StoryThe transit of Venus is an astronomical event in which the planet Venus place himself exactly between the Earth and the Sun. During this event, Venus appears as a little black disc over the Sun's surface. A couple of transits of Venus separated by 8 years happens every 100 years circa. The last one happened in 2004 and 2012 and the next one will take place in 2117.
In 1874 astronomers were very excited for the upcoming transit of Venus and many expeditions were sent all over the world to try and record the rare event. After the attempts to witness the 1761 and 1769 transits with telescopes failed, astronomers were confident to be able to witness and even record the transit, taking advantage of the new daguerreotype technology.
French astronomer Pierre Jules César Janssen invented a huge chronophotographic recording device which could take up to 180 pictures on a rotating daguerreotype disc at short regular adjustable intervals, called Revolver Photographique in french and photographic revolver in english. With his invention and some other telescope of his own design, he went to Nagasaki, Japan to record the event and he succeeded. The photographs could be viewed in rapid succession with Janssen's invention, giving the impression of actually seeing Venus moving in front of the Sun. The photographic revolver was then used by other astronomers as well and served as a starting point to the development of other chronophotographic recording devices, like the first movie camera.
Why It Rocks
- Depending from your point of view, it is the first movie in history.
- Even if they are not the real thing, it is amazing to watch even the test plates, since they are more than a century old.
- Without this recording and the photographic revolver, movie cameras and cinema more than likely would never existed.
- Janssen predicted that his invention could be used to film animals, with the proper modifications. Some time later, Etienne-Jules Marey modified a photographic revolver and filmed animals with it and also Janssen himself.
- Janssen appeared in two early Lumiére movies filmed in the June of 1895 that were presented in the Congres de Photographie in Lyon. He even secretly voiced himself in one of them, hiding behind the screen.
While the actual recording made in Japan is yet to be found, test recordings can be seen for free on youtube. Here is one: