■ In 1840, Britain’s first adhesive postage stamp, the Penny Black, officially went into circulation five days after its introduction. ■ In 1889, the Paris Exposition formally opened, featuring the just-completed Eiffel Tower. ■ In 1910, Britain’s Edwardian era ended with the death of King Edward VII; he was succeeded by George V. ■ In 1915, Babe Ruth hit his first major-league home run as a player for the Boston Red Sox.