About Leonard Fuller
Leonard Fuller graduated from Cornell University around 1912. Upon graduation, he was employed by the National Electric Signaling Company. He then took a position with the Federal Telegraph Company, where he eventually was named Chief Electrical Engineer. During the 1920s, he worked for General Electric Co. on carrier-current communications, subsequently returning to Federal as Executive Vice President and Chief Engineer. In 1930, he joined the University of California, Berkeley faculty as Chair of the Electrical Engineering department.
The interview begins with Fuller's remarks about his early interest in wireless, and his visit to the Poulsen Wireless Company's wireless stations while a student at Cornell. He then discusses his work on high-powered arcs for the Poulsen Company, which later became the Federal Telegraph Company. He mentions the Naval demonstration tests done in 1912 with continuous wave signals. The interview continues with a discussion of Fuller's carrier current communications work, for both Federal Telegraph and General Electric during the 1920s. The interview concludes with a discussion of his acquaintance with Ernest Lawrence and his unique contribution to Lawrence's cyclotron.
About the Interview
LEONARD FULLER: An Interview Conducted by George T. Royden, IEEE History Center, May 29, 1976
Interview # 031 for the IEEE History Center, The Institute of Electrical and Electronics Engineers, Inc.
Request for permission to quote for publication should be addressed to the IEEE History Center Oral History Program, 39 Union Street, New Brunswick, NJ 08901-8538 USA. It should include identification of the specific passages to be quoted, anticipated use of the passages, and identification of the user.
It is recommended that this oral history be cited as follows:
Leonard Fuller, an oral history conducted in 1976 by George T. Royden, IEEE History Center, New Brunswick, NJ, USA.
INTERVIEW: Leonard Fuller INTERVIEWER: George T. Royden DATE: May 29, 1976
Early Interest in Radio
This is George Royden interviewing Dr. Leonard Fuller, on May 29, 1976, on behalf of the History Committee of the IEEE. Dr. Fuller, would you mind telling how you came into the radio field, and anything else that you think might be of historical interest?
I shall be glad to do so, George, but first I might say that for some time I have been recording that story at great length for the History of Science Project of the University of California Bancroft Library. That project is now in its third year, and the recordings that I have given them are now being transcribed into their final form. I think probably by September of 1976 this material will be available in the History of Science division of the Bancroft Library at the University of California at Berkeley. That material will consist of about 225 type-written pages of bound in book form, and would give a much more detailed answer to your question than I can give you at this time. It occurs to me also that anyone interested in this historical material might find it helpful to refer to Who’s Who in America, American Men of Science, and works such as Who’s Who in the West and Who’s Who in Engineering. Any issue in the years 1930, 1940, or 1950 should give this material. At present, I am now in the "Who Was Who" category, and I think the material would be found there.
Now, for a specific answer to your question. As a boy I was always interested in mechanical and electrical affairs. At one time I was a member of a neighborhood telegraph line and became interested in telegraphy and in due course in wireless. I think my first interest in wireless came when the newspapers reported some of Marconi’s early work, particularly trans-Atlantic communication, which I believe was in about 1902. In 1905, I began to listen in with a little electrolytic detector that I was able to build out of an old incandescent lamp [by] cutting off the glass and using the two platinum lead-in wires through the glass press as the electrodes to the electrolytic detector. In any event, my first memory of hearing a wireless telegraph signal was with that detector. By 1906 I had a spark transmitter and was fortunate enough to have a very good source of high voltage, in that I was able to obtain a loan from the local power company of a 33,000 volt oil insulated potential transformer, which made an ideal transformer for my spark transmitter. My condensers for that transmitter were made out of the proverbial glass bottle, salt water, electrolyte design, and I had a very good antenna because we had a tall fir tree not far from the house in Portland, Oregon where I lived, so the antenna was strung to the top of that tree.
