Bacon's Atlas of London & Suburbs
This has a plate number 39 in the toop right corner, which shows it to be the London Atlas rather than any of the others.
Scale displayed at 10 miles = 63mm, or 4.0 miles/inch; actual is 3.9 miles/inch, or 1:250,000.
The railway lines include the light rail to Tollesbury Pier (opened 1907), but not the Thaxted branch (opened 1913).