Despite much excellent work over the years, the vast history of scientific filmmaking is still largely unknown. Historians of science have long been concerned with visual culture, communication and the public sphere on the one hand, and with expertise, knowledge production and experimental practice on the other. Scientists, we know, drew pictures, took photographs and made three-dimensional models. Rather like models, films could not be printed in journals until the digital era, and this limited their usefulness as evidence. But that did not stop researchers from making movies for projection at conferences as well as in lecture halls, museums and other public venues, not to mention for breaking down into individual frames for analysis. Historians of science are more likely to be found in the library, archive or museum than the darkened screening room, and much work is still needed to demonstrate the major effects of cinema on scientific knowledge. Film may have taken as long to change science as other areas of social life, but one can begin to glimpse important ways in which ‘image machines’ (cameras, projectors and the like) were beginning to mediate between backstage experimental work and more public demonstration even around 1900.

When it comes to knowledge about the scientific pasts that might have been – the so-called ‘counterfactual’ history of science – historians can either debate its possibility or get on with the job. Taking the latter course means re-engaging with some of the most general questions about science. It can also lead to fresh insights into why particular episodes unfolded as they did and not otherwise. Drawing on recent research into the controversy over Mendelism in the early twentieth century, this address reports and reflects on a novel teaching experiment conducted in order to find out what biology and its students might be like now had the controversy gone differently. The results suggest a number of new options: for the collection of evidence about the counterfactual scientific past, for the development of collaborations between historians of science and science educators, for the cultivation of more productive relationships between scientists and their forebears, and for heightened self-awareness about the curiously counterfactual business of being historical.

Science writer, historian and administrator J.G. Crowther (1899–1983) had an uneasy relationship with the BBC during the 1920s and 1930s, and was regarded with suspicion by the British security services because of his left politics. Nevertheless the Second World War saw him working for ‘establishment’ institutions. He was closely associated with the BBC's Overseas Service and employed by the British Council's Science Committee. Both organizations found Crowther useful because of his wide, international knowledge of science and scientists. Crowther's political views, and his international aspirations for the British Council's Science Committee, increasingly embroiled him in an institutional conflict with the Royal Society and with its president, Sir Henry Dale, who was also chairman of the British Council's Science Committee. The conflict centred on the management of international scientific relations, a matter close Crowther's heart, and to Dale's. Dale considered that the formal conduct of international scientific relations was the Royal Society's business rather than the British Council's. Crowther disagreed, and eventually resigned from the British Council Science Committee in 1946. The article expands knowledge of Crowther by drawing on archival documents to elucidate a side of his career that is only lightly touched on in his memoirs. It shows that ‘Crowther's war’ was also an institutional war between the Science Committee of the British Council and the Royal Society. Crowther's unhappy experience of interference by the Royal Society plausibly accounts for a retreat from his pre-war view that institutional science should plan and manage BBC science broadcasts.