A slate wall is said to have been revealed during the digging of a coal mine operated by a Captain Lacey at Hammondville (Ohio, USA) in the autumn of 1869. The discoverers were James Parsons and two sons, who were present when a mass of coal at the face 100 feet (30.5 m) underground, fell away, revealing a smooth wall of slate, with several lines of strange figures carved on it in bold relief. The figures were described as alphabetic writing, with raised and well defined letters. The coal that had covered the wall is said to have borne their reverse imprint. Each sign was 19 mm (¾ inch) high and arranged in rows spaced exactly 76.2 mm (3 inches) apart. There were twenty-five symbols in the first line. Local teachers and ministers who examined the wall were unable to reach a conclusion about it. A number of academics were invited to view the wall, which inconveniently disintegrated (supposedly from exposure to the air) and the writing was lost. The discovery was reported in The Los Angeles News of 17 December 1869, using an account from The Cleveland Herald, from Wellsville (Ohio, USA).

This is another of those anecdotal discoveries that is superficially well documented but in fact full of holes. Why did no-one think to make any drawings of the symbols? Why were none of those who saw it able to give a better description to the visiting academics, especially when they had measured the symbols so carefully?