RE: telescopes

From: Glenn Morton (
Date: Thu Jan 24 2002 - 08:43:05 EST

  • Next message: Glenn Morton: "RE: Distance of spiral nebulae"

    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.

    >-----Original Message-----
    >From: []On
    >Behalf Of Jonathan Clarke
    >Sent: Wednesday, January 23, 2002 1:48 PM
    >Cc: Asa@Calvin. Edu
    >Subject: Re: telescopes
    >As I recall the Birr Castle Leviathan suffered from the Irish
    >weather: seeing
    >was poor, the reflective coatings on the mirror corroded, and the
    >the weather
    >often prevented observations. Rosse should have come to
    >Australia.... Despite
    >its size, it was last used in 1878 was dismantled in 1904.
    >Recently it has
    >been restored for amateur astronomers.
    >Incidently Rosse's grandfather was a member of the notorious
    >Hellfire Club and
    >his son was the inventor of the steam turbine. An interesting family.
    >Glenn Morton wrote:
    >> For those who continue to question the observational data available to
    >> Whewell, they should consider that the Lord Rosse telescope of which he
    >> spoke was built in 1844 and Lord Rosse used it to view the nebula as
    >> outlined in a previous post. One source on this telescope said that this
    >> scope, whose data Whewell rejected, was the largest telescope in
    >> until well into the 20th century:
    >> "The tube was 57 feet long and up to eight feet in diameter. It was
    >> suspended between mighty masonry walls 70 feet long, 56 feet high, and 24
    >> feet apart. The whole instrument was reported to have cost
    >20,000, a truly
    >> astronomical sum for an amazing astronomical instrument.
    >> The telescope was a considerable success, seeing further into space than
    >> anything which had gone before, and it remained the largest
    >telescope in the
    >> world from 1845 until well into this century. It attracted as visitors to
    >> Birr the most eminent scientists and others who wished to experience the
    >> wonders seen through it. Its most famous discovery was the
    >spiral shape of
    >> some nebulae - now known to be neighbouring galaxies.
    >> Within the last few months, the telescope, nicknamed The Leviathan of
    >> Parsonstown - the Leviathan being a legendary monster, and
    >Parsonstown being
    >> an old name for Birr - has been restored, and is now a
    >magnificent sight at
    >> Birr Castle Demesne. It still awaits a new mirror, but this is
    >on the way.
    >> One of the two original six foot mirrors - the second is lost - is in the
    >> Science Museum in London - but attempts to get it back have proved
    >> unsuccessful. Maybe we'll get it back one day.
    >> William Parsons, Third Earl of Rosse, who received many honours
    >in his day,
    >> including Presidency of the Royal Society, died from cancer at No.1 Eaton
    >> Square in Monkstown, Co. Dublin, on October 31, 1867. "
    >> It was the 100-inch telescope which replaced Lord Rosse's as the
    >largest in
    >> 1918! Thus the majority of the data available to the debaters in the 1920
    >> about where the nebula lay, consisted of data from telescopes
    >smaller than
    >> Lord Rosse's. This means that Whewell had at his disposal the
    >knowledge from
    >> a telescope which was bigger than most telescopes in use today!
    >The Hubble
    >> has an aperture only slightly larger than Rosse's at 94 inches or 8 feet.
    >> So please, if we are to criticise my criticism of Whewell's astronomic
    >> knowledge, understand what he had available to him.

    This archive was generated by hypermail 2b29 : Thu Jan 24 2002 - 00:45:49 EST