Trans. N.Y. Acad. of Sciences, 11-27:
That Mr. J.H. Hooper, Bradley Co., Tenn., having come upon a curious stone, in some woods upon his farm, investigated. He dug. He unearthed a long wall. Upon this wall were inscribed many alphabetic characters. "872 characters have been examined, many of them duplicates, and a few imitations of animal forms, the moon, and other objects. Accidental imitations of oriental alphabets are numerous."
The part that seems significant:
That these letters had been hidden under a layer of cement.
And still, in our own heterogeneity, or unwillingness, or inability, to concentrate upon single concepts, we shall—or we sha'n't—accept that, though there may have been a Lost Colony or Lost Expedition from Somewhere, upon this earth, and extra-mundane visitors who could never get back, there have been other extra-mundane visitors, who have gone away again—altogether quite in analogy with the Franklin Expedition and Peary's flittings in the Arctic—
And a wreck that occurred to one group of them—
And the loot that was lost overboard—
The Chinese seals of Ireland.
Not the things with the big, wistful eyes that lie on ice, and that are taught to balance objects on their noses—but inscribed stamps, with which to make impressions.
Proc. Roy. Irish Acad., 1-381: