Why did the British photograph the sun every day from Dehradun for 47 years?

On an appropriately melancholic winter morning, I am contemplating a Gothic structure, part facade, part foliage. The architectural style betrays the building’s age while the overgrowth speaks to its disuse. As the shadows dapple its crumbling walls, the paneless, pointy windows and lightless interiors evoke the vision of a séance rather than science.

This ruin, inside the 250-year-old Survey of India, Dehradun, was in all likelihood the site of one of the most ambitious astronomical undertakings of the late 19th and early 20th centuries. From 1878 to 1925, photographs of the sun were taken here twice every day and dispatched weekly to Britain.

At the Survey of India campus are a number of defunct observatories. While the fading sign in front of the derelict Hennessey Observatory states that solar photography commenced there in 1883, no information about the five preceding years is readily available. The only surviving example of this series at the National Survey Museum, from 1905, attributes it to a mysterious Walker Observatory, which is no longer identified. After trawling through the archive and scouring the grounds with me, Arun Kumar, Officer Surveyor in-charge of the Museum, concludes that the Gothic ruin across it is in fact the Walker Observatory from which a regular programme of solar imaging first began in India.

What was the broader context of this endeavour? What was the infrastructure that made it possible? Why was it undertaken at all? The two Dehradun observatories generated thousands of photographs of a single star. Though only one remains, it betokens a narrative that entwines scientific history, early astrophotography and colonial politics. On the one hand, the field of astronomy harnessed new optical and lens-based technologies to produce knowledge as spectacle, pivoting from imagining the heavens to imaging them. At the same time, the colonial state looked to use data collected through scientific and mathematical studies for more efficient governance. The sun played a prominent role in both these developments.

The first photograph of the sun was taken in 1845, the first photoheliograph installed at Kew Observatory, London, in 1858, the spectroscope invented in 1860 and, in the shadow of eclipses and the expeditions organised to record them, emerged the modern field of solar physics. In India too, modern astronomical research, under the auspices of the British administration, was not unknown (the Madras Observatory goes back to 1792, after all). In a 2012 lecture at an International Astronomical Union conference, Rajesh Kocchar, a professor at Panjab University’s mathematics department, asserted that the 1874 transit of Venus across the sun marked the consolidation of solar physics in India. The event had a logistical effect on the Dehradun project as well: the instrument used by James Tennant in Roorkee to observe Venus’ movements was later used to shoot the sun at Walker Observatory.

During the late 19th century, there was considerable interest in the sun among astronomers, especially in Britain due to William Herschel’s theory linking sunspots and wheat cultivation. Though inaccurate, the claim eventually contributed to the discovery of the eleven-year length of sunspot cycles. Concurrent with this interest, the visual techniques of science were becoming increasingly sophisticated and informative. Here too, Herschel proved influential – his solar spectrum images were among the first shots of our star. In her essay Staging the Heavens: Astrophysics and Popular Astronomy in the Late Nineteenth Century, Charlotte Bigg, a researcher at the Centre National de la Recherche Scientifique, Centre Alexandre Koyré, cites the spectroscope, photographic camera and photometer as enhancers of telescopic observation, “[t]he images produced by these new representational technologies” enabling both scholarship and its dissemination among non-specialists.

Popularising science

The scientific interest in the sun soon captured the public’s imagination as well. British astronomer Norman Lockyer, discoverer of helium and editor of Nature magazine, was a leading figure in both the refinement of a scientific approach to sunspotting as well as the mainstreaming of it. Bigg identifies Lockyer as a member of the new class of “popular scientists” who “distanced themselves from the disciplines of precision, observation and calculation characteristic of positional astronomy and quantitative astrophysics…[and] sought to convince their audiences by combining aesthetics and science.” Although the solar photographs taken in Dehradun were not exhibited for wide viewing, they do indicate a turn, also noted by Kocchar, away from an abstract, mathematical study of celestial objects towards physical astronomy.

