Awesome. But that's a low res scan. You can see a very high res scan here: http://www.davidrumsey.com/luna/servlet/detail/RUMSEY~8~1~248974~5516374:Isochronic-

Awesome. But that's a low res scan. You can see a very high res scan here: http://www.davidrumsey.com/luna/servlet/detail/RUMSEY~8~1~248974~5516374:Isochronic-Distance-Chart,-1904--Av http://www.davidrumsey.com/luna/servlet/detail/RUMSEY~8~1~24... Also, a scan of Galton's original isochronic map from 1881 is on Wikipedia; see: https://en.wikipedia.org/wiki/Isochrone_map https://en.wikipedia.org/wiki/Isochrone_map