Observations

Toner reports from Chamonix, France on the observatory that was once on top of the world

Janssen’s telescope on display at the Alpine Museum in Chamonix

Janssen’s telescope on display at the Alpine Museum in Chamonix. Image and copyright Toner Stevenson ©, all rights reserved

French astronomer Jules Janssen (1824–1907) had the ambition to create the highest observatory in the world. An observatory stationed 4800 metres above sea level on Mont Blanc would give a clear view of the sky. Fellow scientist, Joseph Vallot, had established a meteorological, physics and glaciological observation station in Mont Blanc in 1890.

Janssen’s observatory, built in 1893, was at the highest peak and susceptible to extreme weather. The remains of the observatory, the top observation deck, and instruments are the only remains after destruction by the elements in 1910. This is now in the Museum with a number of telescopes used by Janssen and images taken of the observatory and Janssen, including one of him in his later years being carried up to the summit.

Bust of Jules Janssen on display at the Alpine Museum in Chamonix

Bust of Jules Janssen on display at the Alpine Museum in Chamonix. Image and copyright Toner Stevenson ©, all rights reserved

Janssen was a prominent French astronomer who experimented in photography of the night sky using new technologies. In 1887 he attended the conference in Paris when the Astrographic Catalogue/Carte du Ciel project was discussed with astronomers from eighteen observatories including Henry Chamberlain Russell from Sydney Observatory. An apparatus based on an idea by Janssen was used by Russell for the 1874 Transit of Venus. You can currently see this on display at Sydney Observatory and the Powerhouse Museum’s on-line collection database. The French Astronomical Society awards the Janssen prize annually and recipients have included Camille Flammarion and Albert Einstein.

At a recent Sydney City Skywatchers meeting Professor John Storey (UNSW) spoke about the Antarctic observatories and how they are built to withstand the weather and work remotely for most of the year, taking advantage of the conditions and unobstructed view of sky for both observational and radio astronomy.

Toner Stevenson, Sydney Observatory manager

4 responses to “Toner reports from Chamonix, France on the observatory that was once on top of the world

  • Oh. I should have mentioned. Chamonix valley and Mount Blanc is a really beautiful place. (If your rich enough, it is said to be the best place to ever learn French.)
    A nice set of many many terrestrial images of the region can be viewed at; http://flickriver.com/search/Chamonix+sky/

    I can see why Jules Janssen wanted to take astronomical images there!

    Merci Toner!

  • Merci pour l’article.

    To comment on some of Nick’s points here…

    H.C. Russell was certainly inspired by what was happening in Europe at the time, and he brought what he found to persuaded (more likely verbally bludgeoned) the NSW Government to adopt an important scientific programme for the glory of the Colony. Jenssen’s own enthusiasm changed some peoples views towards the international astrophotographic project. Russell embraced this wholeheartedly.

    It is interesting to read about early astronomical photography achieved by H.C. Russell. It seems that these images were popular among the general public, and whose results were actively debate with the Royal Society of N.S.W. in the 1880-1890s. One of the interesting aspects were photography from the chemical process and film sensitivities. I cannot but think that he must have had some good discussions with Jenssen astronomical photographic techniques and processes, which swung into action immediately Russell arrived back into New South Wales.

    Russell wrote in “The Sydney Observatory : History and Progress”
    (1882) http://homepage.mac.com/andjames/Page035.htm

    “Prior to Mr. Smalley’s death active preparations were going on in Europe for the then approaching transit of Venus, [when] Mr. Russell took office with a strong desire to engage in this work…..
    Parliament liberally granted £1,000 for this purpose, greater part of which was expended upon the splendid 11½-inch refractor which the Observatory now possesses, and upon the photoheliograph made after the same pattern as those used by the English observers.
    Besides these a number of minor instruments were secured, making in all twelve instruments. These were divided amongst four parties, located at Sydney, Woodford, Goulburn, and Eden; each party in addition to the telescopes for observing the ingress and egress of the planet was provided with the means of taking rapid photographs of the sun during the Transit. Of the observers only three came from the Observatory staff and the other nine were volunteers who required more or less training for the work. For this purpose regular practice upon an artificial transit and in the photographic work was kept up for some months, until all felt prepared for the work assigned to them.
    The weather proved all that could be wished, and extremely satisfactory observations of ingress and egress were secured as well as some 1,300 photographs of Venus in transit. These observations and photographs were a valuable contribution to the data in the Astronomer Royal’s report on the Solar Parallax.”

    The further advancement of astronomical photography can be seen in Russell’s article “Preparations Now Being Made in Sydney Observatory for the Photographic Chart of the Heavens.” (1891) http://homepage.mac.com/andjames/Page046.htm

    I find it interesting that the smoke generated by homes and businesses in Sydney prove to be of significant problems in the 1890s and into the 1910s. (Geoff recently talked about this with the introduction of gaslight in Sydney.

    It was noted that Government Astronomer, James Nangle :The Sydney Observatory : It’s History and Work” (1930) http://homepage.mac.com/andjames/Page036.htm (Some astronomical images by Russell also is reproduced in this article!)

    “Owing to the introduction of electrical power, there is not nearly so much. smoke in the atmosphere as formerly, but the amount of artificial light has certainly increased. Experience shows that during the early hours of the morning the skies are quite clear, and, excepting for photographic work, provide conditions sufficiently satisfactory for useful astronomical observation. In view of the circumstances, it should be continued, because it is a very useful institution, providing necessary information for civil purposes, taking a useful part in a great International Astronomical Programme, and is also of great value as a means of disseminating a knowledge of astronomy in the community”

    This too eventually changed. Now it is the electric lights that limited astronomical photography in more recent times, degenerating into difficulties with visual observation too.

    Merci pour cette histoire intéressante de loin!
    {Thanks for this interesting story from afar!)

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