“The pendulum of eternity”

“The vast cycles of change going on in the heavens seem, as it has been sublimely said, like the recurring beats of the pendulum of eternity.”

―William Augustus Norton, First Book of Natural Philosophy and Astronomy, 1860.

Providence Union Station, 1847-1896.
Providence Union Station, 1847-1896. The Foucault pendulum was suspended within one of the towers at left.

When news of Léon Foucault’s demonstration of the Earth’s rotation reached the United States in 1851 there was great interest in repeating the experiment in Providence. Two members of the Brown faculty arranged for a public demonstration in the Providence railroad depot. Alexis Caswell was a professor of natural philosophy, mathematics, and astronomy. William A. Norton was professor of civil engineering and natural philosophy. The pendulum bob weighed a little less than 40 pounds and was suspended from the end of a wire 97 feet long. The report on this experiment was published in the Proceedings of the AAAS along with an account of the Harvard demonstration in the stairwell of Bunker-Hill Monument.

The railroad station was later damaged by fire and replaced in 1898 with the Union Station that stands in downtown Providence today. Both the current Union Station and Ladd Observatory were designed by the architects Stone, Carpenter & Willson.

pendulum ball
A pendulum ball used to perform the Foucault demonstration.

The demonstration was later repeated for students on campus in Robinson Hall, which was then the Brown University Library. Prof. Winslow Upton included the experiment in his astronomy classes starting in the 1890s, as described in the Brown Daily Herald. During the 20th century there were numerous repetitions and the cable used to suspend the pendulum can still be seen attached to the ceiling.

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