How Well Would Transforming Old Maps Work?
We started with a collection old maps. Some were scanned from Warner s own collection, such as a 40-map 1890 Bromley Atlas of Boston. Others came from the high-resolution scans offered by the Library of Congress on their web site. Still others came from a variety of internet sites offering, for example, historic topographic maps of New England. Importantly, high-quality digital orthophotos from the US Geological Survey (USGS) were available to serve as an accurate base. The most detailed old maps of Boston were two from the Library of Congress 1775 Boston and Environs a map covering the entire area of Boston, and 1775 Town of Boston a map that showed every street and marked its name. But when one tried to stretch the map to fit today s Boston using a single transform, only three points would line up the three that you picked. Otherwise, streets would be way off of the current location, and the alignment only showed that while map-makers in 1777 were pretty good, they were still far fro
