The Flammarion engraving is a wood engraving by an unknown artist, so named because its first documented appearance is in Camille Flammarion's 1888 book L'atmosphère: météorologie populaire ("The Atmosphere: Popular Meteorology"). The engraving has often, but erroneously, been referred to as a woodcut. It has been used to represent Geocentric cosmology, including a flat earth bounded by a solid and opaque sky, or firmament, and also as a metaphorical illustration of either the scientific or the mystical quests for knowledge.
The engraving depicts a man, clothed in a long robe and carrying a staff, who kneels down and passes his head, shoulders, and right arm through a gap between the star-studded sky and the earth,
discovering a marvellous realm of circling clouds, fires and suns beyond the heavens. One of the elements of the cosmic machinery bears a strong resemblance to traditional pictorial representations
of the "wheel in the middle of a wheel" described in the visions of the Hebrew prophet Ezekiel. The caption that accompanies the engraving in Flammarion's book reads:
A missionary of the Middle Ages tells that he had found the point where the sky and the Earth touch...