Cornell and Poulsen Wireless (Federal Telegraph Company)
I went to Cornell after graduating from Portland Academy in 1908. Some of my parents' friends had been approached by the Poulsen Wireless Telephone and Telegraph Company of San Francisco, to buy some stock in the company. During my summer vacation of 1940, these friends of my parents, knowing of my interest in wireless telegraphy, suggested that I might like to go to San Francisco and see the Poulsen wireless stations. This I did, in about August 1910, visiting the early stations at Sacramento and Stockton and at the beach station south of the cliff house on the ocean shore in San Francisco. While at Cornell I became quite active in the Cornell radio station. Upon graduation I was employed by the Fessenden Company, the National Electric Signaling company at Bush Terminal in Brooklyn, New York. In due course, this company ran into financial difficulties, like so many wireless telegraph companies, and at that time I applied for a position with the Poulsen company in San Francisco. By this time the name of the company was Federal Telegraph Company.
I applied to Cyril F. Elwell, who was Chief Engineer and an organizer of the company, whom I had met in my visit in the summer of 1910. My first assignment had to do with the development of the Poulsen arc. The company had at that time not only the station at the beach, but also one at South San Francisco for communication with the station in the Hawaiian Islands. These stations were equipped with thirty kilowatt arcs, and it was found that although they had satisfactory night communication, they did not have a commercial quality signal for daylight work. Accordingly, the company wished to develop a higher-powered arc for that purpose. Up to this time, the company had developed arcs up to thirty kilowatts, from the original Danish design of around five to twelve kilowatts, by, as it were, viewing the dimensions of the smaller arc under the magnifying glass and deciding what the dimensions of the larger arc should be by that method. That proved fairly satisfactory up to thirty kilowatts, but not above that. The result was that when the company built what they hoped would be a sixty kilowatt arc, it turned out to be a thirty kilowatt arc with larger dimensions. It was obvious that something was not understood in the design of arcs. So without going into detail at this time, let me say that that was my original assignment, and that was my main duty for a number of years.
Cyril Elwell left the company in 1913, and in due course I was made Chief Electrical Engineer of the company, in charge of all engineering and manufacturing operations. The company had a small factory in the downtown section of Palo Alto, but as our arc power developed and we installed a 100 kilowatt arc at the Panama Canal zone for the Navy, it became apparent that with additional Navy orders coming along for still larger sizes, a new factory would be necessary. This was, in due course, built and in about 1916. It had a railroad sighting coming in from the Southern Pacific tracks and gave us ample space for manufacturing and laboratory facilities. Arcs ranging in sizes from 200, 350, 500 and up to 1,000 kilowatts of capacity were developed and built at that plant.
I recall Cyril Elwell telling me of the tests he made at Annapolis on behalf of the Navy. Could you elaborate on that?
I think you may be referring to the tests in the winter of 1912- 1913, from the Arlington Station to the cruiser USS Salem. These were historical tests in many ways. They demonstrated so clearly and for the first time the advantages of continuous waves over damped waves. In December 1912, Cyril Elwell took a thirty kilowatt arc, a duplicate of the type we were using at the South San Francisco station, and installed it at the new naval station at Arlington, Virginia. That station had just installed a 100 kilowatt Fessenden 500 cycle synchronous rotary-gap transmitter, using compressed-air condensers. This transmitter had previously been tested for some time from the Fessenden station, the National Electric Signaling Company station, at Brant Rock, Massachusetts. The receiving station was in Maprahannish, Scotland.
The Fessenden transmitter at Arlington was having its acceptance trials, and immediately following those, the Poulsen arc, installed by the Federal Company, was installed. Arrangements were made by the Navy whereby the cruiser Salem was equipped with all of the latest types of receiving equipment for both spark and continuous waves. A considerable personnel of technical talent from both the Navy and the National Electric Signaling Company, was aboard the Salem. Arlington sent scheduled tests day and night, and the Salem sailed from the Delaware River eastward across the Atlantic, recording alternately from the arc and from the spark transmitter. Signal strengths were measured by the shunted telephone method, and signals were judged for quality for telegraph reception by ear. After about 1200 miles, 1200 to 1500 miles out, it became apparent that the arc was beginning to be superior to the spark, and the arc received signals during daylight in Gibraltar. One of the receivers on the Salem was a beat-frequency reception type of receiver. Now, this was before the days of the oscillating vacuum tube, so that the local oscillator for beat reception was a small laboratory arc without magnetic field, about the size one could hold in one's hand.
