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Leviathan Of Parsonstown
Leviathan of Parsonstown, or Rosse six-foot telescope, is a historic reflecting telescope of aperture, which was the largest telescope in the world from 1845 until the construction of the Hooker Telescope in California in 1917. The Rosse six-foot telescope was built by William Parsons, 3rd Earl of Rosse on his estate, Birr Castle, at Parsonstown (now Birr in Ireland). Design and construction Parsons improved the techniques of casting, grinding and polishing large telescope mirrors from speculum metal, and constructed steam-powered grinding machines for parabolic mirrors. His mirror of 1839 was cast in smaller pieces and then fitted together before grinding and polishing; its 1840 successor was cast in a single piece. In 1842, Parsons cast his first mirror, but it took another five casts before he had two ground and polished mirrors. Speculum mirrors tarnished rapidly; with two mirrors, one could be used in the telescope while the other was being re-polished. The telescope ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reflecting Telescope
A reflecting telescope (also called a reflector) is a telescope that uses a single or a combination of curved mirrors that reflect light and form an image. The reflecting telescope was invented in the 17th century by Isaac Newton as an alternative to the refracting telescope which, at that time, was a design that suffered from severe chromatic aberration. Although reflecting telescopes produce other types of optical aberrations, it is a design that allows for very large diameter objectives. Almost all of the major telescopes used in astronomy research are reflectors. Many variant forms are in use and some employ extra optical elements to improve image quality or place the image in a mechanically advantageous position. Since reflecting telescopes use mirrors, the design is sometimes referred to as a catoptrics, catoptric telescope. From the time of Newton to the 1800s, the mirror itself was made of metal usually speculum metal. This type included Newton's first designs and eve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lawrence Parsons, 4th Earl Of Rosse
Lawrence Parsons, 4th Earl of Rosse, KP, FRS (17 November 1840 – 29 August 1908) was a member of the Irish peerage and an amateur astronomer. His name is often given as Laurence Parsons. Biography He was born at Birr Castle, Parsonstown, King's County, Ireland, the son and heir of the astronomer William Parsons, 3rd Earl of Rosse who built the "Leviathan of Parsonstown" telescope, largest of its day, and his wife, the Countess of Rosse (née Mary Field), an amateur astronomer and pioneering photographer. Lawrence succeeded his father in 1867 and was educated first at home by tutors, like John Purser, and after at Trinity College Dublin and Oxford University. He was the brother of Charles Algernon Parsons, inventor of the steam turbine. He served as the eighteenth Chancellor of Trinity College, Dublin between 1885 and 1908. His father served as the sixteenth Chancellor. He was Lord Lieutenant of King's County and Custos Rotulorum of King's County from 1892 to his death. He w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Red Dwarf
''Red Dwarf'' is a British science fiction comedy franchise created by Rob Grant and Doug Naylor, which primarily consists of a television sitcom that aired on BBC Two between 1988 and 1999, and on Dave since 2009, gaining a cult following. The series follows low-ranking technician Dave Lister, who awakens after being in suspended animation for three million years to find that he is the last living human, and that he is alone on the mining spacecraft ''Red Dwarf''—save for a hologram his deceased bunkmate Arnold Rimmer and "Cat", a life form which evolved from Lister's pregnant cat. As of 2020, the cast includes Chris Barrie as Rimmer, Craig Charles as Lister, Danny John-Jules as Cat, Robert Llewellyn as the sanitation droid Kryten, and Norman Lovett as the ship's computer, Holly. To date, twelve series of the show have aired, (including one miniseries), in addition to a feature-length special ''The Promised Land''. Four novels were published from 1989 to 1996. Two pilot ep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
