Gavey's ring transformer, c 1892.
© Science Museum / Science & Society Picture Library
In the 1890s John Gavey was assistant to W H Preece, Engineer-in-Chief of the Post Office. Gavey designed this transformer for use with Preece's experiments in wireless telegraphy by means of the technologies of conduction and electromagnetic induction. It was acquired by the Science Museum from the former BT collection because of its significance as an artefact from radio research carried out in Britain before Marconi's arrival in 1895.