These tests were doubly interesting to me, because when I was with the National Electric Signaling Company at Bush Terminal, I was assigned, along with Robert B. Wolverton, who later became Radio Inspector in San Francisco and retired as a Colonel in the Signal Corps of the United States Army, to the assignment of developing these little arcs for beat-frequency reception. Reginald Fessenden had been the inventor of the heterodyne type of reception, and the National Electric Signaling Company held patents on that. So when the Salem began to receive the arc signals, it first used a tikker aboard the Salem, and then also, concurrently, listened in with the beat frequency reception with the little arcs. It was quite apparent that the beat-frequency reception with the CW was quite superior to beat-frequency reception with the spark transmitter, for obvious reasons.
Commercial Telegraph By Radio
I recall Cyril Elwell telling me that the Federal Telegraph Company was organized to enter the commercial telegraph business and bring in some money for the company. Could you tell us a little bit more about that phase of the Federal operations?
The first Federal arc stations were built at Sacramento and Stockton, California for demonstration purposes in early 1910. A little later, the station I mentioned earlier, at the beach of San Francisco, was constructed for demonstration purposes also. As time passed, it was felt that the time had come when the company might undertake a commercial channel. A station was built in Los Angeles, and the first commercial circuit of the Federal Company was between San Francisco and Los Angeles. This circuit was very successful and handled a heavy traffic in both press and commercial business. As time passed, stations were also built for communication with Portland and Seattle via a relay station at Central Point in Southern Oregon. In due course, stations were also built at South San Francisco and Honolulu for the Hawaiian circuit. The Pacific coast chain and the Honolulu circuit were very successful, and I think there is no doubt that they were the most successful venture in handling commercial telegraph traffic by radio that was developed anywhere in the United States.
Carrier Current Problems, Hoover Dam, and GE
I recall that you did some of the early work with carrier-current on high voltage electric transmission lines. Would you mind telling us, Dr. Fuller, of some of that work?
In the early 1920s, the Great Western Power Company of San Francisco completed two hydroelectric generating stations on the Feather River, providing power for the San Francisco area. The Feather River lines were, at that time, the longest and the highest voltage lines in the world. John Koontz, Chief Engineer of the Great Western Power Company, approached me with the question, of whether I could help the company improve communication between the dispatcher’s office in Oakland, California and the power plants on the Feather River. The company had its own wire telephone lines, but in winter storms communication of that sort was unreliable. His thoughts were along the lines of radio telephony or telegraphy. But after looking into the matter, I decided that it was probably a better approach to attempt to transmit the telephony over the power lines as a carrier-current operation. Accordingly, I designed three transmitters for this purpose, and Mr. Ralph Heintz of the firm Heintz and Kaufman in San Francisco built them in his shops to my design. These were installed on the Feather River lines, and because of their satisfactory operation, the Pacific Gas and Electric Company approached me to see whether I would attempt to install carrier-current transmitters on their new 220,000 volt Pitt River lines. These stations were installed, and operated for some years. Subsequently they were changed to single sideband transmitters supplied by the Bell system. One interesting factor connected with the Pitt River lines was the fact that the copper conductors on these lines were a rope lay rather than a smooth surface cable lay. The result was more corona loss on these lines than had been anticipated, and a corresponding interference with any carrier-current communication or radio in that vicinity of those lines.
That carrier-current on high voltage transmission lines is very interesting; and as I remember, it became quite important for the power companies. I seem to recall that you went east to help the General Electric Company. Can you tell us more about it?
After the Pacific Gas and Electric company pioneer carrier-current installations were in operation, I was approached by the General Electric Company and offered a position at Schenectady, New York in carrier-current work. I went to Schenectady, and in the course of my work there was asked to visit most of the power companies in the United States that had high voltage transmission lines and communication problems that might warrant carrier-current consideration. This involved a study of these systems and an analysis of their problems. I found this particularly rewarding work.
