Bartholomew's Revised Half Inch to Mile Series - Essex - England & Wales Sheet 26 (C1)
The same map appears in these two different covers. In the blue cover the map is paper, Price 2/6 Net. Although the cover is labelled Sheet 16 (meaning from the Great Birtain series), the map itself still has the old has sheet codes 26 and C1, ie the old England & Wales series and the intermediary code whilst planning the transfer from England & Wales to Great Britain series.
In the brown cover the map is paper mounted on cloth (but not dissected), Price 4/- Net. The cover has the old series sheet codes "C.1" and "Eng 26".
Scale of 10 miles = 128.5mm, or 2.0 miles/inch, ie 1:126,720.
More details on Bartholomew's maps are on the Publisher's page.
Still has symbol for Aerodrome, and a few are marked; new symbol for National Trust properties. Printing code B39, ie the second half of 1939.
John Bartholomew & Sons Ltd. By Appointment to the late King George V.