In another response to physicsdude's wonderings about the 16th edition, the pedia of the wiki is informative in this instance
https://en.wikipedia...on's_Star_Atlas
as is also this
http://www.ianridpat.../nortonpage.htm
Ridpath of the Ian's not Nicholson of the Iain's.
Notice Norton's deep involvement with his work for a long time, and his charts sticking to the latest available data, and remember you had to get copies of those sorts of catalogues in those days, which would have been short runs and mostly in specialist libraries and no doubt quite expensive. I doubt Norton made much money from this dedicated task he'd set himself.
I remember the 17th edition being kind of a hybrid version of the classical and new stuff, but essentially Norton's was destroyed in the 18th edition by the look of things, and even more totally divorced in the final version, as in totally re-written, so in many ways it is good it ended there as that wasn't really a Norton's, possibly even the 18th Edition wasn't, whereas the 17th just had new bits which had also happened with earlier editions, it seems.
I'm sure if Pasachoff hadn't been a dedicated direct student of Menzel the Petersen Field guide updates would also have been fully ruined instead of updated. Although I did always prefer the negative plate images in the original, it may surprise some to know that white dots drawn on black pages under a dim red light (say a filtered Halpha LED) is far better than black dots on white in terms of keep dark adaptation whilst still being quite readable.
They were it for me, if I needed anything extra I used Guide 2.0 onwards, and as I think I've said before that meant the Uranometria Volume I and Field Guide I'd saved up for ended up being expensive white elephants barely used at all.
Of course THE handbook was Burnham's, maybe one or two others still around on the shelf.
In fact Norton's has always been more of a reference tome to me as its beauty was that it was an ASTRONOMY book, even the limited bits of astrophysics in it are far more astronomy than physics (eg HR diagrams and spectral types). Moon map was rubbish of course, but in my personal view all non-photographic Moon maps are, but Mars map was okay for my scope. It's probably because of Norton's that I still think of 1 AU as 93,000,000 miles first then have to remember 150,000,000 km afterwards and much similar. Haven't read it in full in years but must've read it multiple times when first bought. I notice too that it has little pencil dots against the objects I'd observed up to probably the late 90s, which includes more double stars than I remember ever looking at.