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ABSTRACT

AWA Review Professor David EdwardHughes

2009 Ivor Hughes

In the earlier part of the1800’s, electricitywas a novelty - a scientific orphan. Then sud-denly, (in historic terms), all that changed. Anumber of clever experimenters observed thatelectricity could actually travel vast distancesinstantaneously along wires, and sought to putthis phenomenon to good use. When these pio-neers cracked open Pandora’s box, they hadno idea that it would lead to such a diverseand all encompassing communications indus-try that we all rely on today. The technologiesthat we now take for granted, can be tracedback to the pioneering work of the industriousVictorian scientists.

One of these was Professor David EdwardHughes. Hughes was a brilliant inventor andpractical experimenter as well as a gifted mu-sician, ever inquisitive and a true lover of sci-ence. He was born when Michael Faraday andJoseph Henry were still uncovering the mys-teries of “electricity”, a time when they andothers were wrestling with the observationsthat electricity could create magnetism, andmagnetism could be used to create electricity.He lived through a period rich in famous namesthat are still familiar today, such as WilliamThomson (Lord Kelvin), Cyrus Field, SamuelMorse, Thomas Edison and Alexander GrahamBell.

Hughes was to leave his mark through hisinventions and discoveries in the fields of te-legraphy, telephony, wireless, metal detection,and audiology. He was an international sci-entist whose life was spent between America,Britain, and Continental Europe, and becameone of the most decorated scientists, receivinghigh honors from no less than nine countries.Hughes was one of the few self-made scien-tists who were able to amass a substantial sumof money over their lifetime, which upon hisdeath he generously donated to the LondonHospitals. However, like many of the early sci-entific foot soldiers that laid down the founda-

Our society and tech-nology is built on the pio-neering work of the Vic-torian scientists. Unfor-tunately, with the pas-sage of time, only thepopular names are re-membered. If we peelaway this top layerthough, we can discovera host of scientists thatnot only made importantdiscoveries but also ledfascinating lives. One ofthese scientists was Pro-fessor David EdwardHughes FRS. His print-ing type telegraph instru-ment invented and usedin America was also in-strumental in the growthand success of the com-munications network ofEurope. His work onsuppression of electricalinterference and discov-ery of the carbon micro-phone led to improvedtelephone communica-tions and experimentswith his induction bal-ance led to the metal de-tector. His wireless ex-periments, for which hehad invented a uniquedetector enabling him toreceive a transmissionover distance of 500yards with his mobile re-ceiver in 1879-1880, area tribute to his ingenu-ity.

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tions of our communications in-dustry his name has tended to sinkbelow the history horizon. (Fig. 1)

family retired from the entertain-ment business to take up touringfor pleasure. Their travels wereextensive, covering NorthAmerica from Nova Scotia toNew Orleans. Any thoughts ofreturning to the old country ap-pear to have slipped away.

During this period of adven-ture, Hughes’ father became inter-ested in geology and mineralogy.Probably like so many of the earlypioneers, he dreamt of striking itrich and succumbed to “gold fe-ver”. Virginia was then the goldhot spot and this is where the fam-ily settled down, buying a farmthere in the 1840 s. Here they setabout farming and mining for theelusive ore. 2

During their travels, thechildren’s education was not ne-glected and a private tutor trav-eled with them. David Hughesshowed the same flare for the sci-ences as he had for music. He wasboth inquisitive and inventive andhis father built a laboratory nextto the farm. Here, Hughes spenthis time carrying out chemistryexperiments, taking mechanismsapart, building new ones, andmaking improvements to theirmining equipment. Hughes wasliving in an interesting time thatwould see the birth of many newtechnologies throughout his life-time. One of these was the tran-sition of electricity from a poorlyunderstood phenomenon into atechnological powerhouse. Thisoccurred when it was applied to theelectric telegraph introduced dur-ing the 1840’s by WilliamFothergill Cooke and CharlesWheatstone in England andSamuel F.B. Morse and Alfred Vailin America. Overnight, almost, itseems that communication timeshrank from months, weeks ordays to a matter of minutes.

