Restoring a 240-Year-Old Map

The New York Times describes the process of restoring a 240-year-old map that the Brooklyn Historical Society discovered in their possession — a rare 1770 map of New York City by Bernard Ratzer, only three other copies of which were believed to exist. For a real eye-opener, look at the interactive feature giving a close-up view of the map before and after restoration. Via MapHist.