The recurrent denial of indigenous agency and ambition in schemes of European explorations strongly suggests the need to overcome the myth of western solitary travellers by taking a new and multi-perspective look at the inner life of expeditions. This paper analyses significant facets of the programme launched by the three Schlagintweit brothers in and beyond the East India Company (EIC) realm in South Asia. Their enterprise is significant not least for the vast quantity of materials and documents it accumulated and the ambiguous relationship it maintained throughout with its main sponsor, the EIC, and other agents and patrons of imperial and European sciences. The mission offers rich opportunities for the historical examination of major themes in the study of imperial knowledge, changing scientific practices and of transnational and cross-cultural engagement. Against the existing literature, I squarely place the Schlagintweit expeditions into their colonial context by exploring how their ambitious survey programme of physical geography, climatology, soil science and ethnography depended heavily on the mobilisation of the colonial infrastructure of British India, including its technical services, prisons, hospitals and imperial knowledge networks. The paper closes by analysing how the German travellers sought to both acknowledge the vital role of indigenous participation and instruction in their enterprise in published accounts, and the brothers’ simultaneous attempt to maintain their own authority as supposed ‘leaders’ in front of European audiences by portraying their South Asian companions as reliable and calibrated but ultimately inferior ‘instruments’ in the execution of their large-scale mission.

The scientific idea(l)s of racial anthropometry—as formulated by one of the most influential scientists of that field, Rudolf Martin, and taken over by his Dutch pupil Van der Sande—entailed a strict objectification of the study of anatomical difference in relation to geographical descent. It was, in the terms of Daston and Galison, a science driven by an epistemic ideal of objectivity through ‘selfless’ science, in which ‘first impressions’ or non-standardized measures and observations were anathema. Thus, when presenting the anthropometric data from his 1903 expedition to Dutch New Guinea, Van der Sande sought to completely disentangle his data from the story of the expedition. The data was presented as ‘pure facts’, ready for circulation in European ‘centers of calculation’. To un-tell this kind of scientific reporting, in this paper I will retrace the practicalities of the expedition. This will show how, in paradoxical contrast to an ideal of measuring race independent from subjective impressions, the expedition itself continuously enacted race in the way it assigned roles and practically divided groups within the expeditionary group. This contradiction short-circuited when the successor of Van der Sande in the third expedition, Von Römer, started to measure the non-European members of the expedition team.

In 1928, the Berlin Geographical Society launched an investigation into whether Hermann Detzner (1882–1970), a former colonial surveyor, had misrepresented his New Guinean expedition in his book, Vier Jahre unter Kannibalen (1920). The investigation stretched on for four years and drew in a who’s who of New Guinean research and politics at the time from Germany, Australia, and the United States. The investigators’ task was made all the more difficult because Detzner wrote his expedition reports from memory after Australian soldiers had destroyed his fieldnotes during World War I. In 1932, Hermann Detzner eventually admitted that his book was ‘a factual scientific report only in part’ and contained an ‘alternative depiction of […] facts’—in large part to protect the identity of those who shielded him from Australian troops. Consequently, historians today typically dismiss Detzner as an amusing anecdote—yet another August Engelhardt, consumed with coconuts and sun. Drawing on the investigation notes and other original archival sources, this paper seeks instead to recuperate the Detzner affair as a serious object of study for historians of science for two reasons. Firstly, the loss of Detzner’s notes brings into even sharper focus—for us, as for the investigators at the time—the status of notebooks as witnessing devices within the field sciences. And secondly, Detzner’s calculated efforts to disseminate genuine ‘facts’ within a fictional telling of his expeditionary activities raises interesting questions about the role of context in justifying the validity of scientific data.