For a few months after the transit, newspapers and journals regularly followed updates from the expeditions. Airy apparently sent updates to the press; one list of places to which transit of Venus information should be sent included, among government offices and national observatories, the following: Reuters’ office, the Times, the Daily News, the Standard, the Daily Telegraph, the Athenaeum, Nature, the Smithsonian Institute, the Manchester Courier, the Pall Mall Gazette, the Echo and the Globe. But, in general, press coverage of the enterprise did not last long after the day of the transit. There were a few last attempts to draw some public reaction by reporting spectacular failures, such as a report in the Daily News from mid-January 1875. The supposed disaster caused by the loss of observations in New Zealand and Kerguelen was contrasted with the supposed successes of Lord Lindsay's operation, especially his choice of the ‘almost perfect, theoretically’ long-focus photographic method, which, as the paper suggested, Airy declined out of pride to adopt:

Proctor had written in the Daily News before and he may well have been the author of this piece; the concluding jab at Airy's alleged immunity is characteristic of his style. Either way, it was far too early to make any statements about the relative successes of each country, or about how the British government would react to any failures. While it was true that the Americans had had slightly better luck with the weather, other factors would be much more important in deciding the fate of the research programmes.

On 9 December 1874, in Sydney, New South Wales, a rare transit of Venus happened to coincide with a round of important local elections. In the Sydney Morning Herald for that day, set among articles about ship arrivals, a smoking volcano in the Torres Strait and commodities quotations from Singapore (nutmeg, mace, pepper, pearl sago, tapioca, rice, coffee, cigars, etc.), there is an article entitled ‘Science and Politics’. The article sets out to contrast these two ‘very different phases of human action’. On that morning, at the observatory on Flagstaff Hill, astronomers were straining to time with the utmost precision the passage of the silhouette of Venus as it crawled across the surface of the sun. Sydney was just one of hundreds of spots on the globe where similar observations were being made on that day.

By the late 1850s, the Royal Observatory was running at the high level of efficiency for which, as was described in the previous chapter, Airy's tenure was already well known. After two decades as Astronomer Royal, Airy was a central and powerful figure in British science. He had not entirely avoided controversy. The recent loss of priority of the discovery of Neptune to the French was a huge blow to his public image. Airy's work on ship magnetism had brought him some notoriety as well; a ship was controversially lost just after its compasses had been adjusted according to Airy's method. It was from the operation of Greenwich meridian astronomy, however, that Airy maintained his upstanding character. There was a regular time service and a regular output of astronomical observations. Subjects on which the observatory steadily published included observations of minor planets, tables of the moon's motion, longitude determinations of foreign observatories, and refinements to the instruments of precision astronomy. Against this backdrop of routine observation, Airy introduced plans for attacking the problem of the sun's distance.

The value of the sun's distance (then referred to in terms of solar parallax), was continuously refined throughout the nineteenth century. During the 105-year gap between the eighteenth-and nineteenth-century transits of Venus, astronomers recalculated and reanalysed the 1761 and 1769 observations, sometimes when improved values of longitude for the observation stations were made available, sometimes when new approaches to the selection and combination of observations were developed. As the Edinburgh Review put it in 1873, ‘many restless astronomical spirits … continued to nibble at these figures’. In 1825, Johann Franz Encke produced a parallax of 8˝.54 (⋃154m km / 95.7m mi) by updating the longitude data for the results from the 1761 and 1769 transits. The British Nautical Almanac used this value from 1834 to 1869.

Particle accelerators, space shuttles, the Manhattan Project – these are classic examples of ‘big science’. The term emerged after World War II as a label for the enormous scientific projects of modern times. It is sometimes hard not to see big science as a unique signature of the present day. But of course in a relative historical sense every period has had its own ‘big science’: intellectual or technological projects executed on what was a dramatic scale for the time. Historians, increasingly interested in the historical precedent for today's big science, have begun to talk about the ‘bigger science’ of previous periods. The eighteenth-century transits of Venus are a stock example of early big science. The nineteenth-century transits are not, but only because their story is less well known. In this chapter, the outlines of what was the big science of Victorian times will be presented. The large-scale research programmes of the period share similar characteristics, such as institutional settings, programme designs, public representations and types of personnel involved.

