«NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA BIOGRAPHICAL MEMOIRS VOLUME XXI—FOURTH MEMOIS BIOGRAPHICAL MEMOIR OF ELIHU THOMSON ...»
NATIONAL ACADEMY OF SCIENCES
OF THE UNITED STATES OF AMERICA
VOLUME XXI—FOURTH MEMOIS
KARL T. COMPTON
PRESENTED TO THE ACADEMY AT THE AUTUMN MEETING, 1939
ELIHU THOMSON1853-1937 BY KARL T. COMPTON For one destined to apply his genius largely toward harnessing electricity for the work and comfort of man, the decade beginning with 1850 was a timely period in which to be born. The preceding half century had witnessed the fundamental discoveries which underlie the utilization of electricity, and imaginative minds had begun to direct these discoveries into the broad channels of practical and commercial employment.
In the development of the electrical art this first half of the Nineteenth Century was a remarkable fifty years, and because it provided the foundation for the practical achievements which came in the second half, a review of it helps to give perspective to this memoir on Elihu Thomson.
The century opened auspiciously with Volta's discovery of the voltaic cell, and with the demonstration by Nicholson and Carlisle of electrolysis. In 1820 Oersted announced his discovery that an electric current has the power to deflect a magnetic needle.
In this same year Ampere brilliantly elucidated Oersted's discovery by giving mathematical expression to the forces produced by electric currents. Six years later Ohm announced the formulation of his law that current is proportional to the electromotive force, and twenty years later Gauss and Weber invented an acceptable system of electrical and magnetic units.
Meanwhile, Faraday had begun the epocal researches which were to lay the foundations of electrical engineering. In 1821 he had succeeded in making a wire revolve about a magnet and a magnet about a wire, and ten years later, almost simultaneously with Henry in America, he made the great discovery underlying almost all electrical machinery—electromagnetic induction. This led him to the mechanical production of a steady electric current by revolving a copper disc between the poles of a magnet. Here, at last, in embryo, was the machine which ultimately would generate in one year in the United States alone 120 billion kilowatt hours of electric power.
NATIONAL ACADEMY BIOGRAPHICAL MEMOIRS—VOL. XXIMinds with a practical bent were quick to follow the road which Faraday and Henry had pointed out, but they found the going slow. By 1850, the electric motor had been demonstrated, the commutator had been devised, the electric arc had been experimentally used for lighting, and efforts had been made to drive boats, buggies, and locomotives by electricity. But the conquest of electric power was still thwarted by practical difficulties ; only in the form of the telegraph and a few other devices had electricity been put to work effectively. Efforts to obtain a reliable mechanical source of electric power languished.
It was during this stage in the development of the electrical art that Elihu Thomson was born in 1853, and it was not until he had embarked upon his professional career at the tender age of 17 and was ready to join the creative thrust that the drive toward economic utilization of electric power had really begun to gain ground rapidly. In 1875, five years after Gramme had built his ring-wound armature, and along with Siemens had made the dynamo a practical machine, Thomson had built a dynamo and by 1879 he had invented and patented a three-coil arc dynamo— the first three phase generator. He thus early took prominent place in the brilliant group, including Brush, Edison, Siemens, Stanley, Tesla, Van Depoele, Weston, and others, which was to solve the problem of generating adequate current. The electrical tide was approaching its flood and Thomson was ready— with consequences enormously important to the development of the electrical industry.
The young man who thus auspiciously began his career in Philadelphia was born in Manchester, England, on March 29, 1853, of a Scotch father, Daniel, and an English mother, Mary Rhodes. Elihu was the second son of the family which ultimately was to total eleven children, six boys and five girls. Four years after Elihu's birth, the panic of 1857 struck England and his parents, moved by the resulting scarcity of work, decided to emigrate to America, which they did in 1858, settling in Philadelphia. Elihu early showed signs of exceptional ability. When his parents felt the appropriate time had arrived for them to teach him his alphabet, they were astonished to discover that the
ELIHU THOMSON COMPTONyoungster, now five years old, not only knew the letters but could recite the alphabet both forwards and backwards.
