I am trying to find out a bit more about the methodology he used. Best I can find so far is page giving a bit of description about Bill Rankin mapping Chicago w

I am trying to find out a bit more about the methodology he used. Best I can find so far is page giving a bit of description about Bill Rankin mapping Chicago which Eric says inspired him to do other cities: http://www.radicalcartography.net/index.html?chicagodots http://www.radicalcartography.net/index.html?chicagodots Looks like the dots are at the block level.