Dunsink Observatory
Encyclopedia
The Dunsink Observatory is an astronomical
observatory
established in 1785 in the townland
of Dunsink
near the city of Dublin, Ireland
.
Its most famous director was William Rowan Hamilton
, who, amongst other things, discovered quaternions, the first non-commutative algebra
, while strolling from the observatory into the centre of the city with some friends and his wife. He is also renowned for his Hamiltonian formulation of dynamics. In the late 20th century, the city encroached ever more on the observatory, which compromised the seeing
. The telescope
, then no longer state of the art, was used mainly for public 'open nights'.
of Dunsink
, 84m above sea level. The South Telescope or 12 inch Grubb, is a refracting (uses lens) telescope built by Grubb Parsons, completed in 1868. The achromatic lens, actually about 11.75 or 11.8 inches, was donated by Sir James South
in 1862, who had purchased the lens from Cauchoix of Paris 30 years earlier. He had intended it for a large but troubled equatorial that came to fruition in the 1830s, but was dismantled around 1838. The Observatory of the Late Sir James South, Journal: Astronomical register, vol. 8, pp.196-199] (See also Great refractor
s)
The entry for the observatory in Thom's Directory (1850) gives the following account of the observatory,
Astronomy
Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...
observatory
Observatory
An observatory is a location used for observing terrestrial or celestial events. Astronomy, climatology/meteorology, geology, oceanography and volcanology are examples of disciplines for which observatories have been constructed...
established in 1785 in the townland
Townland
A townland or bally is a small geographical division of land used in Ireland. The townland system is of Gaelic origin—most townlands are believed to pre-date the Norman invasion and most have names derived from the Irish language...
of Dunsink
Dunsink
Dunsink is a townland near Finglas, north Dublin, Ireland.Dunsink has an important observatory, where William Rowan Hamilton and Hermann Brück were both directors. It is the oldest scientific institution in Ireland...
near the city of Dublin, Ireland
Ireland
Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...
.
Its most famous director was William Rowan Hamilton
William Rowan Hamilton
Sir William Rowan Hamilton was an Irish physicist, astronomer, and mathematician, who made important contributions to classical mechanics, optics, and algebra. His studies of mechanical and optical systems led him to discover new mathematical concepts and techniques...
, who, amongst other things, discovered quaternions, the first non-commutative algebra
Algebra
Algebra is the branch of mathematics concerning the study of the rules of operations and relations, and the constructions and concepts arising from them, including terms, polynomials, equations and algebraic structures...
, while strolling from the observatory into the centre of the city with some friends and his wife. He is also renowned for his Hamiltonian formulation of dynamics. In the late 20th century, the city encroached ever more on the observatory, which compromised the seeing
Astronomical seeing
Astronomical seeing refers to the blurring and twinkling of astronomical objects such as stars caused by turbulent mixing in the Earth's atmosphere varying the optical refractive index...
. The telescope
Telescope
A telescope is an instrument that aids in the observation of remote objects by collecting electromagnetic radiation . The first known practical telescopes were invented in the Netherlands at the beginning of the 1600s , using glass lenses...
, then no longer state of the art, was used mainly for public 'open nights'.
History
The site was established on the south slope of a low hill in the townlandTownland
A townland or bally is a small geographical division of land used in Ireland. The townland system is of Gaelic origin—most townlands are believed to pre-date the Norman invasion and most have names derived from the Irish language...
of Dunsink
Dunsink
Dunsink is a townland near Finglas, north Dublin, Ireland.Dunsink has an important observatory, where William Rowan Hamilton and Hermann Brück were both directors. It is the oldest scientific institution in Ireland...
, 84m above sea level. The South Telescope or 12 inch Grubb, is a refracting (uses lens) telescope built by Grubb Parsons, completed in 1868. The achromatic lens, actually about 11.75 or 11.8 inches, was donated by Sir James South
James South
Sir James South was a British astronomer.He helped found the Astronomical Society of London, and it was under his name as president of the society from 1831 to 1832 that a petition was successfully submitted to obtain a royal charter in 1831, whereupon it became the Royal Astronomical...
in 1862, who had purchased the lens from Cauchoix of Paris 30 years earlier. He had intended it for a large but troubled equatorial that came to fruition in the 1830s, but was dismantled around 1838. The Observatory of the Late Sir James South, Journal: Astronomical register, vol. 8, pp.196-199] (See also Great refractor
Great refractor
Great refractor refers to a large telescope with a lens, usually the largest refractor at an observatory with an equatorial mount. The preeminence and success of this style in observational astronomy was an era in telescope use in the 19th and early 20th century. Great refractors were large...
s)
The entry for the observatory in Thom's Directory (1850) gives the following account of the observatory,