This article is reprinted by kind permission of The Editor of The Royal Naval Scientific Service Journal. The most recent edition of this Journal contains an article by R.F. Pocock, A.M.S.E., giving a somewhat different slant to the Jackson story. This we hope to publish in the near future.

  Admiral of the Fleet Sir Henry Jackson held many appointments of national importance during his lifetime, but his fame may yet come to rest mainly on his early inspired work on wireless telegraphy, which he carried out aboard Defiance. But for the restrictions imposed on him by the naval life of those days Jackson might well have challenged Marconi in the invention of radio.

  The career of Henry Bradwardine Jackson was, in some respects, a paradox. The picture that one conjures of him from the literature of his time is of a shy, retiring and rather nervous man - an image that ill accords with that of a man who held most of the important Admiralty appointments at one time or another, and who attained the highest rank that the Royal Navy can offer. It is hardly too much to say that he achieved greatness unwillingly for it is certain that he cared little for the success d'estime that attended his position. What meant more to him that all these honours was his association with the development of radio from the earliest days. From 1895, when as Captain of the Defiance he demonstrated naval wireless communication for the first time, until his death in 1929 he held a unique position among the pioneers of the craft. It is true that the view held by the writer that Jackson invented wireless telegraphy is not generally accepted; but few would deny that his contribution to the science was of the greatest value. It is as 'Jackson of the Defiance' that he will be remembered and that is as he would wish.

Early Concepts

  Henry Jackson, a farmer's son, was born at Barnsley in 1855. He chose a naval career although his family had no strong connection with the sea and he joined the Service just before his 14th birthday. With his Daealian mind it is not surprising that he asked to be allowed to qualify in the torpedo branch, which was then the only branch of the Navy that afforded opportunity for scientific research. At first his career followed a normal pattern and it was not until 1890 when he was appointed to Vernon that it becomes of unusual interest.

  A task which then confronted Vernon was that of designing a device by which friendly torpedo boats might give warning of their approach to their parent ship. The possibility of using the newly discovered Hertzian waves immediately occurred to Jackson; they were then regarded merely as a scientific curiosity - a practical demonstration of Maxwell's theory - and no useful application of them was known or nvisaged. Since, however, at that time no means of readily detecting the presence of these waves was known, Jackson was forced to put the problem on one side and it was not for five years that he was able to make any progress.

The First Transmission of Signals

  In 1895 he had read of the work on coherer detectors by Sir Jagadis Bose and at once saw the old problem now capable of solution. By now he was in command of the torpedo training ship Defiance at Devonport and it was on board this ship that his experiments were carried out. They culminated one day in August when he succeeded in sending Morse signals from one end of the ship to the other.

  The apparatus used by Jackson was naturally of a primitive nature. After detection by a cohere which Jackson made himself, the received signal operated a relay which in turn actuated an electric bell. The ringing of the bell without the agency of any external wiring heralded a new epoch - the radio age.

  The reports of the Defiance experiment seems to have been lost on the Admiralty who appear to have made no attempt to patent Jackson's method.

Meeting with Marconi

  The anti-climax caused by this somewhat lukewarm reaction left Jackson undismayed. He continued his experiments and in 1896 - newly promoted Captain - he received signals over a distance of several hundred yards by the use of a larger spark and a more efficient coherer. By this time, after much advance publicity, Marconi arrived in England and was introduced to Jackson at a conference at the War Office. This oddly contrasted pair, the young Italian with all the flamboyance of his race and the taciturn Englishman, had in common a great belief in the futur of their invention. Though regarded as rivals (as in a sense they were) this bond was the basis of a friendship which lasted until Jackson's death. Each had previously been unaware of the other's work; now most secrets were shared and neither ever abused the trust placed in the other. Jackson was now able to persuade the Admiralty that further experiments would be of value; they authorised him to continue them and allocated some money for the purpose. He was, unfortunately, unable to fully avail himself of this opportunity since he was appointed in the following year as Naval Attache in Paris, where such research was almost impossible.

