for use in Google Earth. This has the definitions of the sheet boundaries for all Ordnance Survey One-Inch and 1:50,000 map Series of Great Britain and Ireland and 1:25,000 Provisional Series of UK. This file has been created by Alastair Davies and updated by Steven Jules of SABRE Maps. Please address any comments, queries or error reports to firstname.lastname@example.org To download the file 'OS_Series_by_CCS-SJedits.kml' go here. To use the file, open Google Earth, then open the KML file. When opened in Google Earth, use the check boxes on the left to select/de-select the various Series offered. On the map display, click within a sheet boundary to see the sheet name and number.