In lines 85-96 of his poem 'Con pura malenconía', Comendador Román warns the converso Antón de Montoro that should he ever decide to visit the town of Tábara (in present-day Zamora), he will be revealed before the whole population to be as much of a Jew as he was the day he was born. To date no one has known what to make of this cryptic statement, but I have recently come across a number of mid-fifteenth-century authors (Alfonso de Madrigal in several works, also Alonso de Espina) who mention the existence in Tábara of a curious automaton that has the property of identifying Jews. This is undoubtedly the same bizarre contraption that Román was referring to in his poem. The fame of the Tábara automaton continued to be propagated for another two hundred years (by Bartolomé de Las Casas, Rodrigo de Yepes, Juan Eusebio Nieremberg), until at last Padre Feijoo, in the eighteenth century, pointed out the outlandishness of this legend.