From a Washington Post story by Scott Allen headlined “Baseball’s oddest arms race featured balls thrown from the Washington Monument”:

On Dec. 6, 1884, in a ceremony that lasted 15 minutes, the aluminum capstone was placed atop the Washington Monument. A cannon fired to celebrate the completion of the structure, which had been in construction since 1848 and, standing 555 feet, was the tallest built by human hands. Later that month, P.H. McLaughlin, who oversaw the building of the stone obelisk, bet Providence Grays outfielder and Virginia native Paul Hines that he couldn’t catch a baseball tossed from one of the windows near the top.