Longitude still from St Paul's. "London pub'd as the Act directs December 1st. 1803, by J Wilkes. Neele sc Strand."
Scale correct at 10 miles = 37.8mm, or 6.75 miles/inch, ie 1:430,000.
Encyclopedia Londinensis was published as a part work by John Wilkes from 1795; Essex was in issue 404, and bound into Volume VII in 1810.