Source: Weather Doctor’s Weather Almanac

2 p.m.: Time a mysterious darkness descended over New England on May 19, 1780. Scientists later said it was smoke from New Hampshire forest fires.

5:30 p.m.: Time darkness lifted in Cape Cod

180: Miles between Rupert, N.Y., and Barnstable, Mass., the western and eastern frontiers of the phenomenon

25: Reported speed of the cloud, in miles per hour