C. G. G. [C. G. Grey], 'A real aerial defence', Aeroplane, 12 June 1913, 670:
It has been brought to our attention -- it comes from the City, so it must be true -- that Britain has at last acquired a real means of enforcing the Aerial Navigation Act. It is alleged that a great inventor has persuaded the Secretary of State for War that he has an invention which, by means of Herzian [sic], or some similar waves -- vulgarly known as 'wireless' -- will cause the magneto ignition apparatus of all aircraft within a radius of seven miles to cease from functioning. In other words, the engines of all aircraft within range will be stopped, aeroplanes will be forced to land where they can, and dirigibles will be left at the mercy of the winds.
The account further states that the inventor has been allotted a piece of Government land in the neighbourhood of Folkestone, which is to be thoroughly surrounded by sentries to prevent foreign Powers who have neglected to provide themselves with City correspondents or copies of this journal from obtaining the slightest inkling of the fact that experiments are in progress.
This is a rather tongue-in-cheek account (if it's not clear from the quotation above, consider that Grey goes on to suggest that friendly aircraft be equipped with 'a clockwork or elastic drive' for backup -- and there's more where that came from), but it does sound like it derives from a real claim made by a City newspaper or newspaper correspondent, though it could just be a rumour current in financial circles. Even if Grey just made the whole story up, though, it's still a very early example of the idea of a death ray, at least in the sense, which became common from the 1920s, of an electromagnetic means of interfering with internal combustion engines at a distance. And it's in an air defence context, too. I know of no earlier such death rays, which of course means there are probably many.1
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