Sarah Sweet wrote in Torontoist.com, “There’s now an easier, more convenient, and more dynamic way to compare different stages in the development of Toronto: thanks to the new Toronto Historical Map viewer, you can zoom in and out of and explore maps produced between 1818 and 1924, and aerial photographs from 1947 and 2012.”
Inspired by Nathan Ng, creator of the Historical Maps of Toronto project Chris Olsen, an analyst at ESRI (a Geographical Information System technology vendor) entered the picture. Olsen proceeded to create the map viewer by georeferencing and then stitching together map plates—essentially, each map had to be tagged so that users could jump between the same location in different files—and by adding controls that allow users to slide between years. He’s also worked on historical map viewers for both Pittsburgh and Cleveland.
Read the entire story at the source on Torontoist.com .