The bigger science of a period often was not the most significant or visible science in historical or even contemporary terms. For example, for the nineteenth century, Charles Darwin does not fit into this category. Neither does Michael Faraday or James Clerk Maxwell (and indeed it is largely through the lens of the history of laboratory physics that the belief that big science had no historical precedent was established). The big science of Victorian Britain has only a small place in the current historiography. And from within an account of big science in the nineteenth century, the entire landscape of scientific culture looks different. For example, from this angle the military emerges as the central institution of Victorian science. The Admiralty was especially influential on science in both cultural and financial terms. Currently however, military institutions are almost entirely absent from the historiography of Victorian science.

It was a sunny morning in Jamestown, St Helena, on 7 November 1677. Given its extreme remoteness – St Helena is a tip of volcanic land in the South Atlantic Ocean equidistant between South America and Africa – Jamestown was surprisingly urbane in the 1670s. For over a hundred years, the port had been a supply outpost of the British East India Company and, before that, was used by the Portuguese. Far south of the equator, usually cloudless, formerly uninhabited and now English-civilized, St Helena was a perfect place to observe the southern night sky. In November 1677 one aspiring astronomer, a well-off twenty-one-year-old Englishman named Edmond Halley, was here to map the southern stars and to observe a relatively rare transit of Mercury. That is what he was doing on the sunny morning of 7 November, at around 9 o'clock. Halley had his telescope (fitted with a smoked-glass filter) pointed at the sun. A small black notch appeared at the outer edge of the solar disc, creeping into the limb of the sun. The notch grew into a small black semicircle. It was the silhouette of the planet Mercury, cast onto the sun as seen from Earth. Halley watched with special interest as, at approximately 9.30, the shadow's entire shape, a circular silhouette, finally completed itself.

Government observatories of the nineteenth century were not generally important sites of experimentation and research. Experimentation was something more likely to be found – in Britain at least – in a private observatory or laboratory. But the case of the transit of Venus would be different. Although the general plan to be followed was 200 years old, and although the basic set-up would be the same as it had for the transit of 1769 a century earlier, the astronomers preparing for 1874 faced major unknowns. During the four years between the establishment of the programme and the day of the transit of Venus, preparations would consist largely of time-pressured research and experimentation into these unknowns. The highly-refined surveillance of celestial motions that defined Greenwich astronomy would be supplemented with speculative experimental investigations into subjects ranging from conductivity in telegraphic wires to the shape of the sun to the properties of photographic emulsions. Greenwich would come to look more like the private astrophysical observatories of men such as Norman Lockyer, and in the process Airy would enlist the help of some of the most prominent amateur astronomers.

The direction and scope of research was shaped by a number of issues, with the dominant concerns circling around the black drop phenomenon. In the early 1870s there also emerged new theories about the physical nature of the sun that bore directly on the black drop and other key issues, especially those relating to photography. Photography was just one of a whole new range of technologies available for making different sorts of approaches to the transit of Venus measurements, and by and large these technologies would have to be applied in new and untested ways. At almost every stage in the development of the programme there was virtually no clear agreement among the experts from different nations about the best way of proceeding.

While the programmes in France, Germany and the United States were organized around commissions, in Britain Airy was the sole manager. He described his management philosophy to Arthur Auwers at the Berlin observatory in 1873: The British arrangements for the transit of Venus do, in fact, rest with me.

Back in 1857, when Airy first described plans to observe the transits of Venus, he had proposed to devote most attention to the transit of 1882. The circumstances of the 1882 transit were more favourable for a few reasons: the transit duration was longer and thus its measure should have a smaller degree of error, and the entire transit would be visible from existing observatories throughout North America. The transit of 1882 should have brought an even larger effort by the astronomical community.

An article in the New York Times put a cynical and wildly inaccurate spin on the ‘great popular transit’, making the claim that astronomers in 1874 had purposely hidden the fact that there was to be a transit of Venus in 1882 (and that they also hid the fact that a ‘transit [sic – confused with Mars in ascension] of Mars’, which allegedly could just as well be used to measure the parallax, had been due in 1877).