This Flammarion engraving, by an unknown artist, is called Empedocles Breaks through the Crystal Spheres. Its original caption read: “A missionary of the Middle Ages tells that he had found the point where the sky and the Earth touch…”
The widely circulated woodcut of a man poking his head through the firmament of a flat Earth to view the mechanics of the spheres, executed in the style of the 16th century cannot be traced to an earlier source than Camille Flammarion’s L’Atmosphère: Météorologie Populaire (Paris, 1888, p. 163) . The woodcut illustrates the statement in the text that a medieval missionary claimed that «he reached the horizon where the Earth and the heavens met», an anecdote that may be traced back to Voltaire, but not to any known medieval source. In its original form, the woodcut included a decorative border that places it in the 19th century; in later publications, some claiming that the woodcut did, in fact, date to the 16th century, the border was removed. Flammarion, according to anecdotal evidence, had commissioned the woodcut himself. In any case, no source of the image earlier than Flammarion’s book is known.