What marked the start of trading before the NYSE adopted a bell in 1903?

Before the New York Stock Exchange introduced its iconic brass bell in 1903, trading sessions were opened and closed with the striking of a Chinese gong. The gong had been adopted in the 1870s as trading volume increased and a louder signal was needed on the bustling exchange floor. When the NYSE moved into its current building on Wall Street in 1903, the gong was replaced by an electrically operated brass bell powerful enough to be heard throughout the larger trading floor. The opening and closing bell tradition has continued for more than a century.