Category of Astronomical Heritage: tangible immovable
Lord Rosse's Leviathan of Parsonstown, Birr Castle, Irland

Description

Geographical position

Lord Rosse’s Leviathan of Parsonstown, Birr Castle, Birr, County Offaly, Leinster, Irland

Location

Latitude 53°05′48″ N, Longitude 7°55′03″ WCoordinates: 53°05′48″N 7°55′03″W , Elevation ...m above mean sea level.

IAU observatory code

Description of (scientific/cultural/natural) heritage

Fig. 1. Lord Rosse’s Large Reflecting Telescope, at Parsonstown, Birr Castle (Wikipedia)

Fig. 2. William Parsons, 3rd Earl of Rosse (1800--1867) (Steinicke)

William Parsons, 3rd Earl of Rosse (1800--1867), had his castle in Birr (formerly called Parsonstown), in County Offaly, Ireland.
He was very much interested in astronomy and very skilful telescope making, in casting, grinding and polishing his large telescope mirrors from speculum metal. He even constructed steam-powered grinding machines for parabolic mirrors.

Fig. 3. Lord Rosse’s 3 foot (91-cm) mirror of 1839/40 (focal length 7.9m) (Steinicke)

He started in 1839 with a 3-foot (91-cm) mirror of focal length 7.9-m. He first casted smaller pieces and put them together before grinding.

His succeeded in 1840 to cast the mirror in one piece.
For his 6-foot-Leviathan he made six casts in the years 1842 to 1845 and had finally two useable mirrors. He could observe with one mirror while he repolished the other one.
In 1845 also the altazimuth mounting was ready for the mirror which weighed about 3 tons.

Fig. 4. Lord Rosse’s Leviathan (1885), with Lawrence Parsons, 4th Earl of Rosse (1840--1908) (Wikipedia)

The Leviathan, a 6-foot reflecting telescope (Newtonian telescope) of 183-cm aperture (72-inch), focal length 16.5-m, was the largest telescope in the world from 1845 until the construction of the 100-inch (2.5-m) Hooker Telescope, Mount Wilson, California, in 1917. In addition, the Leviathan was mentioned in Jules Verne’s science fiction novel From the Earth to the Moon (1865).

Due to his achievements, Lord Rosse became President of the Royal Society of London in 1848

Nebular research was considerably advanced by William Parsons, third Earl of Rosse (1800--1867), who was interested in the structure of nebulae. He was a keen observer; with his metal reflecting telescopes (Newton) in Birr Castle near Parsonstown, Ireland, he had the best equipment of his time. With it, he recognised the spiral structure of M 51 and many other nebulae from 1845 onwards -- with the help of his assistants.

Fig. 5a. Spiral structure of M 51, later known as the Whirlpool Galaxy, Drawing by 3rd Earl of Rosse in 1845, based on observations using the Leviathan (Wikipedia)

Fig. 5b. M 51 in the Canes Venatici, photographed by Isaac Roberts (1829--1904) in 1889 with the 51-cm mirror - exposure of 3.5 hours

The photograph of M 51 in the Canes Venatici (Hunting Dogs) by Isaac Roberts (1829--1904) in 1889 with the 51-cm mirror shows a remarkable similarity to Lord Rosse’s visual observation.

With the largest telescope in the world at the time, he found that many of these "spiral nebulae" were resolvable into stars, but Lord Rosse still considered the "spiral nebulae" to be star clusters in our Milky Way and not extragalactic objects. In the spirals or vortices he saw centres of the formation of new stars by condensation. This seemed to confirm Laplace’s theory. Even at the turn of the century, the Chamberlin-Moulton hypothesis (Brush 1978) stated that spiral nebulae evolve into solar systems.

Mary, Countess of Rosse (1813--1885)

Fig. 5c. Mary, Countess of Rosse (1813--1885), (CC)

"Mary, the wife of William, the 3rd Earl of Rosse [1836] and mother of their four sons, three of whom can be accorded significant roles in the history of technology, is herself a fascinating figure who, at a time and in a society when ladies, particularly aristocratic ladies, were not expected or encouraged to be involved in `work’, played a very active part in the life and achievements of her extraordinary family" (Mollan 2014, p. 44-89) -- especially in the field of early photography, in a time, where a lot of chemical knowledge was necessary. She was also an amateur astronomer, blacksmith (!), and architect. She did the casting of the parts of the Leviathan; metal cast items are still around the castle grounds, e.g. the bronze gates.

