Astronomical Heritage Finder


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Short Description (ICOMOS-IAU Case Study format):
Sydney Observatory, New South Wales, Australia


Geographical position 
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Observatory Hill, Sydney 2000, Australia


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Latitude 33° 51′ 35″ S, longitude 151° 12′ 17″ E (trig marker on top of tower). Elevation 44m above mean sea level.


General description 
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Sydney Observatory began operations in 1858 on a small hill located near Sydney Harbour. It is best known for its involvement in the observations of the 1874 transit of Venus and for its participation in the International Astrographic Catalogue project. The Observatory remained a working observatory until 1982 when it came under the auspices of the Powerhouse Museum and became a museum of astronomy and a public observatory.


Brief inventory 
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Fig. 1: Sydney Observatory today. Photograph Geoff Wyatt © Powerhouse Museum


Fig. 2: Sydney Observatory in 1858. Drawing from William Scott’s Astronomical Observations made at the Sydney Observatory
in the Year 1859
(Powerhouse Museum Research Library)


The buildings on the site include the Observatory building with two copper telescope domes, the south one of which houses a 29-cm refractor by Hugo Schroeder dating from 1874, while the northern dome has a modern telescope for public observing. There is a transit room with two slits, under one of which is a 15-cm Grubb transit circle installed in 1877. A tower near the main axis of the building contains the original mechanism from Maudslay, Sons & Field of London for the working time ball that sits on its roof. As was the custom in the 19th century, the Government Astronomer and his family lived in the building, the eastern half of which being the residence.

Fig. 3: The time ball being raised. Photograph © Powerhouse Museum


Fig. 4: Part of the time ball mechanism. Photograph Nick Lomb © Powerhouse Museum


Significant instruments

Three significant instruments are in situ:

  • a 29-cm refractor by Hugo Schroeder, which was purchased for the 1874 transit of Venus and recently repainted on the basis of paint scrapes;
  • the 15-cm Grubb transit circle installed in 1877 that was used to determine the geographical coordinates of Sydney, provide time and to obtain positions of comparison stars for the Sydney Zone of the International Astrographic Catalogue; and
  • the time ball and its mechanism from Maudslay, Sons & Field of London dating from 1855, making Sydney Observatory one of only a very few places in the world with a working time ball operated by its original mechanism.

Other significant objects on display at Sydney Observatory include a JH Dallmeyer photoheliograph also purchased for the 1874 transit of Venus and which is complete with a Janssen style photographic revolver – the only British-made one known to be still in existence, and a Frodsham astronomical regulator. As well, the remaining instruments from Parramatta Observatory that a governor of the state of New South Wales, Sir Thomas Brisbane, set up in 1821 are on display. This is probably the most significant group of historic scientific instruments in Australia and includes a Reichenbach, Utzschneider and Liebherr repeating circle and a Breguet and Son regulator purchased by Brisbane in 1818.

Other significant instruments are in storage or display off-site including a Grubb astrograph originally used at Melbourne Observatory and a 15-cm Grubb refractor ordered for the 1882 transit of Venus.

Fig. 5: The 1874 refractor in the South Dome. Photograph © Powerhouse Museum


Fig. 6: The Reichenbach, Utzschneider and Liebherr repeating circle. Photograph © Powerhouse Museum


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Sydney Observatory was established at the instigation of a new Governor Sir William Denison in 1855. Its main purpose was to provide time to ships in Sydney Harbour with a time ball and the location on a centrally-located hill was chosen accordingly. The first Government Astronomer was Rev William Scott, a Cambridge mathematician selected by the Astronomer Royal. By April 1858 the building was sufficiently completed that Scott and his family could move in and by June of the same year Scott could start observations and regularly dropping the time ball.

Besides time and astronomical observations the Observatory had a variety of other functions including meteorology. Under the leadership of Henry Chamberlain Russell the Observatory made successful and useful observations of the 1874 transit of Venus from a number of locations in the state of New South Wales. Russell’s illustrated book on these observations is widely known world-wide.

It was also Russell who in 1887 on behalf of Sydney Observatory undertook the mapping of a large zone of the sky for the International Astrographic Catalogue project. Russell designed a telescope for the purpose, only ordering the 33-cm lens from Grubb of Dublin. While waiting for the lens to arrive Russell in 1890 used a portrait camera to take long-exposure photographs of the Magellanic clouds, Eta Carinae and other features of the southern sky.

