Bartholomew's railway map of the British Isles.
John Bartholomew and Son
Edinburgh : John Bartholomew & Son, Ltd.,
[1921]
On cover: "Showing the new grouping, each group is distinguished by a separate colour"
Insets: Enlargement of South Lancashire and Yorkshire [and] Edinburgh and Glasgow District[s]; Birmingham and District; Newcastle and District; Swansea and Cardiff District; London and Suburbs.
"A 21"