Re: telescopes

From: Jonathan Clarke (
Date: Thu Jan 24 2002 - 16:42:11 EST

  • Next message: Jonathan Clarke: "Re: Distance of spiral nebulae"

    Hi Glenn

    My only point was that although the Leviathan of Birr Castle was a technical
    triumph and the largest telescope until the Mt Wilson 100", it was not regarded
    as a great operational success as it could have been because of its poor
    location. Had it been better sited (and perhaps part of a public observatory,
    rather than a private one) it could still be in use as a research instrument.

    You seem to have made your mind up on Whewell, one of the great geologists of
    the 19th century. Be that as it may he did not have the finest telescope in the
    world available to him. It was a private telescope earned owned by the Earl of
    Rosse, I find no mention that anyone else, apart from his assistants, ever used
    it. The observations made by the Earl of Rosse were before the use of
    photography, so all that Whewell (and every else) could judge him by was the
    quality of the drawings. Remember the canals on Mars? They come from the same
    era and techniques.

    So what we have is Whewell rejecting observations made with the naked eye,
    recorded by hand, made by somebody else. Even after the advent of photographic
    techniques one could still express doubt that the star like points in the spiral
    nebulae were in fact stars. The nucleus of a comet can appear star like, so
    suggesting they were agglomerations of comments was not unreasonable. it also
    fits in with the idea that the spiral nebulae were protostellar nebular. The
    fact that Shapley in 1920 could still express doubt that the spiral nebulae were
    made of stars, rather than other forms of matter, suggests that scepticism in
    1850's was entirely reasonable.

    What we need to establish is 1) how many other people in the early 1850's also
    claimed to have resolved point light sources in spiral nebulae, 2) how many of
    these thought they were stars and how many other forms of matter, such as
    comets, and 3) what were Whewell's reasons for rejecting the star
    interpretation, was it because it was an unlikely interpretation based on what
    was known then, or because it was theologically incompatible with his ideas?



    Glenn Morton wrote:

    > Hi Jonathan, Yes the seeing is poor for telescopes in the British Isles. It
    > is rarely clear here so observing time would be very limited but it was also
    > for Herschel's scope.(but when it is clear, it is spectacular!) As to
    > corrosion, no doubt, but Whewell had the information from the first 8 years
    > of the scope and surely no one is going to charge that they put corroded
    > coatings on the objective from the start. But the fact remains that Whewell
    > rejected observations which clearly contradicted what he was saying. And the
    > fact remains, that he had the best telescope that the world had from 1844
    > until 1918 available to him.

    This archive was generated by hypermail 2b29 : Thu Jan 24 2002 - 17:19:30 EST