During the 20th century the Observatory’s influence waned as functions such as meteorology were transferred to other organisations. The Astrographic Catalogue work continued, however, until its completion in 1964, despite one or two attempts by the State Government to close the Observatory. There was then a brief renaissance with work beginning on observing projects such as accurate positions of minor planets, proper motions of star clusters and a new southern sky catalogue. In 1982 the New South Wales State Government placed the Observatory under the auspices of a large local museum, the Museum of Applied Arts and Sciences, better known today as the Powerhouse Museum, and astronomical research was discontinued.


Cultural and symbolic dimension 
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Sydney Observatory’s elevated position near the centre of the city of Sydney gave it significant public prominence, at least until the advent of high-rise office buildings from the 1960s onwards. Its role in meteorological observation until 1908 and time dissemination right up to becoming part of a museum in 1982 is so ingrained in the public consciousness that even today there are people who assume that those roles continue. Scientifically, the Observatory’s completion of the Sydney Zone of the Astrographic Catalogue is its major legacy although there were others, such as Russell’s book of the 1874 transit of Venus, Russell’s 1890 photographs of the southern sky and the 1983 Sydney Southern Star Catalogue. During the second half of the 19th century Sydney Observatory and its sister observatory in Melbourne in the state of Victoria were the two leading astronomical institutions in Australia.


Comparative analysis 
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Sydney Observatory is in some ways a smaller version of the Royal Observatory, Greenwich, but transplanted to a very different colonial context. In the British Colony of New South Wales, Sydney Observatory had a wide range of roles to play: in addition to purely astronomical research, it provided time to the Colony, carried out meteorological recording and forecasting, had involvement in surveying, and made tidal, magnetic and seismological observations. In Australia only Melbourne Observatory, the buildings of which are still extant, has a comparable range of activities in its history.

Sydney Observatory is the earliest substantial observatory in Australia and is relatively complete in the preservation of its buildings and its instruments. Dawes Observatory (1788) and Parramatta Observatory (1822) are both extinct. Sydney Observatory (1858) pre-dates Melbourne Observatory (1863) and Perth Observatory (1897). Sydney Observatory holds the historic astronomy collection from Parramatta Observatory as well as from its own scientific endeavours.

Sydney Observatory has one of the few operating time balls in the world and is one of the even fewer places still utilising the original mechanism. The Royal Observatory, Greenwich has an operating time ball, though with a different (chain hoist) mechanism. There is another time ball at Edinburgh on top of the Nelson Monument on Calton Hill, while another at Lyttleton in New Zealand has been demolished after suffering severe damage in the earthquakes of September 2010 and February 2011.

Located on the north side of the city of Sydney, near the harbour, and on the highest natural landform in colonial Sydney, the site of Sydney Observatory is unique as prior to the Observatory’s establishment in the 1850s it had the Colony’s first windmill, a military fort and a signal station that continued operating until the 1930s. There are important archaeological remnants on the site, some of which are still below the ground. The surrounding park and the location on Observatory Hill provide substantial protection for the Observatory’s heritage curtilage.

Since the 1980s Sydney Observatory has been successfully transformed from a 19th century style research observatory into a museum of astronomy and a public observatory with a highly active educational program. Possibly only that at the Royal Observatory, Greenwich is comparable to this transformation, albeit on a larger scale, but without the extensive public telescope viewings conducted at Sydney Observatory.


Authenticity and integrity 
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The main façade of the Observatory building retains its original appearance with additions in the late 1870s of an extra wing and telescope dome in the observatory part of the building and an enlarged living room with a balcony on top of it in the residence section. The time ball as modified by Henry Chamberlain Russell in the 1870s or 80s is on the roof of the Observatory’s tower and is still dropped regularly using its original mechanism in the tower below. The two main instruments are in situ in their original locations: the 29-cm refractor by Hugo Schroeder of Hamburg installed in 1874 is in the south dome, while the 15-cm transit circle by Grubb is in the transit room where it was installed in January 1877. Both instruments have recently undergone careful and professional restoration.

The interior of the building has been restored with some modifications including the demolition of an extraneous 1907 addition in the rear courtyard. The building now houses exhibits on astronomy and meteorology with an emphasis on the Observatory’s own history. The latter displays are illustrated with a variety of significant instruments and clocks.

Fig. 7: The 1880 plan of Sydney Observatory and its grounds. Photograph Nick Lomb © Powerhouse Museum


Fig. 8: An aerial view of Sydney Observatory in 2009. Photograph Geoff Wyatt © Powerhouse Museum


The grounds of the Observatory have been landscaped back to their 19th century appearance following an 1880 plan published by Henry Chamberlain Russell. A thermometer shed originally built in 1865 has been recreated above the original south marker for the transit circle. A stone survey marker from Russell’s time is still in the grounds. A 1950s brick telescope dome has been demolished and there are plans for a new modern, but more sympathetically-designed telescope dome that would also showcase the Grubb astrographic telescope that is now in storage.