Elihu's father was a gifted mechanician and his work led naturally to Elihu's interest in technical and industrial arts.
As he himself has recalled, "A great many of the industrial establishments, on account of my father's work as engineer and machinist, were open to me.
I was thus able to witness as a boy many of the industrial processes going on, both in chemical work and also in mechanical constructions, in which I was always interested even from the start. The literature which was available to me at home was chiefly the 'Imperial Journal of Arts, Sciences and Engineering', of which there were two volumes, which I studied actively.
Evidently my tastes had already been formed and were, perhaps, to a certain degree, hereditary, intensified by my father's occupation and that of several of my uncles, who followed mechanical pursuits. I was constantly endeavoring to imitate, in a small way, the processes and operations which I saw going on around me. Thus, at about the age of ten or eleven, I constructed small models of cupola furnaces with fan blowers for furnishing the blast and actually succeeded in melting cast iron, hoping to be able to get enough iron to make castings. In this, I was not successful, as the iron melted was not in sufficient quantity to run into a mold. I was, however, always interested in what was going on around me, such as the laying of water pipes and gas pipes in the streets, the building of sewers, etc., spending hours in watching the operations. I remember that I was constantly imitating on a small scale, or by drawings, operations mostly of an engineering nature which I saw going on about me. What I couldn't actually make, I contented myself by drawing. During the latter part of the period of the Civil War, I often visited the Philadelphia Navy Yard and operated a donkeyengine during the noon hour, so that the men need not stop work. This engine was used for the boring out of the propeller holes of two ships then under construction in the yard. One was an iron-clad cruiser called 'The Tonawanda' belted with four inches of iron on a wooden hull, and the other was a high powered ship intended for chasing blockade runners and named 'The Chattanooga'. As a boy of about fourteen years of age, I had access to a large chemical works, where sulphuric, nitric and hydrochloric acid were made, and where paints and pigments were a
NATIONAL ACADEMY BIOGRAPHICAL MEMOIRS VOL. XXIlarge portion of the production. Needless to say, I understood the processes from my own chemical reading." 1 Elihu entered the public schools of Philadelphia at the age of six and by the time he was eleven years of age, he was ready to enter the Boys' Central High School. Under existing regulations, he could not be accepted until he was thirteen, and because Elihu was not particularly strong, his parents seriously considered the recommendation of the grammar school principal that he give up studying entirely for two years and attempt to build up his physique. To this suggestion Elihu reacted promptly and violently, telling his parents that he would as soon die as to give up his books. The parents capitulated, and young Thomson embarked on a period of reading and a program of gadget making and youthful experimentation. He built a static machine from a wine bottle, small condensers, Leyden jars, a pair of telegraph instruments, and voltaic cells, and he assembled a collection of chemicals adequate to carry out many processes and reactions.
In February, 1866, he was finally admitted to the Central High School, even though he lacked several weeks of having attained the required age. Four years later he was graduated as fourth honor man and accepted employment in a commercial laboratory where analyses were made of iron ore and other minerals. He remained in this post for about six months and then returned to Central High School in the fall as "Adjunct to the Department of Chemistry" at a salary of $500 per year.2 One of the senior professors whom he assisted in this post was Edwin J. Houston, who held the chair of Physical Geography and Natural Philosophy, and the two were soon engaged in collaborative investigations which led to a long partnership. The first publication growing out of their research was a paper "On a New Connection for the Induction Coil," contributed by Professor Houston to the June, 1871, issue of the Journal of the From an unpublished letter, dated January 26, 1933, in the files of the National Academy of Sciences.
The Philadelphia Period in the Life of Professor Elihu Thomson by John Louis Haney. The Barnwcll Bulletin of Central High School, February, 1939.
