Kodaikanal Observatory as a potential world astronomy heritage site

Colloquium given at Indian  Institute of Astrophysics Bangalore, 25 September 2012

Rajesh Kochhar

President IAU Commission 41: History of Astronomy

Indian Institute of Science Education and Research Mohali

[email protected]

As is well known, Unesco has a mission to safeguard and preserve world heritage sites. Towards this end, it prepares a World Heritage List, in which cultural properties from all over are inscribed (that is included) . Additionally, Unesco encourages international cooperation in heritage conservation. Unesco has now undertaken a Thematic Initiative on ‘Astronomy and World Heritage’. It has enlisted technical assistance from International Astronomical Union for this purpose. Within IAU, the responsibility has been entrusted to Commission 41: History of Astronomy. Phase I of this Initiative aims at ‘acquiring an in-depth knowledge of the outstanding properties connected with astronomy in all geographical regions through their identification, study and inclusion of the most representative of these properties on the national tentative lists. Phase II aims at promoting the most outstanding of these properties which recognize and celebrate achievements in science through their inscription on the World Heritage List.

In simpler words, an astronomical property must first enter its nation’s tentative list and then campaign for inscription in the World List. Note that Unesco does not deal with individuals, only with member countries.


You are all familiar with the rust-free iron pillar near Qutub Minar at Mehrauli in Delhi. It is famous the world over for its metallurgy. What is not so well known is its astronomical significance. It was brought to Delhi in relatively recent times, that is 1233 CE. It was originally installed in  about 400CE in Udaigiri, Central India, on Tropic of Cancer, as a gnomon. If this pillar had remained at its original location, it would have been an obvious choice as a world astronomical heritage property.


As things stand, I think the only candidate for astronomical world heritage list from India would be the Solar Physics Observatory Kodaikanal ( est 1899 ), which now has solar picture data with the same instrument for the longest period in the world (since 1912), except for some short interruptions due to maintenance/ upgradation.


Since you are all practitioners of science ( and not merely historians), I will try to place Kodaikanal in the larger context of development of  solar physics as a scientific discipline.

By the middle of the 19th century, physical astronomy, as distinct from positional astronomy, had already taken some shape, thanks to the advent of  solar spectroscopy and photography. There were a number of solar eclipses in quick succession and visible from India : 1868, 1871 and 1872. These eclipses brought observers from Europe into India, and gave a fillip to solar instrumentation and studies the world over. In 1868, the French astrophysicist Pierre Jules Cesar Janssen discovered helium from Guntur . During his post-eclipse stay at Simla, Janssen created the first spectro-helioscope, which facilitated daily examination of the sun.

Then came the 1874 Transit of Venus. The scientists’ agenda for it ran deep. What was advertised was the brief passage of Venus in front of the solar disc; what was planned was a long-term study of the disc itself.

British (and European) solar physicists wanted photograph of the sun for each day of the year. Since this was impossible in Europe’s weather conditions, data was needed from the colonies.

The British Association for the Advancement of Science passed a resolution asking the Government of India to make arrangements for observing the event and to provide instruments which were afterwards to be transferred to a solar observatory. Such was the prestige enjoyed by science and scientists in Europe at the time that the British Empire, as the owner of the most of the world’s sunshine, agreed to help, though partially.


The 1874 transit eventually led to regular solar physics studies in India, even though the exercise took 25 years. The initiative came from the influential British  scientist of the time , Sir Norman Lockyer.To sum up in advance, the step-wise developments were as follows. First, express arrangements were made for the observation of the 1874 event from Roorkee. Next, interim facilities were created at Dehra Dun and Poona for collection of data and its transmission to Europe. Finally, a permanent solar physics research facility was set up at Kodaikanal.


The 1874 event

 It is noteworthy that Survey of India ( and not Madras Observatory) was asked to make transit  observations. More than 100 photos of the sun were taken at Roorkee  and sent to the Astronomer Royal Sir George Biddell  Airy. Photos from all over were reduced by Captain G. L. Tupman who wrote: ‘There is only one really sharp image in the whole collection, including the Indian and Australian contingents, and that is one of Captain Waterhouse’s wet plates taken at Roorkee’.


Dehra Dun Observatory (1878-1925)

 Lockyer used his equation with Lord Salisbury, the Secretary of State for India, for making arrangement for solar photography in India. Salisbury wrote to the Viceroy on 28 September 1877: ‘Having considered the suggestions made by Mr. Lockyer, and viewing that a study of the conditions of the sun’s disc in relation to terrestrial phenomenon has become an important part of physical investigation, I have thought it desirable to assent to the employment for a limited period of a person qualified to obtain photographs of the sun’s disc by the aid of the instrument now in India’.  From the technical details given in the letter , it is clear that it was drafted by Lockyer himself. Accordingly, starting from early 1878,  solar photographs were regularly taken at Dehra Dun  under the auspices of Survey of India, and sent to England every week. Dehra Dun continued solar photography till 1925, but more out of a sense of duty than enthusiasm.


