The County Series was superceded by the National Grid Series after the Second World War.
The scale of 1:2500 is 25.344 inches to the mile. These maps are sometimes referred to as 25 inch maps.
Each map represents an area of 1.5 mile by 1 mile. Its actual size is about 1 metre by 0.66 metres.
We have a mixture of maps from the original survey of the late 1880s, and the 1905 revision.
The OS didn't give these maps a title; possibly because many of them show areas containing no major settlement or feature. Instead they used a numbering system, of the form, e.g., LXVI.8. In this example, LXVI (roman 66) identifies a block of 16 maps in a 4 x 4 grid, and the .8 indicates that this is the map on the right hand end of the second row.
We have assigned our own rough title for each map and appended it to the original OS numbering, to make the list easier to browse. In addition we have provided 'adjoining maps' information where appropriate, so users can navigate directly between adjacent sheets. As a further search option, we have extracted the names of villages, hamlets, larger estates/farms and other features of interest, to enable maps to be found by using the Browse by Place dialogue.