Representing the northern and southern skies, this pair of celestial charts was constructed with an azimuthal equidistant projection, that is, one showing distance from the center on a constant scale. When this projection is used for terrestrial maps, the distance from a central point to any other is easily calculated, at a cost, however, of producing extreme distortion of shape toward the edges. When used for celestial maps—where only undistortable points have any substance—forms remain recognizable all the way to the periphery. Given a set of imaginary figures—gods, beasts, and useful objects—that must conform only to the flexible norms of culture and memory, cartographers freed from mathematical constraint can fill the entire hemisphere with visually undistorted figures, even as the points they encompass maintain precise and measurable relationships with the celestial objects they represent. The resulting chart offers a lucid reminder about the way our purely fanciful and often playful imaginations can be used to organize otherwise indifferent phenomena into clear and memorable arrangements.
Produced at a time when the apparent shape of the cosmos was being reconceived as an illusory effect of our own, highly limited perspective, they offered a cogent reminder that, for all its susceptibility, the human perspective retained an indispensable measure of value. Even if it didn’t produce a direct reflection of the cosmos, it remained the lens through which the universe was commonly seen and, thus, the common point of reference for developing shared understanding. While astronomers, cartographers, and philosophers could focus their attention on aspects of experience that were invisible in their entirety, the task of navigating these realms depended—and still depends—on the reconciliation of theoretical constructs describing the world in terms of phenomena that are directly apparent from the vantage of those operating within it.