Early chronophotography of the 1874 Venus transit, captured by Jules Janssen in Japan using his "photographic revolver" for scientific research.Early chronophotography of the 1874 Venus transit, captured by Jules Janssen in Japan using his "photographic revolver" for scientific research.Early chronophotography of the 1874 Venus transit, captured by Jules Janssen in Japan using his "photographic revolver" for scientific research.