Kircher's late work The Initiatory Sphinx (Sphinx mystagoga) (1676) shows how international his reading public had become by the end of his life; it was written for a learned French collector who had brought two mummy cases from Egypt and hoped for a translation of their hieroglyphic inscriptions. The book was printed simultaneously in Rome by the house of Vitale Mascardi and in Amsterdam by Jansson and Weyerstraet. For some readers, evidently, the interpretation of hieroglyphs in Kircher's Egyptian Oedipus remained convincing two decades after its publication.