Documentation and archives 
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There have been a number of papers and publications on the history and heritage of Sydney Observatory such as Wood (1958), Wood (1981), Pickett and Lomb (2001) and Kerr (2002). The Observatory’s extensive archives have been deposited with the New South Wales State Records for preservation and accessibility. The instruments used at Sydney Observatory during its 120 years plus period of research activity are now museum objects and information on them is freely available online through the Powerhouse Museum Collection Database.



Present use 
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Sydney Observatory is a part of the Museum of Applied Arts and Sciences, better known as the Powerhouse Museum. It is a public observatory and a museum of astronomy and meteorology.


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Sydney Observatory is on the State Heritage Register in New South Wales.


State of conservation 
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A major refurbishment and renovation was carried out in the late 1980s under the supervision of a conservation architect. Further improvements have since been made and, in particular, a long-term conservation project has recently been completed on the soft Sydney sandstone fabric of the building.


Context and environment 
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The hill on which Sydney Observatory is built had a number of significant uses prior to its establishment. The first windmill in the Colony was built there in 1797, but was demolished prior to the building of the Observatory. Its archaeological remains are believed to lie under the Observatory grounds. The construction of a military fort, Fort Phillip, was begun on the hill in 1804. Only part of this fort was completed with some of the completed parts demolished in the 1850s to make way for the Observatory. A powder magazine was added to the fort in 1815 by the most significant architect of early Sydney, Francis Greenway. Again this was demolished to make way for the Observatory’s construction. From the early 1800s signalling was carried out between the hill and a signal station at the entrance to Sydney Harbour. As the volume and complexity of the signalling increased, the Fort Phillip Signal Station was built for this work. This station was restored in 2008 with one of the highlights being the reconstruction of one of the two tall signal masts that flanked the building until 1939. This station is now part of the Observatory complex as is the signal station messenger’s cottage.

Fig. 9: A model of the Sydney Observatory site showing the Observatory building and Fort Phillip Signal Station flanked by the two signal masts
demolished in 1939; the southern (front) mast was reconstructed in 2008. Photograph Nick Lomb © Powerhouse Museum


Archaeological / historical / heritage research 
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Recent archaeological work has uncovered extra parts of the military fort as well as the footings of the original 1890 dome for the astrographic telescope. This dome was made of corrugated iron with the walls revolving on cannon balls.

There have been a number of papers and publications on the history and heritage of Sydney Observatory such as Wood (1958), Wood (1981), Pickett and Lomb (2001) and Kerr (2002). However, much new information has been collected in recent years including unpublished photographs and there is a plan to utilise these for a new popular book on the Observatory’s history.

The instruments used at Sydney Observatory have become museum objects and are the subject of ongoing assessment and research.


Main threats or potential threats 
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The Observatory in its present state seems well established, but as part of a large publicly-funded museum it must compete with the rest of the organisation for progressively shrinking resources. Light pollution in an increasingly built up area is a growing problem for the evening public viewings provided by the Observatory and there is even the possibility of new buildings blocking the excellent sight lines towards the western horizon long enjoyed by the Observatory.


Management, interpretation and outreach 
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Sydney Observatory is part of a large local museum, the Powerhouse Museum. It is now a public observatory and a museum of astronomy that also interprets Indigenous Astronomy through exhibitions and educational programs.

During term time school groups regularly visit during the day for sessions on astronomy or meteorology that can include visits to the 3D Space Theatre, the small planetarium with its new digital projector, the 1874 refractor and the modern 40-cm Schmidt-Cassegrain reflector for views, if the weather is clear, of the Sun through a hydrogen alpha filter and/or daytime views of the Moon or bright planets. The public can visit anytime during the day and can choose to take a tour to the 3D Space Theatre and the telescope domes. At night there are observing sessions held on six evenings a week.



Bibliography (books and published articles) 
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Kerr, James Semple (2002). Sydney Observatory: a conservation plan for the site and its structures (revised edition). Museum of Applied Arts and Sciences.

Pickett, Charles and Lomb, Nick (2001). Observer and Observed: a pictorial history of Sydney Observatory and Observatory Hill. Powerhouse Publishing.

Russell, Roslyn (2008). Two People and a place: the family who lived in Sydney Observatory. Roslyn Russell Museum Services, Yarralumla

Wood, Harley (1958). Sydney Observatory: 1858 to 1958. Sydney Observatory Papers No 31.

Wood, Harley (1981). Sydney Observatory: 1958 to 1981. Sydney Observatory papers No 91.


Links to external sites 
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Sydney Observatory website


Entity Data

Thematic essay: Astronomy from the Renaissance to the mid-twentieth century

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