At the Royal Institution Friday Evening Discourse (a formal lecture founded in 1826 and continuing to this day), modern physics pioneer Sir Joseph John Thomson announced a surprising discovery. Earlier that year, he had found a particle of matter a thousand times smaller than the atom. He called it a corpuscle, meaning "small body." Thomson was a professor of physics at Trinity College as well as the director of the Cavendish Laboratory at the University of Cambridge and one of the most respected scientists in Great Britain. Nevertheless, his collegues present at the lecture initially were skeptical of the news. At the time, it was an accepted scientific belief that the atom was the smallest possible particle of matter and that it was indivisible. Although it took more experimental work by Thomson and others to prove conclusively the existence of these "small bodies" - later named "electrons" - Thomson's bold statement was correct and revolutionized existing theories of atomic structure.