The geographer John Green ("né" Braddock Mead) criticized Mitchell and his map soon after it appeared, emphasizing two failings with respect to Nova Scotia (an area of particular dispute with the French). Mitchell, Green noted, had used neither the astronomical observations for latitude and longitude made by Marquis Joseph Bernard de Chabert in the 1740s nor a 1715 chart of the Nova Scotia coast. In response, Mitchell released a new version of his map, now with two large blocks of text that described all of his data sources; the new version of the map also adjusted the coastline in line with Chabert's work but rejected the 1715 chart as deeply flawed. This version of the map, which Mitchell referred to as the "second edition," is commonly thought to have appeared sometime in 1757, but advertisements in the (London) "Public Advertiser" and "Gazetteer and London Daily Advertiser" on 23 April 1756 clearly indicate that this new map appeared at that time.