Lockyer was also among the first members of the Committee for Solar Physics set up in 1879, funded through the Industry, Science and Art Department. It was this Committee that was responsible for the initiation of the solar photography programme at Dehradun, to accompany three other sites: initially Kew and the Royal Observatory, Greenwich, and, some time later, the Royal Alfred Observatory, Mauritius. According to the Survey of India’s reports, solar photography at Dehradun was begun “at the request of the Industry, Science and Art Department in 1877”, obviously advancing the Committee’s scientific agenda. From the letters that Committee members wrote to the British Parliament in that year, we glean a number of things: that Norman Lockyer trained a sapper called M Meins in the practice of solar photography for work in India and that he was to “be employed…under the direction of [Surveyor General] Colonel Walker” (after whom the Gothic observatory is named) at a monthly salary of 1 shilling and 9 ½ pence. He was to be equipped with chemicals and a telescope tube that would replace the one on the photoheliograph used by Tennant during the transit of Venus three years prior.

The Survey of India’s annual reports reveal that things didn’t quite go according to plan. Firstly, Meins’ telescope didn’t make it to India for over six months after he did. He ended up having to use Tennant’s, at Calcutta for the first couple of months and, subsequently, at Dehradun. Secondly, Meins died a year after his arrival. A letter from the chairman of the Committee for Solar Physics to the Under Secretary of State for India asks if it made more sense to train in photography the already-acclimated “intelligent natives” of the Survey of India. No Indian photographer is named in the 46 annual reports of the Survey during the period of the programme. Meins’ successors were all natives of Britain: LH Clarke, CF Guthrie, B Rowland and RW Foster. The Indians who are part of this work are grouped under the designation of khalāsi, a term for porters which implies that they were probably personnel who handled and carried the bulky equipment.

What was this equipment the khalāsis handled? Supplementing the old photoheliograph, a new one, of the famous Dallmeyer brand, was imported to Dehradun in 1881. Although capable of generating larger images, it was also more expensive to operate because of the costs of glass and chemicals involved, and was thus “used only when special features were available on the sun’s surface”.

The photographic processes at the observatories paralleled shifts in practice outside. For the first 20 years of the solar photograph series, they were processed using the wet collodion method: “a bromo-iodized collodion has been used in connection with iron,” according to the annual reports of the Royal Observatory, Greenwich. From around 1900, dry plates began to be used, a move that “promises success”. Every week, the negatives would be dispatched to the Committee for Solar Physics, which then forwarded them to Greenwich to be measured, corrected and archived. Of the prints, nothing else is known save for the single example at the Museum. The statement of expenditure in the Survey of India reports itemised wages, chemicals (locally sourced and imported), silver prints and negatives and shipping and landing – a few thousand rupees annually, all charged to the Industry, Science and Art Department.

Political imperative

But though the spirit of scientific enquiry was a factor, there was another, more expedient, context for this work. This curious visual diary triangulating between Britain, India and Mauritius formed part of a colonial governing apparatus. In the same way that cartographic surveys of the land helped map and directly control territories, astrographical surveys of the sun indirectly facilitated their administration.

As Herschel’s work indicates, one of the ideas circulating in scientific discourse at this time was the link between the sun and terrestrial weather (turns out it’s more complicated). British meteorologists and solar physicists of the era were conducting tests to establish a relationship between sunspots and rainfall. In her book Predicting the Weather: Victorians and the Science of Meteorology, York University professor Katharine Anderson elaborates, “These analyses bound physical astronomy and meteorology tightly together as models of modern research science – the former drawing on the instrumental advances of photography and spectroscopy, the latter moving away from ‘a collection of mere statistics’ into a physical science or the ‘Meteorology of the Future,’ in the grandiose language of Nature’s editor, Norman Lockyer, in 1872.”

