In the second half of the nineteenth century, gas discharge research was transformed from a playful and fragmented field into a new branch of physical science and technology. From the 1850s onwards, several technical innovations – powerful high-voltage supplies, the enhancement of glass-blowing skills, or the introduction of mercury air-pumps – allowed for a major extension of experimental practices and expansion of the phenomenological field. Gas discharge tubes served as containers in which resources from various disciplinary contexts could be brought together; along with the experimental apparatus built around them the tubes developed into increasingly complex interfaces mediating between the human senses and the micro-world. The focus of the following paper will be on the physicist and chemist Johann Wilhelm Hittorf (1824–1914), his educational background and his attempts to understand gaseous conduction as a process of interaction between electrical energy and matter. Hittorf started a long-term project in gas discharge research in the early 1860s. In his research he tried to combine a morphological exploration of gas discharge phenomena – aiming at the experimental production of a coherent phenomenological manifold – with the definition and precise measurements of physical properties.

By the turn of the twentieth century a distinct ‘social domain’ – along with its constituent parts, problems and internal dynamics – was turned into a political entity, and a concern for state bureaucracies existed across the industrializing world. Specific motivations for this trend may have varied from location to location, but included arguments for higher industrial productivity and less political discontent, often intertwined with a humanitarian impulse in calls for better housing, expanded public health or improved working conditions. As has been well documented, the politicization of the social domain in early twentieth-century Britain owes much to the consolidation of British sociology as a distinct discipline. Yet while the link between the rise of social politics and sociology has been established with regard to Britain, little has been said about the occurrence of this coupling elsewhere in the twentieth-century British Empire. This article aims to rectify that omission by showing the interplay between newly raised social concerns of the colonial administration in the Bombay Presidency, Western British India, and the establishing of sociological research within the borders of the Presidency around the time of the First World War. The article will explore how the colonial administration in Bombay planned to meet new demands for sociological knowledge in colonial state policy, how sociology was subsequently introduced into the Presidency as a research subject, and how new sociological methods were applied in actual colonial government.

In the last years of the eighteenth century, Egypt famously witnessed the practice of European sciences as embodied in the members of Bonaparte's Commission des sciences et des arts and the newly founded Institut d'Egypte. Less well known are the activities of local eighteenth-century Cairene religious scholars and military elites who were both patrons and practitioners of scientific expertise and producers of hundreds upon hundreds of manuscripts. Through the writings of the French naturalist Etienne Geoffroy Saint-Hilaire (1772–1844) and those of the Cairene scholar and chronicler ʿAbd al-Raḥmān al-Jabartī (1753–1825), I explore Egypt as a site for the practice of the sciences in the late eighteenth century, the palatial urban houses which the French made home to the Institut d'Egypte and their role before the French invasion, and the conception of the relationship between the sciences and social politics that each man sought. Ultimately, I argue that Geoffroy's struggle to create scientific neutrality in the midst of intensely tumultuous political realities came to a surprising head with his fixation on Paris as the site for the practice of natural history, while al-Jabartī’s embrace of this entanglement of knowledge and power led to a vision of scientific expertise that was specifically located in his Cairene society, but which – as Geoffroy himself demonstrated – could be readily adapted almost anywhere.

The unconventional correspondence between physicists Albert Einstein and Felix Ehrenhaft, especially at the height of the alleged production by the latter of magnetic monopoles, is examined in the following paper. Almost unknown by the general public, it is sometimes witty, yet it can be pathetic, and certainly bewildering. At one point the arguments they exchanged became a poetic duel between Einstein and Ehrenhaft's wife. Ignored by conventional Einstein biographies, this episode took place during the initial years of the Second World War, but was rooted in disputes dating back to the early years of the twentieth century. The interesting intersection of a series of scientific controversies also highlights some aspects of the personal dramas involved, and after so many years the whole affair in itself is still intriguing.

This article presents evidence that an anonymous publication of 1573, a Letter sent by a gentleman of England [concerning …] the myraculous starre nowe shyning, was written by Thomas Digges, England's first Copernican. It tells the story of how it arose out of research commissioned by Elizabeth I's privy counsellors in response to the conventional argument of Jean Gosselin, librarian to Henri III of France, that the star was a comet which presaged wars. The text is significant because it seems to contain the observations and opinions that Digges held before he completed his other astronomical treatise, the groundbreaking Alae seu scalae mathematicae. It also casts some light on the development of Digges's radical and puritan views about the star, Copernican astronomy, the infinity of the universe and a belief that the ‘latter days’ of the world had arrived.

This essay analyses the circulation of political models and administrative practices drawn from the Enlightenment statecraft of metropolitan Portugal and their inscription in specific colonial contexts of Angola in the mid-eighteenth century. The purpose here is to show how these models had to be ‘unpacked’ when confronted with foreign contexts, reconfigured and even reinvented for local circumstances. During the 1750s, the Lisbon government conceived a new imperial project to territorialize the colony through the intellectual and physical appropriation of this Central African space. In order to do so, three levels of this administrative knowledge are distinguished: the quantification and systematization of information, cartography, and the archive. For each, this essay demonstrates how they were made available to, appropriated by or transformed by both the colonial and the African societies in the colonial context.