Instead, I used a day's leave today to spend what is always a fascinating and enjoyable time in the Athanaeum library, browsing through their maps for things of note. Its great to find one including the square by James Newlands (occupant of number 18a), and very useful in plotting all my recent explorations, the development of the railway, and the suspicion that a number of the printed and dated surveys ( yes I'm talking about you Mr Gage!) didn't always take the effort to go and actually check whether anything had changed on some streets. Or didn't greatly care.
The first few decades of the nineteenth century I find fascinating in this regard. Publications mentioning things existing or having been already built ( the numerous updated editions of Stranger in Liverpool are great for this) prove they must have been there, even if the latest 'contemporary and accurate' survey shows nothing there. You can't necessarily blame a lax cartographer of course. You can't survey everywhere, draw accurate plans to every building, check and publish in a day or two, so some of the survey date will always be weeks or probably months old at least, but I suspect on occasion I re-drawing of one area for the sake of one extra domestic residence wouldn't have been a high priority for everyone.