In 1877, Lockyer and an associate of his, WW Hunter, a statistician and civil servant in India, co-authored a paper called Famines and Sun-Spots. In it, they enumerate the scientists, including Lockyer himself, studying the links between the periods of solar-spot cycles, changes in water body levels and annual precipitation. One such example of research was focused on Mussoorie, by Surveyor General JBN Hennessey, after whom the second Dehradun solar observatory is named. Another such research was conducted by Charles Meldrum of the Mauritius observatory. Hunter had been greatly affected by his time in the administration during the famines in Orissa in 1866 and Madras in 1877, characterising himself in the essay as “a statistician, whose duty it was to collect and tabulate all collateral evidence bearing upon the discovery which he made regarding the cyclic character of the factors of the Madras rainfall”.

This astronomer-administrator collaboration on paper is an indicator of the relationship between scientific technology and the colonial government. As Anderson notes, the loss of taxes and credit from a prime agrarian economy like India was deeply undesirable: “Control of famine meant India could be governed more effectively.” If scientific data could accomplish this, then it served the imperial cause. In their letters, scientists in the Committee for Solar Physics try to persuade British parliamentarians to fund a solar observatory in Britain by alluding to famines and cyclones in India. They seem to be suggesting that their meteorological inquiries have governmental use. The sun that apparently never set upon the British Empire could be the very means of ensuring its persistence.

Southward migration

But with all the sunshine in India, why choose Dehradun? Madras’ observatory was older, and it was the site of the famine that had galvanised Hunter into writing the paper with Lockyer. Indeed, Anderson informs us that NR Pogson, the Government Astronomer at Madras, introduced Hunter to the idea that famines might be predicted by tracking solar-spot cycles. Nevertheless, topographical considerations made Dehradun a better candidate for solar photography. The Committee for Solar Physics argues that in north India, there are “the advantages of great elevation and a low latitude…render easy the inauguration of a series of systematic observations”. But the project did eventually migrate south. In 1899, a solar observatory was set up in Kodaikanal and, in 1925, the sun diary began to be kept there instead. In the Survey of India’s Geodetic Report of that year, the reason cited was its lack of relevance to the Survey of India’s activities, high cost and the superior infrastructure of the Kodaikanal Observatory.

The solar photographs were available for public viewing only once in nearly five decades. They formed part of a Survey of India display at the Calcutta International Exhibition of 1883-’84. Scholars have pointed out that the exhibition ultimately ended up being rejected by white communities within India and governments worldwide for its seeming challenge to the colonial order. But it had been conceived as an opportunity to impress the world with the achievements and resources of the Empire and to present a successful image of the prized colony. The Survey of India’s solar photographs went on to win a silver medal at the exhibition, very briefly existing as objects of aesthetic consumption rather than data-driven examination.

Even today, the Survey of India conducts solar observations. Bhaskar Sharma, Officer Surveyor at the Data Centre, explained, “We do this for calculating azimuths and the geomagnetic north. Though we normally use the pole star because its movement is restricted and therefore much more accurate, we can only make use of it at night.” Daily solar photographs continue to be taken at Kodaikanal, that series having surpassed the Dehradun one by 77 years (and counting). But as two of the first stations in the world to capture the sun every day, the legacy of the Walker and Hennessey Observatories cannot be discounted. The Committee for Solar Physics certainly seemed to think so back in 1925: “...astronomical science is very deeply indebted to the Survey of India for the excellent scientific material it has contributed to the study of its problems during almost half a century.”

As he walks me out of the Survey campus, Kumar tells me, having just remembered, that the orders for the demolition of the Walker Observatory have come in.

The writer would like to thank for their help Arun Kumar, Surveyor Officer in-charge of the National Survey Museum, Dr Christiaan Sterken, President, International Astronomical Union’s Commission C3 History of Astronomy, and Madeleine Smith-Spanier, Database Management Assistant, International Astronomical Union.

Kamayani Sharma is an independent writer, researcher and podcaster based in New Delhi. She is a Kalpalata Fellow in Visual Culture Writing for 2022.