Most Important Clock in America: The David Rittenhouse Astronomical Musical Clock at Drexel University Transactions, American Philosophical Society (V

Ronald R. Hoppes is a clock conservator and retired development engineer. A member of the National Association of Watch and Clock Collectors since 1975, he served as the caretaker of the David Rittenhouse Astronomical Musical Clock on display at Drexel University's Founding Collection. His publications include The Most Important Clock in America: The David Rittenhouse Astronomical Musical Clock at Drexel University (2009).