Clay tablet YBC 7289 with an overlay to emphasize the markings on its surface. The cuneiform inscriptions demonstrate the derivation of the square root of 2 … in sexagesimal (base-60)
via Paul Murrell
the tablet has been dated to sometime between 1800 BC and 1600 BC. Little is known of its rediscovery, except that it was acquired in 1912 AD by an agent of J. P. Morgan, who subsequently bequeathed it to Yale University.