A cannon-fire relay communicates and celebrates the opening of the Erie Canal.
"In 1825, the first boat bound for New York City left Lake Erie and entered the newly completed Erie Canal. Observers at the point where the canal met the lake saw the boat and fired a cannon. Some miles to the east, people heard the shot and fired a cannon there; when sound of that shot reached a cannon farther east, someone fired that one; and so on, in a sequence of hundreds of cannon placed at intervals along the canal route, down the Mohawk River, and down the Hudson River all the way to New York City. At the final shot, an hour and twenty minutes after the first, the sequence was reversed, from the city all the way back to the lake. The Echo Cannonade (as people called it) announced the opening of the canal and began a big celebration in the city."