Four of her eleven children survived:

Lawrence Parsons, 4th Earl of Rosse (1840--1908)
Reverend Randal Parsons (1848--1936)
Hon. Richard Clere Parsons (1851--1923) built railways in South America.
Sir Charles Algernon Parsons (1854--1931) is known for his commercial development of the Parsons steam turbine.
His wife, Lady Katharine Parsons, née Bethell (1859--1933), and their daughter Rachel Mary Parsons (1885--1956), were founders of the Women’s Engineering Society and its first and second presidents.

In 1842, Lord Rosse and Lady Mary started to experiment in daguerreotype photography (invented in 1839), and he also was in contact with William Henry Fox Talbot (1800--1877), who invented the salted paper and calotype process, introduced in 1841, which allowed to make copies of photos. Lady Rosse became a member of the Dublin Photographic Society, and in 1859 she received a silver medal for best paper negative from the Photographic Society of Ireland. In Birr Castle, there is her photographic and chemical laboratory presented, and the Birr Castle Archives keep her original remarkable photographs.

Lawrence Parsons, 4th Earl of Rosse (1840--1908)

Fig. 5d. Lawrence Parsons, 4th Earl of Rosse (1840--1908), (CC)

Lawrence Parsons, 4th Earl of Rosse (1840--1908), the son of Lord and Mary Rosse, eighteenth Chancellor of the University of Dublin between 1885 and 1908, and Fellow of the Royal Society (1867), was also interested in astronomy, mechanical engineering, and was active as amateur astronomer and added equipment to the telescopes. His research included the Moon’s radiant heat (Philosophical Transactions for 1868) with thermopiles, exhibited at the Franco-British Exhibition (1908). He applied a clock movement in 1869 to the 6-ft-reflector for micrometer measures in order to study the exact positions of nebulae, the moons of Uranus. He repaced the original altazimuth mounting of the 3-ft-reflector by a modern equatorial mounting with an electric control(1876). Especially important is, that he was interested in the new field of astrophysics.

History

Fig. 6. Six-foot telescope, three-foot telescope, and Birr castle (Painting by Henrietta Crompton, Wikipedia)

Instruments

3 foot (91-cm) mirror (1839/40), focal length 7.9m
6 foot (183-cm, 72-inch) reflecting telescope (1845), focal length 16.5m

Fig. 7. Rosse’s six-foot-telescope-mirror (Science Museum London, Wikipedia, CC BY-SA 4.0, Geni)

State of preservation

Fig. 8. Leviathan, Birr Castle (Wikipedia, Albert White)

The Large Telescope of Lord Rosse is well reconstructed in good condition - a very impressive monument of science, a highlight of astronomical instrumentation.

The original mirror is preserved in the Science Museum London since 1914.

One step forward in the direction to the Unesco application was made in 2023: Irish astronomers hope stars align for new North-South collaboration (Link) -- An event to celebrate an all-island Irish astronomy initiative will see the community honour one of their own, renowned astronomer Martin Rees.

Comparison with related/similar sites

There existed two other large reflecting telescopes (but much smaller than Lord Rosse’s telescopes), made in private observatories in Great Britain:

James Nasmyth (1808--1890), a Scottish inventor (patent: steam hammer, 1842), built a 20-inch = 50cm-Cassegrain-Newton reflecting telescope (1842), in the process inventing the Nasmyth focus, in Penshurst, Kent, South East England. He made detailed observations of the moon and photographed his plaster relief scale models of the moon surface with craters.
William Lassell (1799--1880) constructed a 24-inch = 60-cm-reflecting telescope (1844/46), in Liverpool, England, then a 48-inch = 120-cm-reflecting telescope in Malta (1863). He discovered Neptune’s moon Triton, the eighth moon of Saturn, and two moons of Uranus.