The larger of the two photoheliographs fell into disuse, and in 1898, Lockyer was stung by on-the-spot discovery that ‘the dome has been taken possession of by bees’.The arrangement was discontinued in 1925, and equipment sent to Kodaikanal.


St Xavier’s College Observatory, Calcutta (1879)

 Sunny India caught the attention of astronomers in the continent also. The Italian transit-of-Venus team led by Professor P. Tacchini of Palermo Observatory stationed itself in Bengal, its Chief instrument being the spectroscope, `an instrument not recognized in the equipment of any of the English parties’. A co-opted member of the Italian team was the Belgian Jesuit Father Eugene Lafont (1837-1908), the popular professor of science at the elitist   St. Xavier’s College. Lafont was  no researcher himself was an inspiring educator and science communicator.

Tacchini suggested to Lafont ‘the advisability of erecting a Solar Observatory in Calcutta, in order to supplement the Observations made in Europe, by filling up the gaps caused in the series of solar records by bad weather’. Lafont used his influence with Europeans, Anglo-Indians  (half-castes), rajas, zamindars, and Indian men of note, and soon collected  a substantial sum of Rs 21000 through donations, including Rs 7000 from the Lieutenant Governor of Bengal.

A  9 in refractor by Steinhill of Munich was purchased and housed in a spacious dome constructed for the purpose.

No research or teaching use was ever made of  this facility. This is unfortunate. If the experiment had succeeded, observational astronomy might have become part  of Indian education system. As it is, astronomy has largely remained decoupled from  college/ university teaching.



Takhtasinghji’s Observatory Poona  (1888-1912)

      It was a Government Observatory, named after the principal funder, Maharaja of a princely state, Bhavnagar. It was India’s first modern astrophysical observatory. Unfortunately, it was created for an individual and did not last long. The original plan was to establish a spectroscopic laboratory at Elphinstone College Bombay for use by the students. The initiator of the proposal was a lecturer in the College, Kavasji Dadabhai Naegamvala (1857-1938), who obtained seed money of Rs 5000 from the Maharaja of Bhavnagar and a matching grant from the Bombay Government.  While in England in 1884 for buying the equipment,  he was persuaded by the Astronomer Royal and Lockyer to build a spectroscopic observatory instead.


Since Poona was a better astronomical site than Bombay, in 1885 Naegamvala was transferred  there to College of Science where the Observatory came up in 1888. Its chief instrument was a 16½ inch aperture silver-on-parabolic glass Newtonian  made by Grubb. In addition, Lockyer equipped Poona as a satellite facility. A six-inch Cooke equatorial purchased by the Government for the 1874 transit observation from India had been  loaned to Lockyer’s Observatory in South Kensington.


The India Office also purchased two spectroscopes from Hilger (one solar, the other stellar) for his use. The equatorial and the spectroscopes were given to Naegamvala so that he could observe with them and send raw data to Lockyer. Similarly, data was received  by Lockyer and more generally in England from Kodaikanal and Mauritius.


Not surprisingly, relationship between Poona and South Kensington was non-symmetrical. Whenever South Kensington found fault with data collection at Poona, it did not write directly to Naegamvala, but formally complained to his British superiors. Yet, when Kodaikanal Observatory was being planned, Lockyer suggested Naegamvala’s name for the directorship. The position was however offered to an Englishman, Charles Michie Smith, a non-descript physics professor at Madras. Lockyer and Astronomer Royal constituted two independent centres of power in England, and Kodaikanal came under the latter’s sphere of influence.


Naegamvala took observations till the very last date of his employment, 11 January 1912. The Observatory was officially abolished on the day of his retirement and  all equipment was sent to Kodaikanal. Thus instead of creating a permanent educational facility, a temporary research centre was created for the primary benefit of European solar physicists.


Kodaikanal Observatory (1899)

       If the 1874 transit of Venus was important for solar physicists, so was the severe famine of 1876-77 in the Madras Presidency. Monsoons fail at times, but the severity of famines was particularly high in the colonial period because of large-scale export of food grains from India to Britain  in utter disregard of local requirements. Astronomers of course would not worry about avoiding famines, but in predicting monsoon behaviour. In 1879, Lockyer presented a report to the Indian Famine Commission claiming that famines were correlated with sunspot minima.

