When it comes to crank death-ray schemes Great Britain wasn't about to leave the field to the American and the Italians, so they put their own Harry Grindell-Matthews (1880-1941) of the Welsh Looney Eleven in to bat.
Grindell-Matthews's 1924 death ray was a versatile little device as ultimate weapons go. It could blast aeroplanes out of the sky, explode gunpowder and cartridges, stop petrol engines in their tracks, shrivel plants, electrocute mice, light incandescent bulbs, and ignite oil lamps at a distance of up to four miles – not to mention being an excuse for dressing up in snappy overcoats and flying helmets for outdoor tests.
Grindell-Matthews's claims stirred a great deal of public interest to the point where His Majesty's government offered him £1000 to carry out further development. The inventor, however, avoided anyone taking a close look at his device and did a neat two-step; pleading an eye injury and claiming that he'd already sold the secret of the ray to the Americans. He then quietly vanished from public sight only to resurface at Hampstead Heath with a new ray.
It wrote "Happy Christmas" on the clouds.