New English Atlas
The New Map of Essex was created in 1801 as we can see from the plate, but the New English Atlas was not published until 1809; it was re-published many times up to 1842.
Scale correct at 10 miles = 92.2mm, or 2.8 miles/inch, ie 1:175,000.
The Cary maps were later sold to Cruchley who added railways progressively and used them in his Railway & Telegraphic County Atlas of England and Wales, which was published from 1857 to 1888.