There is no doubt that Lockyer and many others genuinely believed in a correlation with solar activity and terrestrial weather. But  it is also a fact that the practical benefits to be derived from a study of the sun were exaggerated to gain Government support. In 1881, Government of India’s chief meteorologist Henry Francis Blanford reported to the Famine Commission that no such simple sunspot-monsoon correlation as suggested by Lockyer existed.


In any case, the Government decided to go ahead with the Solar Observatory. It was however decided to wait till the neurotic Madras Astronomer Pogson was dead. This happened in 1890.

Kodaikanal started shakily. The first task was the acquisition of instruments; they came from a variety of sources.

A photoheliograph (Dallmeyer No. 4) originally made for the 1874 transit was given on loan by Greenwich to Kodaikanal. It was used till 1912. Madras had acquired a 6 in telescope on English mounting, by Lerebours and Secretan of Paris, in 1850. It was remodelled in 1898 by Grubb of Dublin who provided it with an electric drive, and mounted a 5 in aperture a 5 in aperture  Grubb photographic lens on the frame. These and other pictures have now been digitized.


The most important event in the Kodaikanl Observatory’s history was the arrival of George Evershed in 1907, who chose to come to India  no doubt to be able to work in solitary splendour. Kodaikanal rose to great heights under him. His first task was the installation of Ca-K spectroheliograph that had been received in 1904, from Cambridge Scientific Instruments Company. His 1909 discovery of the radial flow in sun spots_ the Evershed Effect_ is the only major discovery ever made from Kodaikanal.In 1911, he made an auxiliary specroheliograph and bolted it to the existing instrument. The Sun could now be photographed not only in Ca-K light but also in H-alpha.


This is the only time a state-of-art pure astronomical instrument was ever made in India.

These old twin spectroheliographs are no longer in use. The H-alpha pictures were discontinued in about 2005, and  the Ca-K  in about 2007. In the mean time, in 1995, as a back-up, Ca-K line filtergrams using a CCD camera were begun.      Finally, in 2008 a newly constructed  twin telescope was commissioned to take pictures in Ca-K and white light. In other words, Kodaikanal does not take H-alpha pictures any more. It takes Ca-K pictures all right, but with a new equipment, as in the Spectro building and white-light pictures at two places ( North Dome and Spectro).In 1933, a Hale spectrohelioscope was received as a gift from Mount Wilson Observatory.


The Spectroheliograph building, known locally as Spectro, has a priceless clock from the 18th century. It is among the dozen odd gridiron pendulum clocks made by John Shelton for the 1761 or 1769 ( probably the latter) transit of Venus. It is not known when and how one of the Sheltons ended in India. The clock was one of the original instruments at Madras Observatory (est 1787). It was transferred to Kodaikanal in 1899. It is still working, and is in use as an ordinary clock.


International Geophysical Year 1957-1958 provided an opportunity for ordering three new instruments. Two of these, Lyot heliograph, and Lyot coronograph, were never really utilized. The third instrument, acquired on turn-key basis, was the Solar Tunnel Telescope which was commissioned by M. K. Vainu Bappu, who joined as Director in 1961. This was the last time Kodaikanal got a new instrument.Over the years many minor instruments were obtained; and new temporary  ctivities initiated ( radio, magnetic/ionospheric). At present, the Tunnel Telescope, Spectro, and the North Dome are the only regular activity centres of  Kodaikanal Observatory.

Kodaikanal was never a well-endowed Observatory. Told instruments cwere often canabalized o meet current requirements, for example an eclipse expedition.There was therefore lot of improvisation; cutting up of old instruments to make new ones for solar eclipse expeditions, e. g.

About 25 years ago, I traced the history of almost every instrument, or parts thereof, that was in actual existence or was mentioned  in the Store’s Stock Register. Many of these details have been published ( eg in Vistas in Astronomy). Here I have drawn attention to only some of them.

  • Indian Institute of Astrophysics Bangalore ( whose field station Kodaikanal Observatory is) has a priceless instrumentation heritage. It deserves to be documented case by case  and preserved.
  •  Kodaikanal Observatory has always been an important feature on the  town’s tourist map. The Observatory however needs to revamp its Outreach Programme, and ,make it more attractive and interactive.
  • Many buildings in the Kodaikanal campus are lying unused. Utilizing them for a combination of heritage, curriculum-based education and science popularization will help preserve the buildings also. The Kodaikanal Observatory needs to be protected not only as cultural property but as real estate also.


Concluding remarks

Kodaikanal Observatory is a respected name in the world solar physics. Many better-known observatories have discontinued their old programmes, or even shifted to new locations, and become more high tech.

IIA should prepare a detailed dossier on the Observatory. Persuade  India’s Ministry of Human Resource Development ( Indian node for Unesco) to include it in the national list.

Then work towards getting it inscribed in the Unesco World Heritage List.






























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