Martha's Vineyard Sign Language (atlasobscura.com)
In 1979 in the town of Chilmark, on Martha’s Vineyard, Joan Poole Nash sat across from her great-grandmother Emily Howland Poole, surrounded by a team of linguists and a video camera. “Do you remember the signs for rain or snow?” In response her great-grandmother moved her hands, which were recorded on grainy, black-and-white-tape.