I recently inspected old telescopes in Melbourne, Australia, which included the Astrograph House and The Melbourne Observatory. As I photographed the observatories, I got a few funny looks from people strolling by who had no clue how these facilities contributed to our knowledge of the solar system.
The original observatory and related buildings were constructed starting in 1861. The Astrograph House was constructed in 1889 for the purpose of photographing and mapping the southern sky.
The Melbourne Observatory joined with 17 other observatories worldwide to begin a project called Carte de Ciel, (Map of the Sky). In addition to creating a map of the sky, accurate measurements were needed to assist in defining the distances of stars from earth. This tedious work involved accurate measurement of the position and brightness of over one and a half million stars.
Over 50,000 were measured and catalogued here alone. For this work, young women were employed to work as “computers” for a grand total of £75 per year! The observatory and telescope house continued to operate as an active facility until 1945.
In 1869, the largest steerable telescope in the world was located at the observatory, a 48-inch Cassegrain called the Great Melbourne Telescope. It was built in Ireland and was the second largest telescope in the world.
This gigantic telescope had problems. Due to its size, even the slightest wind would induce unacceptable movement of the telescope, and it was deemed unsuitable for photography, although it was used for spectroscopic observation and early photography of nebulae. There was also a problem resurfacing the mirror. In 1890, the telescope was decommissioned.
The Great Melbourne Telescope, eventually transferred to the National Observatory at Mt. Stromlo (near Canberra, Australia) was substantially destroyed in bush fires tin 2003. Fortunately, the mirror survived. Currently, an effort is underway to restore the telescope and return it to the Melbourne Observatory which is being restored and will be open to the public soon.
An adjacent building housed two solar telescopes. This facility, the South Equatorial and Photoheliograph House, was built to observe and measure the transits of Venus that occurred in 1874 and 1882 and would last only a few hours.
The transit would allow astronomers to accurately calculate the size of and distance between the Earth and the Sun as well as Venus. The observatory also took daily photographs of the Sun for over 20 years.
This observatory complex is now in the Royal Botanical Gardens, a historic spot. Due to its location, it is doubtful that any useful astronomical research can be derived from such a light-polluted site. It was inspiring to visit the site and consider that in its day, this was an important astronomical facility.