Dunsink Observatory Dublin (1785) and Armagh Observatory (1790) represent a revolution in observatory design (Gotha is not preserved) -- the earliest buildings with a dome. Together with Lord Rosse’s Birr Castle Observatory as a highlight in telescope making (reflector) and telescope mounting, the three Irish observatories move forward (since 2022) in the direction of an application for the Unesco World Heritage List.

Threats or potential threats

no threats. Birr Castle in Ireland is the present day home of the 7th Earl of Rosse.

Present use

Fig. 9. Reconstructed Leviathan, Birr Castle (Wikipedia, CC BY-SA 3.0, Tpower)

The reconstructed Leviathan in Birr Castle is used as a public observatory. The Great Telescope at Birr was opened
for public viewing in February 1997 with a new modern mirror (1999). The original historical mirror (speculum) was given in 1914 during a restoration to the Science Museum in London.

In addition, in "1996 a team from the Irish Astronomical Association came to Birr to establish a true North-South alignment line - the "Meridian" - in order to set the Meridian Arc to be reconstructed on the inside face of the east wall" (Europhysics News, 1997).

Astronomical relevance today

The historical telescope has no relevance for modern astronomy, but an important significance for history of science.

A LOFAR radio-telescope station was added in 2017.

References

Bibliography (books and published articles)

Brush, S.: A Geologist among Astronomers: The Rise and Fall of the Chamberlin-Moulton Cosmogony. In: Journal for the History of Astronomy 9 (1978), p. 1--41, 77--104.
Hoskin, Michael: The First Drawing of a Spiral Nebula. In: Journal of the History of Astronomy 13 (1982), p. 97--101.
Hoskin, Michael: Rosse, Robinson, and the Resolution of the Nebulae. In: Journal of the History of Astronomy 22 (1991), p. 331--344.
King, Henry C.: The History of the Telescope. London 1955, p. 206--217.
Mollan, Charles (ed.): William Parsons, 3rd Earl of Rosse: Astronomy and the castle in nineteenth-century Ireland. Mancheste: Manchester University Press 2014.
(https://www.jstor.org/stable/j.ctt18mvm6r)
Moore, Patrick: The Astronomy of Birr Castle. London 1971.
Moore, Patrick: The Astronomy of Birr Castle. Birr: The Tribune Printing and Publishing Group 1981.
Moore, Patrick: The Leviathan Reborn. In: Sky & Telescope 94 (1997), 5, p. 52.
Nichol, J.P.: The Architecture of the Heavens. London (9th ed..) 1851.
Obituary: MNRAS 29 (1869), 123; Proceedings of the Royal Society 16 (1867), XXXVI.
Parsons, C.: The Scientific Papers of William Parsons Third Earl of Rosse 1800--1867. London 1926.
Parsons, William (Lord Rosse): Observations on the Nebulae. In: Philosophical Transactions of the Royal Society 140 (1850), p. 499--514.
Parsons, William: On the Construction of Specula of Six-feet Aperture; and a selection from the Observations of nebulae made with them. In: Philosophical Transactions of the Royal Society 151 (1861), p. 681--745.
Parsons, William: The Construction of Specula of Six-feet Aperture and a selection from the Observations of Nebulae made with them. Part 3. In: Scientific Transactions of the Royal Dublin Society. 1861, p. 681--745 (London: Taylor & Francis 1862).
Parsons, William: Observations of Nebulae and Clusters of Stars Made With the Six-foot and Three-foot Reflectors at Birr Castle From the Year 1848 up to the Year 1878. Part 1--2. In: Scientific Transactions of the Royal Dublin Society, Vol. 2, Ser. II. Dublin: Royal Dublin Society 1880, p. 1--178.
Roberts, Isaac: A Selection of Photographs of Stars, Star-clusters and Nebulae, Volume II. London: The Universal Press 1899.
Wolfschmidt, Gudrun: Milchstraße Nebel Galaxien - Strukturen im Kosmos von Herschel bis Hubble. München: Deutsches Museum (Abhandlungen und Berichte, Neue Folge, Band 11). München: Oldenbourg-Verlag 1995.