TaareWiki | Site / Transit of Venus Observations by Ankitam Venkata Narsinga Rao in 1874

N. Rathnasree and Sanat Kumar, Nehru Planetarium, New Delhi, India – 110011.

(Appeared in the Indian Journal of History of Science, 39.2 (2004) 231-236)

The story of observations in India, of the 18th century transits of Venus – those of 1761 and 1769, belonged to European observers who traveled to India, to observe the transits. The most poignant of these travelers was, of course, Le Gentil, who missed both the transits after traveling in difficult conditions and waiting away from the home base, all of eight years, from one transit of Venus to the next!

When we come to the 19th century transits of Venus, the 1874 event was visible from India, and gave rise to considerable Astronomical activity in relation to the transit. In addition to the activity of British Astronomers, already in India at that time, or European expeditions to India for the transit, this was the time for Indian Astronomers to make contributory observations for these events. The two Indian names associated with Astronomical observations from this period, related to eclipses, occultations and transits, were those of C. Ragoonathachary and Nursing Row. Perhaps an Indian way of writing their names would be Raghunathachary and Narasinga Rao.

Chintamani Raghunathachary was an assistant to Norman Pogson, the British Government Astronomer and head of the Madras Observatory from 1861-1891. The group’s concentration was in the study of variable stars and asteroids. Raghunathachary’s discovery of the variability of light output from R Reticuli is considered the first observational discovery in modern Astronomy, by an Indian observer. The group also participated in observations of solar eclipses visible from India, the most important of which was the eclipse of August 18, 1868. Spectroscopic observations of this eclipse, done at Guntur, in Andhrapradesh, gave the first indications of the existence of the element Helium, so called because it was first detected in the Sun.

Raghunathachary communicated the results of some of his eclipse observations of 1871 (submitted through Pogson), to the Monthly Notices of the Royal Astronomical Society. He seems to have also been active towards the preparations for the observations of the 1874 transit of Venus. He even bought out a booklet in Urdu for this (Kochar and Narlikar 1993). However, he does not seem to have communicated any observations of the transit – perhaps he had been clouded out, as seems to be indicated from some of the reports by others, of the 1874 Transit of Venus.

The other Indian name associated with observations of eclipses, transits and comets, from this period, is that of Ankitam Venkata Narsinga Rao, a scion of a zamindari family. Considering that his observations were not conducted at an observatory under the support of the British Government in India, it may be worthwhile to trace his biographical details that led to his interest in Astronomy and his ability to do observations with modern European instruments and report his observations in European journals.

A Monthly notices obituary of 1893, gives the following biographical information about Narsinga Rao –

He was born in 1827, his father was a diwan of the nawab of Masulipatam (present day Machilipatnam) and uncle a dubash of the East India Company in Ganjam district. On becoming an orphan, his maternal grandfather bought him up and his education was entrusted to Mr. Porter and then to the Rev. J. Hay, who is considered as the father of modern education in the northern circars. Narsinga Rao worked as a deputy collector with the East India Company, but later resigned on his wife’s inheriting some property, to manage the estate.

He found attached to the property, an observatory equipped with a transit instrument, erected by his father-in-law, G.V. Jugga Rao. It was with the running of this observatory that Narsinga Rao learned the rudiments of Astronomy and built on it, through his correspondence with English Astronomers. He had a new observatory built in 1874 and equipped it with a 6 inch equatorial instrument, a transit circle and a sidereal clock. He also started a photographic laboratory in the town and wished to provide means at his observatory for Astrophotography. His death in June 18, 1892, prevented that.

He had been elected as a fellow of the Royal Astronomical Society in 1871 and the Royal Geographical Society in 1872.

One of the English Astronomers he seems to have been in correspondence with, was Charles Piazzi Smyth of Edinburgh, Astronomer Royal of Scotland and professor at Edinburgh University. Narsinga Rao communicated his observations of the 1868 transit of Mercury visible from India, to Piazzi Smyth, who submitted these observations to the Monthly Notices of the Royal Astronomical Society (Nursing Row 1869, MNRAS 29, 278). Narsinga Rao sketched the location of Mercury, as seen from Visakhapatnam, during the transit –

Figure 1. Narsinga Rao’s sketch of Mercury transiting the Sun, 5th November 1868. His annotations refer to Z as the vertex or the highest point of the Sun, N the north point, B the point of first contact and E the point of last contact.

