2013 is the bicentenary of the birth of David Livingstone, British missionary and explorer who famously lost communication with the outside world during his 1866-1873 African expedition to find the source of the Nile. This resulted in the 1871 expedition of Henry Stanley to search for him (and the phrase ‘Dr Livingstone I presume?’ on their meeting entered folklore ). With the discovery of electromagnetic waves and developments in radio technology a modern day’ Livingstone’ has access to a range of aids for navigation and communication to keep him in touch with the outside world.

This symposium, sponsored by the Institution of Engineering and Technology (IET), aims to highlight how the application of scientific theories and discoveries has led to developments in radio technology which have changed the world, and exploration, since Livingstone's day.

This introductory paper considers some aspects of the origins of radio communications.

Many scientists contributed to the emergence of radio communications but the paper read to the Royal Society in 1864 by James Clerk Maxwell, predicting electromagnetic (EM) waves, is seen as a fundamental landmark. But for the failure by the Royal Society, in 1880, to recognise the accidental discovery of EM waves by David Hughes some 7 to 8 years before Hertz, the story of radio may have been different. However it was the experiments by Hertz using electrical discharge sparks to generate EM waves which are today seen as the confirmation, in 1888, of Maxwell’s predictions.

Interestingly Garrett, who has studied the private papers of Hertz, could find no evidence that Hertz saw any practical application of his discovery ? Oliver Lodge, in his 1894 memorial lectures for Hertz, has been credited by many as giving the first demonstration of the use of EM waves for wireless telegraphy. However this paper will consider the more recent arguments advanced by Sungook Hong that this is not so, and the true credit rightly goes to Marconi.

The use of a spark to generate EM waves, while adequate for telegraphy, was not well suited for voice transmission. Continuous waves(CW) were identified, by Fessenden among others, as necessary for that purpose. Practical cost effective means of generating and amplifying CW were not realised until the electronic era commenced in 1904 when Fleming in the UK invented the diode valve and, later, Lee de Forest in the USA inserted a grid creating the audion (triode).