It began with a strange photograph posted on the internet which claimed to show trials of a death ray machine being conducted on Flat Holm island. The island is located 1.5 mile off the coast of Cardiff and is the southernmost point in Wales. The border between Wales and England crosses the island at its most southerly point .At low tide a corner of the island lies in England but at high tide the sea consumes the English border and the island for brief periods remains completely Welsh.
There are many legends and stories related to the island but one of the most perplexing concerns the photograph which purports to be an image of trials of a death ray conducted on the island in 1925 by an inventor named Harry Grindell Mathews.
During the 1920’s he became well known as an inventor. In 1923 he claimed to have invented a death ray which could destroy or stop engines from functioning by aiming an invisible ray at them. Matthews claimed to have conducted tests which had stopped a motorcycle engine and ignited gunpowder from some distance. These tests were conducted in the presence of journalists who published excited reports of the incidents. Matthews refused to explain how his machine worked.
In 1924 he demonstrated his ray gun to armed forces officials by switching on a light bulb and cutting off a motor. The officials suspected he was tricking them but they were sufficiently concerned to grant an injunction to stop him selling the rights to the death ray to others. However, Matthews fled to Paris and despite repeated requests from the Air Ministry he refused to give any further proof.
Strangely, in June 1924 , he returned to the United Kingdom and offered to conduct a demonstration which was then filmed. This was a Pathé news reel called The Death Ray which can be seen on https://www.youtube.com/watch?v=qbNgvHfK4wI. The film shot in a laboratory, shows a light bulb being switched on whist being held by two assistants and with no visible connection. The second shows gunpowder being ignited from a distance. The message in the film, highlights its use in the future as having the potential to destroy a town. As Tim Romano notes the director of the film was Gaston Quiribet whose background was in special effects, possibly an odd choice for a science documentary.
In 1934, Matthews returned to the United Kingdom and moved to a village in West Wales , Betws. Here he built a complex Tor Clawdd for his experiments. After a talk about the island I had just given, a gentleman from the audience who had been raised in Betws , remembered his father talking about the reclusive inventor who lived at Tor Clawdd. His father told him about seeing strange lights coming from the laboratory at all hours and mysterious planes flying in and out of the land near the property.
Harry Grindell Matthews was not the only person working on death rays at the time. Another contemporary inventor was Nicola Teslar who has received much greater attention.
It is very difficult to state for certain the photograph was taken on Flat Holm, but its isolated location would have been an ideal place to conduct such experiments.
http://news.bbc.co.uk/1/hi/wales/south_west/8262548.stm article about Matthews’s links with Wales.
https://www.thevintagenews.com/2017/07/25/the-disputed-death-ray-of-1923-and-the-other-inventions-of-harry-grindell-matthews/ the background to many of Matthews’ inventions.
https://www.youtube.com/watch?v=qbNgvHfK4wI The news reel showing a demonstration of the death ray
http://flatholmsociety.org.uk/ for a full background to the island.
Gillham, Mary E Memories of Welsh Islands Dinefwr Publishers (2004)
Jory, Bob Flat Holm- Bristol Channel Island Wincanton Press (1995)