In 1924, foreign and Dutch newspapers reported about ‘deadly rays’. These and other mysterious rays would have been observed especially in Germany. [These messages were probably based on the hoax by the English researcher Harry Grindell Matthews].

It took until 1934 before the deadly ray discussion became news in the United Kingdom (see: Brian Johnson, The Secret War). 

As a result of these reports, questions were asked in a secret meeting of the Defence Commission of the House of Representatives to the Minister of War. Minister of War, Dr. J.J.C. van Dijk, however, had already been triggered by earlier reports from other information sources. His conclusions and preliminary decision can be found in Memorandum Minister of War Van Dijk, Secret Litt. P.42 of May 9, 1924:

As you will be aware, the literature and the press have already mentioned several times mysterious means of combat, involving e.g. use of wireless electrical waves and the like for destructive purposes.

Especially in recent times, numerous – usually fantastic – announcements of this nature have been made in newspaper reports from various origins, although further confirmation of the correctness of these reports has continued to fail.

A few months ago, a German party offered me some new means of combat, with the understanding that I was asked for financial support to further develop those inventions. I then made a proposal, which could have been accepted without objection by a bona fide party. However, I have not heard anything about this for several months, so I doubt whether this so-called inventors were in good faith.
The question also arises to what extent other such claimed inventions have any truth behind them. {…}

However, in my opinion, there is now a well-founded reason to suspect that in the near future, in addition to chemical weapons, physical weapons will also be used in warfare and will come to the fore, including completely new means of combat that have not yet been used, e.g. use is made of wireless electric waves, etc. for destructive purposes.” {…}

In the meantime, it seems to me that full attention should be paid to the possibility of the invention of physical means of combat as referred to here. I am therefore considering setting up a physical technical committee, which should devote its attention to these physical weapons, independently of the Committee on Chemical Weapons.  {…}

With regard to the last point [ref to ‘general mandate of a Commission for Physical Armament’], I note that the alleged inventions – or fantasies – in the field of physical means of combat, as far as I know, can be distinguished into:

  1. the targeted emission and concentration of X-rays (Hertzian waves) at great distances and thereby the generation of powerful electrical sparks between metal objects.
  2. the targeted emission of electromagnetic waves and thereby disabling the magnetos of explosion engines (has recently been mentioned in various newspapers and was presented to me as an invention on the above-mentioned occasion).
  3. the targeted emission of wireless electric waves for certain explosives at a specific frequency, in order to cause those explosives to detonate at a great distance (this was – among other things – at the beginning of the month of April mentioned in newspaper reports by the Hollandsch Nieuwsbureau. An English inventor MATH[I]EU GRINDELL is said to be capable of covering an area of 50 miles radius up to an altitude of 5 miles unsafe for anything explosive).
  4. the targeted emission of electrical force rays, which could wirelessly kill living beings at great distances (see – among others – the book by PH. OPPENHEIM; “Mr. Lavendale Diplomat”).
  5. the targeted transmission and concentration at great distances of high-frequency wireless electric power waves of different potential, whereby, with enormous heat development between the focal points of these rays, a “Siedeboog” would be created of exceptionally high electrical voltage which would affect all materials – e.g. also armour steel – would burn through in no time (was offered to me as an invention on the aforementioned occasion).

The Inspector of Engineers, No. 1368 Secret on June 13, 1924: {…} Also in my opinion, the to-be-established Commission for Physical Armaments should be composed of a Professor as chairperson, assisted by one or more assistants (at the discretion of the Professor); an officer of the General Staff; an artillery officer, and an engineer officer. Since the professor-chairman and his assistant(s) will of course fully master the physical part of the issues to be dealt with by the Commission, in my opinion, the military members of the Commission, in addition to their special military knowledge, should jointly be particularly competent in the field of engine and aircraft technology and explosives, all for military purposes.

Minister of War Van Dijk, Secret Litt. C.67, July 28, 1924: The Commission’s task will be to study the full extent of the problem of physical means of combat (including in particular the use of wireless electric or electromagnetic waves for destructive purposes) and to indicate in broad terms the direction in which possible solutions for each part of the problem should be sought by the physical and related sciences, in accordance with our conditions, and finally to advise me on matters related to those questions.
I asked Prof. Dr. KAMERLINGH ONNES in Leiden to accept the chairmanship of the Commission in question, but this Professor asked me to apologize to him, in view of his state of health and his age, for not being able to assume this chairmanship. 

Prof. Dr. Heike Kamerlingh Onnes recommended Prof. Jr. Dr. G.J. Elias (professor of Delft Technical University) in his place. After a discussion with him and the approval of the Minister of Education, Arts and Sciences, the Commission for Physical Combat Equipment was established by Ministerial Order of November 25, 1924 (Minister of War, Secret Litt. R.108). The earlier establishment of the Chemical Warfare Committee in 1923 served as an example of this.

Physical means of combat comprise various new means of combat, which are based on the special application of light, sound, heat or electricity. Some of these means of combat are known, and some are still a subject of study. This includes: devices for determining the position – based on sound or heat – of targets on earth, in the air or under water; electrically charged obstacles; the use of wireless electric waves for controlling motor-driven, unmanned means of transport, for detonating explosives, for destruction or destruction purposes, etc. Insofar as electrical equipment is used in the aforementioned means of combat, this naturally also involves wires for electrical conduction to fit.
Minister of War Van Dijk (21 February 1925) in: First Chamber 1924-1925 parliamentary document number 2 VIII subnumber 2, p 481