Abstract :
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.