Naval Restriction

  Whether or not Jackson would have seriously challenged Marconi in this field will never be known. The Italian had several advantages; he was untrammelled by the restrictions imposed by a Service career and had a small band of trained assistants to help him. Marconi and Jackson were popularly regarded as competitors in a sort of race to produce a workable wireless-telegraphy system. But in truth, if we are to pursue this analogy, Jackson was clearly a non-starter. In Paris he could do nothing except give advice to his successor in Defiance (Captain Hamilton) who was continuing the experiments in a rather desultory fashion and with little success. Jackson's loyalty and devotion to duty were unquestioned but, even so, his chagrin at being taken from his work in Defiance could not be altogether concealed.

  "I was naturally very disappointed.", he wrote to Marconi, "at having to leave off my experiments when they were in a very interesting stage and at a time when probably my personal supervision was most required as, at the time, everyone seemed against the system except you and I."

  Typically, however, he was able to refer to this, one of the greatest disappointments of his life, as "one of the little things one has to put up with in our Service."

  "Accept my congratulations on your recent successes", he wrote, "which have evidently surpassed those of any other experimenters on the subject, including myself".

Conversion of the Admiralty

  Jackson cared not at all that the prestige and honour which so easily might have been his, would now devolve on Marconi; his one concern was that the Navy should enjoy the advantages of wireless as soon as possible. Accordingly he devoted his energies to trying to persuade the Admiralty that Marconi's equipment was worth a trial. The Admiralty, however, put forward a number of objections to this proposal one of which was a report by the Signal Committee "against the use of wireless for fear that it would blow up the ship's magazine". This observation was not altogether unreasonable at a time when little was known about the new invention, but it was unfortunate in that it further increased the unwillingness of the Admiralty to try the equipment.

  That in 1899 the Admiralty at last changed their minds was due almost entirely to Jackson's persistence; they agreed to let Marconi fit his equipment in four ships for the manoeuvres of that year. Jackson was home by now and in command of Juno which - he made sure - was one of the four ships selected for the trials. The trials were astonishingly successful, ranges of 60-70 miles were regularly obtained and the commander of the victorious force, Admiral Domville, attributed his success largely to the use of wireless which he said, with obvious wonderment, "was equally efficient in all weathers".

  The doubts which the Admiralty had entertained were now removed and a contract was placed with the Marconi Company for 32 sets. Indeed so enthusiastically did the Admiralty now take up wireless telegraphy that we find Jackson of all people, complaining in a letter to Marconi "that it was being done so hurriedly that we suffer from a want of skilled operators".

A Clash fo Opinions

  Under Jackson's guidance the development of the naval wireless service now proceeded rapidly although at first the Admiralty were very reluctant to pay the royalty of ??100 per installation which was asked by the Marconi Company.

  Indeed expert advice was sought to determine whether an action to dispute the validity of the Marconi patents would be likely to succeed. Sir Oliver Lodge was asked for his opinion and in his report he pointed out that on 1st June, 1894, a year before the Defiance demonstration - he had performed a very similar experiment. He implicitly accused Jackson and Marconi of copying his work, a charge that Jackson refuted with unusual heat.

  "At the time I first commenced my experiment in 1895 I had not heard of Lodge's experiments and I had not read any of his works nor any of those mentioned by him and though I have since studied some of them and have learnt there from much of the phenomena connected with wireless telegraphy, I certainly have not learnt anything of any practical use from any of them".

  With no less vigour Jackson defended his erstwhile rival Marconi from the charge of plagiarism. Describing Lodge's report as "extremely egotistical and biased" he pointed out that Marconi had begun his work in an Italian village where "Dr. Lodge's work and name were less well known than he thinks possible".

  Jackson was convinced that Marconi was fully entitled to profit by his invention and it was partly as a result of his attitude that the Admiralty came to a mutually satisfactory arrangement with the Marconi Company.

  This controversy is of interest in that it seems to be the only occasion on which Jackson took part in the dispute over priorities. The fact that Lodge's experiment took place a year before Jackson's does not, the present writer belives, deprive Jackson of the place as the father of wireless telegraphy. Lodge's case is spoiled by his admission that he "did not pursue the matter into telegraphic applications as he was unaware that there would be any demand for this kind of telegraphy". Because Jackson did immediately see just such a demand and as Marconi's first successful transmission did not take place until December, 1895, Jackson's precedence would seem to be indisputable.

