Thomas Jefferson’s 1819 Rotunda Planetarium designs call for a mystifying (and dangerous) boom-and-pulley lift that would elevate an operator to adjust stars pinned to the Rotunda’s concave ceiling.
“The concave ceiling of the Rotunda,” he wrote, “is proposed to be painted sky-blue and spangled with gilt stars in their position and magnitude copied exactly.” As designed, the Rotunda’s ceiling would represent the night sky in real time—mock constellations tracing their annual progress across a wood-and-plaster firmament.
Jefferson evidently was still considering this plan as late as July 1824, when he wrote to John Vaughan, librarian of the American Philosophical Society in Philadelphia, asking if there were “such a thing as a Fresco painter in Phila[delphia].?” “We shall need one to paint the cieling of our Rotunda,” Jefferson added. In response, Vaughan informed the no doubt disappointed Jefferson that “there is no professed Painter of that Branch” in Philadelphia and that he would have to look elsewhere, perhaps even employing an artist from abroad.
Here, the documentary trail runs cold. Presumably, faced with ballooning costs and persistent delays in the Rotunda’s construction, Jefferson abandoned the idea. In consequence the Rotunda Planetarium was never realized and the Rotunda Library opened two years later capped by an unadorned dome.
New evidence suggests that Jefferson’s designs were not entirely new, however, and that they might have owed something to Voltaire’s 1768 novella, La Princesse du Babylon. An avid reader of the French philosophe’s works, Jefferson likely had Voltaire’s fanciful account of a planetarium in mind when designing his own: among the gardens of Voltaire’s fictional Babylon was “a circular room, three hundred feet in diameter, with a vaulted roof painted blue and seeded with golden stars representing all the constellations and planets, each in its true position.” What’s more, this spangled vault “rotated, so that the sky was moved by machines as invisible as those that move the cosmos.”
The Rotunda Planetarium exhibition will place Jefferson’s designs in the long history of humankind’s attempt to bring the night sky indoors; and while it aims for a similar effect, our Rotunda Planetarium trades Jefferson’s fresco painter and boom (“a white oak sapling of proper strength [!]” moved on “a compound joint admitting motion in any direction”) for an array of carefully calibrated digital projectors, keeping Rotunda Planetarium visitors and University staff safely earthbound!
Over the coming months, we will post updates, anecdotes, and discoveries here narrating the development and installation of the Rotunda Planetarium. Stay tuned!