1860, The role of the popularizers in the Vulcan affair

By Hsiang-Fu Huang

Astronomers and historians often refer to the discovery of Neptune in 1846 as a triumph of Newtonian celestial mechanics. The irregularities of the orbit of Uranus led French mathematician Urbain Le Verrier  to correctly predict the location of a hitherto undiscovered planet. By discovering a planet at the tip of a pen, scientists showed feats of intelligence and caught the imagination of the public.

Another absorbing but often underrated episode in nineteenth-century science was the search for the hypothetical planet ‘Vulcan’ (not to be confused with the fictional homeworld of Mr. Spock in Star Trek!). Like Uranus, the anomalous orbit of Mercury, which was inconsistent with theory, had long troubled astronomers. To solve the mystery, Le Verrier claimed that an undiscovered planet – or at least a mass of asteroids – stood between Mercury and the Sun. For a brief time, astronomers thought they had found this hypothetical planet and officially named it ‘Vulcan’, after the Roman god of fire. The breaking news of Le Verrier’s triumph once again became a sensation.

Poster advertising C.H. Adams and His Orrery
A poster advertizing a Lenten astronomical lecture in April 1860 in London, three months after the discovery of Vulcan made for sensational news in France, shows how the discovery was adopted for a public lecture in a theatre in Britain. The poster encapsulates transits of knowledge across different boundaries: between countries, contexts, and media. 
The lecturer, Charles Henry Adams, was a schoolmaster and regularly delivered astronomical lectures with the transparent orrery in West End theatres during Lent. This kind of astronomical show was a phenomenon in nineteenth-century Britain. As a seasoned showman, Adams could not miss the Vulcan story and made the intramercurial planet a main feature in his lecture.

In hindsight, Vulcan is an error or an obsolete folly, like aether and epicycles. The planet does not exist. Le Verrier stuck up for Newtonian mechanics and hence created Vulcan, which was debunked by a later ‘better’ theory (Einstein’s general relativity).  The initial sensation and eventual failure of Vulcan reveals a complex network of knowledge production and circulation behind the historical scenes. Involved in the wider construction of the discovery were not only elite and amateur astronomers, but also journalists, writers and lecturers, such as C. H. Adams. They were crucial to construct the image of science in public, yet most of the time they are ignored in accounts of this episode.

James Secord urged historians of science in his ‘knowledge in transit’ to conceptualize the making of scientific knowledge as a form of communicative action. The phrase refers not only the circulation or transmission of knowledge, but also to the dynamics shaping knowledge – changes, compromises, or even mutations – as it is circulates. To adopt such a perspective helps historians to see that, as sociologists of science explain, truth is not the cause but a consequence of claims to knowledge being accepted. Social factors, such as effective networks of popularizers, often play a significant role in the process. The Vulcan affair is more than a conceptual shift from Newtonian mechanics to Einstein’s general relativity. It also reminds us the ‘invisible’ role of the popularizers.

Image creditsPoster advertising C.H. Adams and His Orrery at the Princess's Theatre, 1860 

Hsiang-Fu Huang is a postdoctoral research fellow at the Institute of Modern History, Academia Sinica.
He is also an honorary research associate at UCL Department of Science and Technology Studies, where he was awarded his PhD.
His research interests include the history of popular science, science in the long nineteenth century, and the representation of science in media and culture.

Email: hsiang-fu.huang.10@ucl.ac.uk