Development Work

  Jackson, who was from 1899 generally responsible for wireless development in the Navy, delighted in his new work, From the torpedo depot ship Vulcan, of which he was in command on the Mediterranean station, he reported frequently and enthusiastically both to the Admiralty and to Marconi. His researches were directed mainly to extracting the greatest possible efficiency from the equipment by careful tuning. He also carried out an exhaustive study of the screening effect of land and of the interference caused by atmospherics, which he embodied in his famous paper read to the Royal Society in 1902 to which he had been elected in the previous year.

  In the years leading to the First World War, Jackson's reputation steadily increased. From 1905 to 1908 he served as Third Sea Lord and during this appointment he was promoted to Flag rank and was knighted. His appointment as Commander of the Sixth Cruiser Squadron in the Mediterranean was followed by a two-year term in charge of the newly-created Royal Naval War College.

First Sea Lord

  The outbreak of war in August 1914, marked the beginning of a new phase in Jackson's career. He held a succession of appointment at the Admiralty which brought him from comparative obscurity to the scrutiny of the public gaze. When in the following year, the First Sea Lord, Lord Fisher, resigned in somewhat sensational circumstances, Jackson succeeded him. The appointment was everywhere well received. It was a time of the gravest anxiety: losses due to submarine warfare increased week by week and it was widely felt that Jackson with his scientific background and even temperament was well suited to fill this key post. It is sad to record that these hopes were ill-founded.

  The U-boat campaign claimed more and more victims and Jackson's rooted objection to the convoy system must have been at least a contributory factor to this state of affairs. Dissatisfaction in the country at the way in which the war at sea was being waged found expression in the correspondence columns of The Times and was brought to a peak when that most influential newspaper strongly criticised Jackson's direction in a leading article.

  The Prime Minister, Mr. Asquith, could no longer ignore the clamour of public opinion and pressure from within the Cabinet, and so Jackson was swept from the public scene by a wave that engulfed not only him but the First Lord and feeling is evident from the obviously sincere letter of good wishes which he wrote to Jellicoe, his successor. Possibly he was not sorry to relinquish an office for which he was temperamentally unsuited.

  One event in this somewhat unhappy episode of Jackson's career gave him great satisfaction. He revealed after the War that the Royal Navy was able to engage the German fleet at the battle of Jutland because of information received from naval direction-finding stations. They reported that a change in bearing of signals intercepted from some of the German ships indicated the fleet had left their moorings at Wilhelmshaven and were moving down the Jade River to the sea. This forewarning proved of the greatest vaue to the Royal Navy, which was thereby able to meet the enemy in favourable waters. Nothing could have vindicated Jackson's belief in the value of wireless more than this.

The Last Years

  Jackson retired to the more peaceful scene of the Royal Naval College, Greenwich, where he remained as President until his promotion to Admiral of the Fleet in 1919.

  In 1920 he was appointed First Chairman of the Radio Research Board of the Department of Scientific and Industrial Research and under his supervision research of the greatest importance was carried out for which he, characteristically, disclaimed all credit. He was a familiar and well-loved figure at meetings and conventions and did much useful experimental work at his home mainly in the field of short-wave propagation. An event that took place about this time, which gave him much pleasure, was the award in 1926 of the Hughes medal of the Royal Society.

  In 1929 he moved to Saltern's House, Hayling Island, and on the 14th December of that year he died at the age of 74. His grave may be seen in St. Mary's Churchyard, South Hayling.

  In the thirty-five years that have passed since Jackson's death the science of radio has made strides so great that we are perhaps inclined to overlook the remarkable achievements of the pioneers of the craft who persevered in the face of prejudice and opposition.

Acknowledgements

  My thanks are due to Marconi's Wireless Telegraph Co. for allowing me access to correspondence in the Company's archives; to the staff at the Admiralty Library and to Mr. McLoughlin of the A.S.R.E. Library, for their cheerful and invaluable assistance.