i think it was about 1937,1938 an american archaeologist was working up on the north slope of the acropolis and he came upon a well, he dug into the well, and out came 191 inscribed potsherds, ostraka with but one name written on all of them, and that name was themistocles, who we know was a participant in a batch of ostraka in the 480s, and careful analysis of the handwriting indicated that these 191 ostraka were inscribed by 14 hands writing them.