ELIHU THOMSON COMPTONFranklin Institute. The paper contained an account of Thomson's observations of sparks drawn from grounded waterpipes during the operation of a nearby induction coil. Although he did not recognize the significance of the evidence at the time, he had clearly observed the propagation of electrical waves through space. When, in 1875, Edison announced a new "etheric" force which he described as non-electrical, Professor Thomson was primed to dispute his conclusions, for he wrote later "I had proposed to Houston that we carry on these experiments and show definitely that the so-called 'etheric' force that Edison had announced in the papers was merely an electrical phenomenon. At this time I took upon myself the enlargement of the scale of the experiments, so as actually to obtain a very definite result. This was carried out, as follows, in 1875. A 6-inch spark Ruhmkorff coil was set up with one terminal connected by a wire about 5 feet long to a large tin vessel mounted on a glass jar on the lecture table. When the coil was in operation, sparks were allowed to jump across the terminals of the coil itself, these sparks being about iy2 inches to 2 inches long and having the character of condenser sparks. When the coil was in action, I explored the whole building throughout the several floors and then went up to the top of the building to the observatory, where Professor Snyder had charge of the astronomical instruments. It was found that tiny sparks could be obtained from metal objects wherever they were, in the cases or outside, from the door-knobs or from apparatus, by the simple expedient of shading from the light and detecting the tiny sparks with a pointed pencil by applying it, say, to the door-knob. I recognized clearly that this was a manifestation of electric waves passed through space, and I also understood that a system of communication might readily be based thereon." 3 A description of this experiment was communicated to the Franklin Institute by Professor Houston and printed in its Journal for January, 1876. With the exception of Joseph Henry's experiments, which were unpublished, here was the first experimental demonstration of the validity of Maxwell's theory, and here, too, was an example of Professor Thomson's extraordinary intuition anticipating the wireless transmission of signals over a decade before Hertz demonstrated electroUnpublished notes of Professor Thomson in the files of J. A. McManus, General Electric Company, Lynn, Mass.
NATIONAL ACADEMY BIOGRAPHICAL MEMOIRS VOL. XXImagnetic waves and twenty odd years before Marconi received his patent on "telegraphy without wires".
Again in Thomson's nineteenth year, the Journal of the Franklin Institute, August, 1871, carried an account, written jointly by Thomson and Houston of further original work by Thomson.
This paper, "On the Change of Color Produced in Certain Chemical Compounds by Heat," was a pioneer discussion of this phenomenon. His next important paper, "On the Inhalation of Nitrous Oxide, Nitrogen, Hydrogen, and other Gases and Gaseous Mixtures" appeared in the Philadelphia Medical Times, November 15, 1873, and foreshadowed his later work on the use of helium in diving and caisson work.
By 1877 Thomson was swinging into his full stride. He had received the Master of Arts degree from his institution and been appointed Professor of Chemistry and Mechanics. His capacity to work productively in a variety of fields had been amply demonstrated by creative work in both chemistry and physics, and by such avocational activities as lens grinding and the construction of a pipe organ with electropneumatic key action. He had, during a series of successful lectures at the Franklin Institute, anticipated the system of electric-welding he was later to patent, he had conceived the idea of a cream separator, and he had described the operation of tuning one electrical circuit to another.
Thomson regarded his "more serious interest in electrical applications" * as beginning in 1878 with a series of tests on dynamos then in commercial use. This report had been preceded in the Journal of the Franklin Institute by papers on the relaying of the telephone and on "A New System of Electric Lighting and a New Form of Electric Lamp," and it was followed in 1879 by "Circumstances Influencing the Efficiency of Dynamo Electric Machines" published jointly with Professor Houston in the Proceedings of the American Philosophical Society. This paper, as did the report to the Franklin Institute, emphasized the advantage of low internal resistance in a dynamo as compared to the resistance of the external circuit.
"Pioneer Investigations on Dynamo Machines Fifty Years Ago," by Elihu Thomson. The Journal of the Franklin Institute, July, 1928.