Some time later, when the Hoover Dam to Los Angeles power lines were installed, I was asked to study the carrier-current problems on those lines. By this time, carrier-current involved not only voice communication, but telemetering, remote control of switches, and information transmission of that sort. The Boulder Dam lines were equipped with all of these methods of communication, so the load dispatcher in Los Angeles was able not only to communicate by voice, but to receive constant telemetering signals from various locations on the system, indicating load, voltage, and so on. Also, remote control of switches had distant points, such as switching stations out in the desert, and signal back from the switches showing the operation was accomplished with carrier-current. This was probably the most elaborate type of carrier-current use on power lines that was developed. Later on, of course, microwaves and communications of other sorts came into use.
Federal Telegraph Company and Berkeley
Would you mind telling us of the developments when you returned to the Federal Telegraph Company in Palo Alto?
After working for General Electric at Schenectady for some time, I found myself in the San Francisco office of General Electric, looking after carrier-current communication for the power lines on the Pacific coast and west of the Rocky Mountains. At about this time, the Federal Telegraph Company again approached me. They offered me a position of Executive Vice President and Chief Engineer with duties which involved general management of the plant at Palo Alto, which was faced with the new problems of manufacturing vacuum tubes and developing short-wave transmitters for radio stations.
This work continued until the Depression of the 1929-1930 period caused the IT&T to consolidate manufacturing operations in one location, in Newark, New Jersey. This involved, among other things, the movement of the Federal Telegraph manufacturing operation from Palo Alto to Newark. This was accomplished over a period of time and by mid-1931 was fairly well completed. In 1930, the University of California offered me a position of Chair of the Electrical Engineering department, at Berkeley. I was able to make arrangements with Federal Telegraph and the University of California, whereby I devoted half-time to each operation as the Federal Telegraph company move to Newark was completed. This was finally completed in 1932 and from that time on I devoted full time to my academic duties at Berkeley.
Castings from WWI Transmitter and Cyclotron
During the First World War, the Navy ordered a large 1,000 kilowatt transmitter for installation in the United States, and that contract was canceled at the end of the war. But the castings remained at Palo Alto for a while. Would you mind telling what became of those castings?
I joined the University of California faculty in 1930, and soon became well acquainted with Ernest Lawrence, the inventor of the cyclotron. We used to meet at lunch at the Faculty Club almost daily, and I well recall one day when Ernest was quite elated and told me that he had found that he was able to make his cyclotron, built with a little four-inch diameter magnet pole, operate satisfactorily. It proved that the cyclotron principle he had envisaged would actually function. We discussed ways and means for him to obtain a larger cyclotron: the problem was, of course, one of finance, largely. I told him that at the Federal Factory at Palo Alto, we had a magnetic circuit made up of a number of pieces which fitted together, which would give him a magnet pole forty inches in diameter. That would be ten times the size of the cyclotron he had built for his laboratory work. I asked him if he thought this would be helpful; if so, I would see whether I might arrange for this to be given to the University of California as a gift. He said he thought it would be helpful, and accordingly I was happy to be able to arrange for this gift to the University of California. We had a winding machine, a bull lathe in the shop at Palo Alto, which had been used to wind the magnet coils for the 1,000 kilowatt arcs. These were composed of a copper strip about a quarter of an inch thick by an inch and a quarter wide. I suggested that the same type of flat pancake, ribbon-wound coil might be useful for the cyclotron. In due course we wound those coils also for the University. This provided the first cyclotron of large size in the radiation laboratory at Berkeley.
After Dr. Lawrence was able to finance a larger cyclotron, that cyclotron was sent down to the University of California at Los Angeles. My nephew, Dr. Herbert Royden, did his thesis work on that cyclotron. Eventually, that cyclotron was sent back to Berkeley and is now a memorial at the Lawrence Radiation Laboratory.
Dr. Fuller, you have had a very interesting experience, and I am pleased to have this interview that we can send to the IEEE Headquarters. If there is more information wanted, the detailed history that has been deposited with the Bancroft Library at the University of California at Berkeley may be consulted. I understand that this will eventually be available in book form. Thank you very much.
It’s been my pleasure, George.