Via Colby Cosh (link semi-permanent), here’s maproom.org (no relation), from which you can download high-quality scans from old maps and atlases. Seems to be part of a larger project by map enthusiast Nick Wedd; there’s more at maproom.co.uk (also no relation).

(Neither should this site or Wedd’s sites be confused with the Map Room tavern in Chicago. And here I thought I was coming up with a reasonably unused name back in March 2003.)