William Du Bois Duddell
William Du Bois Duddell (1872-1917), electrical engineer
1872 Born on 1 July at 23 Westmoreland Place, Kensington, London, the son Frances Kate Du Bois.
1881 his mother married George Duddell (d. 1887), a landowning gentleman of Queen's Park, Brighton.
Showed early mechanical aptitude
From 1890 to 1893 apprenticed to Davey, Paxman and Co of Colchester.
Studied at the Central Technical College (later the City and Guilds College), South Kensington; obtained a Whitworth exhibition in 1896, and a Whitworth scholarship in 1897.
c.1899 Developed Blondel's idea for observing alternating current waveforms into a fully-engineered oscillograph; the Cambridge Scientific Instrument Co manufactured many different models of these oscillographs up to WWII when the cathode-ray oscilloscope was developed.
Duddell was commissioned by the government to find out how to silence the carbon arc lamps then in widespread use for municipal lighting; as an offshoot of this work, he invented the Singing Arc, one of the first electronic musical instruments; also developed many other measuring instruments.
WWI Intensive work for the government is thought to have contributed to his early death.
1918 Obituary [1]
WILLIAM DU BOIS DUDDELL was born in 1873 and died on the 3rd November, 1917.
It is told of him "that when he was only four, years old, he was given a model mouse as a toy, and, not satisfied with its immobility, took the works from a small clock and fitted them unaided into the interior of the mouse, turning it into a successful automobile. From that time forward his nursery became a fairyland of automatic toys, all made by himself, and mostly grouped so that several separate toys went through their movements at once, all worked from a central source of power."
Owing to his delicate health, his people stayed for many years at Cannes, where he was educated at the College Stanislas. He never went to a big school. Until he was past the age of 20, his parents never knew if he would live beyond the current year. He never had, therefore, the chance of gaining the self-confidence which success in field sports gives to a boy, and which is such a valuable feature of the education of young Englishmen. He was always fascinated by a fine piece of mechanism, and from his earliest years was made responsible for all the clocks in the house.
When, later, he went to serve his apprenticeship with Messrs. Davey Paxman at Colchester, his landlady used to complain that all his friends came and left their clocks "on her doorstep." Afterwards he studied under the late Professor Ayrton and Professor Mather, and worked for many years at the Central Technical College He was always one of Ayrton's favourite students, and his success was one of the greatest delights that Professor Ayrton ever enjoyed. When he began work there, the problem of the delineation of the wave-forms of alternating currents was being studied at the laboratories, and Duddell at once became engrossed in the subject. I was working with him on the wave-forms of the alternate-current arc, and we were using a laborious point-by-point method of plotting the waves of current and potential difference. He had set his mind on the production of an instrument that would record the curves instantaneously, and at this problem he worked continuously. Duddell was attracted by the bifilar type of instrument which had previously been tried by Blondel. He made the first instrument at home in his workshop, using flat phosphor bronze strip for the vibrator, and brought it along to test; it gave promise of success, but the damping was ineffective, and he set to work to find a method of damping the motion of the strips which would enable the instrument to record a true curve. In the end Duddell made a separate channel for each strip, with walls of extraordinary thinness, the channels being filled with a viscous oil, and succeeded in obtaining critical damping, thus making the instrument a practical success. Next arose the problem of light, and a long time was spent in designing the most efficient system possible. It was characteristic of his thoroughness and patience that he was never satisfied until he had obtained the best results that he thought it possible to achieve in every detail of his apparatus, and his standard was a very high one. The first oscillograph was designed by eye, but it is remarkable that when the complete theory was worked out, the best dimensions possible differed very little from those which had been chosen by Duddell by that instinct which is the sure sign of scientific genius. When his instrument was complete in every detail he showed it to the Institution, and no one who saw that demonstration is likely to forget the occasion. It was the finest proof of his extraordinary powers that could be given, both as a designer of new instruments and as an expositor, for his exposition, in both its clearness and directness, charmed his audience so completely that Mr. Mordey, who opened the adjourned discussion, admitted that " his heart was fuller than his head " when he had moved the adjournment at the previous meeting. In 1901 he produced a classical paper on the " Resistance of the Electric Arc " which was presented to the Royal Society; this paper was the result of over two years' continuous research. During the work Duddell discovered the " singing arc." He was trying to pass a high-frequency current through the arc by using a condenser and inductance shunted across it, when he discovered that the arc itself, under these conditions, would produce oscillations. This part of the paper was developed later in another paper read before the Institution on "Rapid Variations of Current in the Direct-current Arc," also accompanied at the meeting by another brilliant demonstration, which ended with the playing of " God Save the Queen " on the arc by means of a specially arranged key-board. This phenomenon is the scientific foundation from which Poulsen subsequently developed his high-frequency arc generator, which is now being used on a large scale for producing the continuous oscillations employed in long-distance radio-telegraphy. Another feature of interest in his Royal Society paper was the use of a very high-frequency alternator. In order to measure the resistance of the arc with a current of so high a frequency that the alternations could not produce any sensible variations in its temperature, Duddell built an alternator giving 120,000 periods per second, a frequency much higher than had been attempted by any previous experimenter with a mechanically driven machine.
