In July 1900, at a scenic spot near Brighton known as Devil's Dyke, an enormous megaphone sent a human voice hurtling across the South Downs.
In an era before electronic amplification or radio, this new invention fascinated and terrified local people.
Its ability to project sound over miles and miles verged on the mythical.
The newspapers labelled it The Howling Terror and prophesised that its diabolical broadcasts would dominate the forthcoming twentieth century.
And yet today the Howling Terror is forgotten.
Alan Dein resurrects its strange story.