Among the books, an artifact worth millions
It's one of the most valuable and unique pieces in Penn's art collection, but chances are you've never even heard of it, let alone noticed it tucked away in a corner of Van Pelt Library's first floor. Penn's Rittenhouse Orrery is a model of the solar system, complete with accurately moving planets, and is as precise as was possible in the late 18th century, according to Bob Koch, a retired astronomy professor who has researched the orrery.