In 1905 he read a paper with Mr. J. E. Taylor on" Wireless Telegraph Measurements " which described a number of quantitative tests (made with an instrument which he himself had designed) on the variations of signal strength with varying heights of antennae and varying distances between them. In this subject he always showed the keenest interest, and he had in his own laboratory in Victoria-street a small antenna with which it was his delight to read signals from distant stations, of very long wave lengths. The antenna was of relatively small proportions, and the records which he obtained with it were a remarkable tribute to his experimental skill.
In 1907 he was elected a member of the Royal Society and in 1912 was awarded the Hughes Medal.
In 1911 he read a paper to the Physical Society on a vibration galvanometer, which displayed all that care and refinement in detail that was so characteristic of him. One of his most useful inventions was the Duddell thermo-ammeter. This instrument was a development of the Boys radio-micrometer, but was modified in its final form so as to provide a portable instrument which can be used for the measurement of the highest frequency currents with accuracy and certainty. He was also responsible for one of the best patterns of Einthoven galvanometer, and for a twisted-strip galvanometer of great sensitiveness. Duddell held many prominent positions in the scientific world. He was president of the Commission Internationale de Telegraphie Sans Fils and presided over the conference held in Brussels in 1914, being largely responsible for the preparation of the programme of work which was ultimately decided upon.
In 1907 he was President of the Rontgen Society and was a Vice-President of the Wireless Society of London. He occupied the office of President of the Institution for two years, from 1912 to 1914, succeeding Dr. Ferranti, and he did much to set on a proper working basis the new schemes and methods that had been inaugurated in the period of Ferranti's presidency. His election to the office of President was a recognition not merely of his eminence in his profession, but also of the enormous amount of energy he put into the routine work of the Institution. He acted for many years as Chairman of the Papers Committee, and displayed all those qualities of tact and sound judgment which are so necessary for the efficient conduct of the work of this Committee. The Chairmanship of the Papers Committee of the Institution is, perhaps, the most responsible position, next to that of President, that the Institution has to offer, for on the papers read before it depends more than anything else the success of the Institution's work. It is no exaggeration to say that the credit of the Institution rose appreciably during the time that Duddell was in charge. He did a great deal for the Library, in which he always took an untiring interest, he was responsible for the initiation of the Lending Library, and the Museum was a child of his own creation. He never lost a chance of acquiring an interesting specimen, and the members have to thank him for much in this direction. He gave a great deal of valuable help and advice in connection with the experimental equipment provided in the new building; his own skill and experience as a demonstrator were invaluable, and he placed them without stint at the service of his fellow members.
His second Presidential Address in November 1913 on "Pressure Rises" was, perhaps, his most notable achievement as an expositor: the experiments were all difficult and required great skill in their performance, but they were all successful, and his model of the oscillating arc was a triumph of the demonstrator's art. He had a great gift of clear exposition, he never read a paper or lecture, but talked about his experiments with such obvious interest and delight that he fascinated his audience and made them as enthusiastic as he was himself about what he was showing them. Another lecture which showed Duddell at his best was the one he gave to the British Association at Leicester, on the "Arc and the Spark in Radio-telegraphy." In the course of it he passed several amperes of high-frequency current through his body and some of those present afterwards remonstrated with him at the possible risk he ran in so doing He gave a course of Christmas Lectures for children on "Signalling" at the Royal Institution which delighted them by the ingenuity of the experiments and the unfailing skill with which they were shown. He also delivered Royal Institution discourses on "High Frequency Currents " and other subjects. He was a member of the Advisory Board to the Department of Scientific and Industrial Research, and of the Board of Inventions and Research of the Admiralty.
Duddell was no mean linguist, and those who have heard him conduct an International Conference will remember the wonderful skill he showed in reconciling the points of views of men of different nationalities It is an unspeakable grief to his friends that he has died so young, though few men have ever achieved so much in so short a time, but he worked himself to death; he was always in his office or laboratory and he hardly ever took a holiday. He has left behind him a record of which any man might be proud. Had he been gifted with strength of body at all comparable with his gifts of intellect, there is no limit to what he might have accomplished. Yet with all his brilliance he was so unassuming and kindly that all who met him became his friends He was an enthusiast for science, and a great man of science, but he was also one of the kindest natures that have ever lived. That he reached the highest possible positions in his profession was an evidence of his innate ability, and he will long be remembered as one of the best friends the Institution has ever had.
He joined the Institution as a Student in 1894, was elected an Associate in 1897, an Associate Member in 1901, and a Member in 1904. He served as a Member of Council from 1901 to 1908, as Vice-President from 1909 to ior2, and as President from 1912 to 1914. He also served as a trustee of the Benevolent Fund from 1914 until his death.