Narsinga Rao gave the transit timings as

First Contact – 10h 58m 39s

Last Contact – 2h 35m 57s

Presumably, these referred to the second and the third contacts of Mercury which calculated from the Occult Program, for this transit as seen from Visakhapatnam are – 10h 58m 47s Second Contact and 2h 29m 21s. A comparison of his transit path with that obtained through a simulation of the same transit, seen from Visakhapatnam, using Redshift software, is shown below –

He refers to the observation of a ‘wavy tint of light darting from the upper edge, disturbed at times, but continued until the planet had passed some distance from the highest point of the line of transit’ by himself and some European friends present during the observations.

Suspecting this to be an effect of disturbed focus, Narsinga Rao readjusted the focus, changed eyepieces and took several other precautions, but, the phenomenon survived in spite of all this.

Narsinga Rao goes on to state – ‘A scientific friend who was then present remarked to me that he was informed somewhere that the planet, when leaving the Sun’s disk, would have the appearance of a flask’.

By this, he presumably was referring to the blackdrop effect, and seems to have watched out for it and not detected it from his observations.

Piazzi Smyth then comments on these observations and the observer – ‘the writer of the above extract is a hindoo gentleman of Vizagapatnam, whose family has been much given to science through two generations. He possesses an extensive observatory, both Astronomical and Meteorological, and is now about to add to the former with a 6 inch equatorial, with driving clock, micrometer and spectroscope, and to his library all the purchasable volumes of the Monthly Notices of the Royal Astronomical Society. The telescope with which these observations were made has an object glass of 4.28 inches aperture, by the late W.S. Jones, of London and was fitted up in Mr. Nursing Row’s own workshop on a large and original kind of altazimuth stand, supplied with vernier circles, levels and slow motion screw-movements’.

The geographical location of Daba Gardens, Visakhapatnam, where Narsinga Rao’s observatory was situated, was given by him in a note about the Solar eclipse of 1872, to Dr. Huggins, as 170 42’ 9” N and 830 22’ 30” E (Huggins 1872, MNRAS 32, 72).

The instruments mentioned above were obtained and used by Narsinga Rao, for the observations of the 1874 transit of Venus, the results of which he communicated directly to the Monthly notices (Nursing Row 1875 MNRAS 35, 317). The weather was favourable only for the last thirty minutes of the transit, and he succeeded only in observing the egress. He reports the observed timings in Sidereal Time as –

Second Internal contact – 16h 47m 15.4s

Second External Contact – 17h 15m 27.2s

The predicted times from Occult, for Visakhapatnam, on the 9th of December 1874, are (in Sidereal Time)

Second Internal contact – 16h 19m 28s

Second External Contact – 16h 32m 49s

He also refers to an indentation observed on the Sun after the fourth contact– ‘After the second external contact, when the limb of the Sun had resumed its natural appearance of an arc, a slight indentation was directly formed in the Sun’s limb. This indentation was not so dense as that caused by the planet, but was more or less tending towards an ash colour, and was apparently greater in arc than the previous one’. He gives the timings for the disappearance of the indentation as 17h 15m 54s (Sidereal Time).

This indentation could have been a manifestation of the atmosphere of Venus, and it would be interesting to compare the noticing of this with other observations, related to the atmosphere of Venus.

Later, Narsinga Rao also made observations of the great comet of 1882 and submitted his observations to the Monthly notices, which appeared in vol 43 in 1882 and his observations of comet Pons-Brooke in Vol 44, 1884.

It is a great pity that little remains of the indigenous observing efforts of Ankitam Venkata Narsinga Rao other than his publications and some of his instruments displayed at the Visakhapatnam Museum.

References

Kochar, Rajesh and Narlikar, Jayant 1993, Astronomy in India – Past, Present and Future, Published by IUCAA, Pune 411007.

Huggins, 1872, MNRAS 32,72.

Nursing Row, 1875, MNRAS 35, 317.

Nursing Row, 1882, MNRAS 43, 32.

Nursing Row, 1884, MNRAS 44, 255.

Obituary 1893, MNRAS 53Q, 222.

Acknowledgements

NASA Astrophysics Data Service and archives of the Royal Astronomical Society.