Are you someone who is obsessed with Google maps, Google street view, Google satellite, Google Earth and all other such things that allow you to experience the world from the comfort of your computer?
It's also a tool that allows you create cartographical history.
There are two parts to the NYPL's new collection you need to know about.
First, there are the maps themselves: 20,000 digitized, high-resolution, historical maps. Some are as old as 1600. Many of them are of New York City and surrounding areas, but there are plenty of historical maps from around the world, too. They are available under Creative Commons, so you download them for free and do whatever you like with them.
Second, there's the "Map Warper," a web-based application that allows you to perform what the NYPL's map librarians call "rectifying." You start by selecting a historical map. (You can browse the whole collection, sort it by various categories, or use keywords to find maps you're interested in.) Then you use a split-screen interface to manipulate the old map alongside a modern digital map (looks like Google maps). The interface looks like this:
Click, drag, and pin data points until you've got a historical map of the past overlaid on a digital map of the present. You can use a slide feature to fade between the two layers on a single map.
Congratulations, you just created cartographical history. You've contributed to our collective knowledge about the world.
Watch this video for a tutorial and then start making some history!
Or just look at some cool maps.