This paper concerns the movement of the old navigational instrument, the compass, into the new situation of the aeroplane in the early part of the twentieth century. In order for the technology that had so long resided on ships or in the hand to continue to function in new contexts, a huge amount of work was required. Relationships were forged and made fraught, inventions were made to contest and succeed one another, new scientific and technical knowledge was produced. Throughout, the perceived nature of compasses and magnetic fields underwent subtle but significant shifts. Until recently histories dealing with the emergence of the aerocompass have largely black-boxed the technological changes, with only superficial treatment of issues lying beyond the compass itself.1 John Bradley's exploration of the feud between the Admiralty and military compass designers, and the sections in both Bradley's and A. E. Fanning's work on lawsuits over originality,2 go some way towards rectifying this imbalance. This paper extends that work further. It focuses on events in Britain, particularly those centred on two institutions, the Admiralty Compass Observatory at Ditton Park, Slough, and the Royal Aircraft Factory (later the Royal Aircraft Establishment) at Farnborough.

By the early twentieth century there was a growing need within palaeoanthropology and prehistoric archaeology to find a way of dating fossils and artefacts in order to know the age of specific specimens, but more importantly to establish an absolute chronology for human prehistory. The radiocarbon and potassium–argon dating methods revolutionized palaeoanthropology during the last half of the twentieth century. However, prior to the invention of these methods there were attempts to devise chemical means of dating fossil bone. Collaborations between Emile Rivière and Adolphe Carnot in the 1890s led to the development of the fluorine dating method, but it was not until the 1940s that this method was improved and widely implemented by Kenneth Oakley to resolve a number of problems in palaeoanthropology, including the Piltdown Man controversy. The invention of the fluorine dating method marked a significant advance in the quest for absolute dating in palaeoanthropology, but it also highlights interesting problems and issues relating to the ability of palaeoanthropologists and chemists to bring together different skills and bodies of knowledge in order successfully to develop and apply the fluorine dating method.