1874 transit of Venus
The 1874 transit of Venus, which took place on 9 December 1874 (01:49 to 06:26 UTC),
Expeditions
French expeditions
There were six official French expeditions. One
British expeditions
There were five official British expeditions or observation sites. One
American expeditions
In the
Observations
The transit was observed from many observatories, including the
Italian astronomer Pietro Tacchini led an expedition to Muddapur, India. Other locations in India from where the transit was observed included Roorkee,[3] and Visakhapatnam.[3] The German astronomer Hugo von Seeliger directed an expedition that travelled to the Auckland Islands (subantarctic New Zealand islands).[3] German astronomers also travelled to Isfahan in Persia, and to Kerguelen.[3] The Dutch astronomer Jean Abraham Chrétien Oudemans made observations from Réunion, and observations were also made from various points in the Dutch East Indies.[3] Austrian astronomers made observations from Jassy, in what is now Romania.[3] The Russian astronomer Otto Wilhelm von Struve organised expeditions to make observations in eastern Asia, the Caucasus, Persia and Egypt. Two Mexican expeditions travelled to Yokohama in Japan.
There were also several individuals that journeyed to various locations to observe the transit, or funded private expeditions.
Not all the observers were able to make measurements, either due to adverse weather conditions, or problems with the equipment used. Many observers, particularly those on the official expeditions, used the new technique of photoheliography, intending to use the photographic plates to make precise measurements. However, the results of using this new technique were poor, and several expeditions were unable to produce publishable results or improve on existing values for the astronomical unit (AU). In addition to this, observations made of Mars were producing more accurate results for calculating the value of the AU than could be obtained during a transit of Venus.
See also
- Passage de Venus – A series of photographs taken of the transit by Pierre Janssen, listed by IMDb as the first film
Notes
- ^ The timings given here are the geocentric circumstances, as viewed from the centre of the Earth.[1] The exact timings of a transit vary by a few minutes from these timings depending on the exact location it is viewed from on the surface of the Earth. It is these variations, due to parallax, that allow measurements of the timings to be used to calculate a value for the astronomical unit.
- Transit of Venus, 2012.
References
- ^ a b "1874 December 9th Transit of Venus". Transits of Venus. HM Nautical Almanac Office. Archived from the original on 25 January 2017. Retrieved 15 June 2012.
- ^ "Transit of Venus – 19th Century". Melbourne Observatory. Archived from the original on 27 April 2012. Retrieved 15 June 2012.
- ^ a b c d e f g h i j k l m van Roode, Steven. "1874 December 9". transitofvenus.nl. Archived from the original on 25 June 2012. Retrieved 15 June 2012.
External links
- General
- 1874 Transit of Venus (The Royal Society)
- Listing of articles on the 1874 transit (transitofvenus.nl blog)
- Specific
- Mexico's international scientific expedition to observe the 1874 transit of Venus (Geo-Mexico)
- The National Academy of Sciences' Committee on the Transit of Venus, 1871 and 1881 Archived 28 January 2013 at the Wayback Machine (The US National Academies)
- 'The American transit of Venus expeditions of 1874 and 1882' (Steven J. Dick, 2004), published in Transits of Venus: New Views of the Solar System and Galaxy, Proceedings IAU Colloquium No. 196, 2004, D.W. Kurtz, ed.
- Contemporary published accounts
- Account of observations of the transit of Venus, 1874, December 8 (1881) – the official account of the five British expeditions, edited by George Biddell Airy
- Transit of Venus 1874 (1892) – account of Australian observations written by Henry Chamberlain Russell