SEALED FARADAY DOCUMENT

Dominion, Volume 31, Issue 203, 25 May 1938, Page 3

SEALED FARADAY DOCUMENT

Opening After 100 Years

PIONEER DISCOVERIES

The recent opening of a sealed letter written by Michael Faraday in 1832 which had lain unopened in the safe of the Royal Society for more than 100 years has added a hitherto unrecognised chapter to the early history of electricity, says a writer in ‘‘The Times” (London).

At the time the document was written little but the most elementary of facts was known about electricity and magnetism. Electric lights, electric bells and telegraphs were unknown, and it ha'd only been discovered a few years previously that magnetism could be produced by electricity. Michael Faraday, who. from humble parentage had become Director of the Laboratory of the Royal Institution, argued conversely that it should be possible to produce electricity from magnetism. For nearly seven years his experiments were unsuccessful until at last, in the autumn of 1831, the reason for his failures became apparent. Then, in a series of brilliant, researches which were completed in a few days, he made the discoveries upon which the whole science of electricity an'd magnetism has developed. Discoveries Described. He described his discoveries in a paper read before the Royal Society on November 24, 1831. Among other experiments he told how he had found that a momentary pulse of electricity was induced in a wire by the starting or stopping of a current in an adjacent wire, and how a current of electricity was generated whenever a conductor was moved toward or away from a magnet. Certain of his results evidently led him to believe “that magnetic action is progressive . . . and requires time fo.- its transmission.” This was a revolutionary theory—tlie instinctive deduction of a brilliant experimentalist —ami though he had no definite., indication of its truth he was sufficiently sure of his theory to take the unusual course of depositing a sealed statement of his views with the secretary of the Royal Society. Tlie consent of the Council of the Royal Society to the custody,of tho scaled document is recorded in the minute book of the period, and on April 12. 1832. the packet was deposited in the society’s safe. There it remained until a short time ago, when it was decided that sufficient time had elapsed to open it, together with sundry other documents, none of which contained anything of interest.

Plain Statement.

The document is dated March 12, 1832, from the Royal Institution, and,

in the plainest of plain language, Faraday states: “ . lam inclined to compare the diffusion of magnetic forces to the vibrations upon the surface of disturbed water or those of air in the phenomena of sound —i.e., I am inclined to think the vibratory theory will apply to these phenomena as it does to sound and most probably to light. By analogy I think it may possibly apply to the phenomena of induction of electricity also.”

He goes on to explain the reasons for taking the unusual procedure of depositing this sealed document: “These views I wish to work out experimentally, but as . . . the experiments may in their course be subject to the observation of others, I wish, by depositing this paper in the care of the Royal Society, to take possession as it were of a certain date, and so have right, if they are confirmed by experiments, to claim credit for the views at that date, at which time so far as I know no one is conscious of or can claim them but myself.—M. Faraday. It was contrary to Faraday’s principles to patent any discovery. All that he demanded, and this insistently, was that he should receive the credit for discovery. There had been at least two incidents in earlier years, when his rights had been unjustly disputed. It is inconceivable that Faraday could have detected the almost inflnite- • lv short time required for the transmission of electro-magnetic phenomena with the primitive apparatus at his disposal. None will question, however, that he was the greatest experimentalist the science of electricity has ever known and the unerring manner m which his instinct led him to conceive the time-factor and the wave theory is little less than amazing. Maxwell’s Development. We know that it was Faraday’s experimental researches and his conception of the magnetic field as consisting of lines of force which formed the data upon which Clerk Maxwell developed his electro-magnetic theory. Maxwell proved mathematically in 1865 that electro-magnetic phenomena are propagated through space in the form of a wave motion with the velocity of light, but it has not been previously recognised that Faraday was the original author of the theory so early as 1832. The theory remained unconfirmed experimentally until 188 S, when Heinrich Hertz in a brilliant series of researches showed how to produce and detect electro-magnetic waves, and, in so doing laid the practical foundations upon which the whole art of wireless telegrphy and broadcasting has developed. ° The fact that Faraday expressed his belief that, time was required for the propagation of electro-magnetic forces and in their transmission by wave phenomena within such a brief period of his epoch-making discoveries of the relations between electricity and magnetism is of remarkable historic interest and is yet a further proof of his profound genius. But. though the credit for the original suggestion thus belongs to Faraday, to Maxwell remains the honour of confirming the identity between light and electro-magnetic radiation and of establishing the mathematical basis upon which the modern practice of wireless has developed.