Fig. 1. Prof. David Edward Hughes

David Hughes according to histomb inscription was born in 1830.His father, originally from Wales,and a boot maker by trade, was agifted musician who moved toLondon, married and had fourchildren. David Hughes and histwo brothers and sister appearedto have inherited their father’s giftand also turned out to be naturalmusicians.1 This talent wasn’twasted, as an infant musicaltroupe was formed and toured themusic halls of London and theprovinces. They were billed as the“Child Prodigies” and went on toperform for the Royal Family andother notables. (Fig. 2). Buoyedby their success, the child prodi-gies musical show was taken ontour to America, which opened itsarms to the child performers.Their popularity and novelty led tothe honor of performing at theWhite House. After several yearsof show business they had ac-quired significant wealth and the

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THE TELEGRAPH ERA

It was while Hughes was ateenager that he first saw a Morsetelegraph system in operation.Always inquisitive when he sawnew mechanisms, he questionedthe operator as to how it worked.Whilst simple and practical in itsoperation, it must have set his in-novative mind to ponder how sucha system could be improved. Overthe following few years, he was tobring his ideas to fruition by in-venting his own telegraph instru-ment.

As Hughes came to the end ofhis teen years, he became restlessand tired of the limited amenities

of rural Virginian farm life. Peoplewere starting to look to the westfor new opportunities and he de-cided to join the migration. Heapplied, and was accepted for apost as a professor of philosophyand music at a college in Ken-tucky. This was somewhat of anaccomplishment at his young agebut Hughes was proud of becom-ing a professor, a title he main-tained throughout his life. Themove to Kentucky in 1850 turnedout to be a tough period for himas he had limited money and hadto juggle his time to accommodateteaching, taking on private musicstudents and experimenting withhis ideas for a new telegraph in-strument.3

Fig. 2. The “Child Prodigees”

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During this period, Hughesstarted to formulate how he couldimplement the telegraph instru-ment he had in his mind. He de-cided that instead of using codesthat required operator training aswell as requiring multiple pulsesto be transmitted, it would be bet-ter if one could just type in themessage directly as alphabeticalcharacters and print them out atthe receiving station. Hughes wasnot alone in attempting to inventa better telegraph instrument anda number of systems had or wereappearing, using a variety of op-erating principles and vying fortheir place either in the Europeanor the American market. Theseused a variety of signaling meth-ods such as a multitude of shortand long pulses as in the Morsesystem, or a long stream of pulsesas in the step by step systems, orsignals of different polarity as inthe needle or dial systems.

In America, at the time therewere only two serious competitorsto the Morse system, theAlexander Bain electrochemicaltelegraph and the Royal EarlHouse printing instrument pat-ented in 1846 and in operation by1847.4 Whilst these instrumentswere used by some of the tele-graph companies, Morse was byfar the dominant system and theyconstantly fought to keep it thatway by challenging any attemptsby patentees of other systems.Hughes’s idea of typing in lettersand either displaying or printingthem at the receiver was not new,and had been used by PaulGustave Froment in France andRoyal Earl House in America.5

However, his ideas and approachwould result in an instrument thatwould both look and operate dif-ferently.

Hughes is renowned for buy-ing old clocks, dismantling them

and carrying out experiments withthe parts. Somewhere in this ex-perimentation, his ideas started togel as to how he could implementa printing telegraph. His conceptwas to provide a keyboard so thatthe letters could be typed in di-rectly, and at the receiving endprint out the letters and wordsonto a paper tape. (Sounds famil-iar and taken for granted today).One of the most ingenious partsof his telegraph, though, was inits method of transmitting the in-formation from transmitter to re-ceiver. Up to that time, telegraphsystems were based on transmit-ting voltage pulses and used onlythree parameters: amplitude, po-larity and duration in theirmethod of signaling.

Hughes introduced a time ele-ment to his scheme. His notes in-dicate he conceived of a one wavesystem, (waves were often used torefer to pulses).6 He had figuredout how to transmit all 26 lettersof the alphabet using a singlepulse. To accomplish this he con-structed a keyboard not unlike amanual typewriter, except thekeys were arranged in alphabeti-cal order. Next, he constructed amechanical scanning device thatcould scan the keyboard to deter-mine when a key had beenpressed. This was implemented byusing a rotating cylinder that hada helical pattern of 26 protrudingpins (not unlike a musical boxcylinder), and driven by a clock-work mechanism. (Fig 3).

When a letter key was presseddown, it pushed forward a contactthat was struck by a pin of thehelix on the rotating cylinder. Byconnecting a battery across thecylinder and keys, a voltage pulsewould be generated whenever acontact was made. The cylinderwas rotated at a constant speed inwhich time it scanned all 26 let-

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ters once each revolution.7 Forexample if the “A” key was pressedthe first pin on the rotating cylin-der would make contact and if “E”was pressed then the fifth pin wasstruck (but displaced in time by 5/26 of a revolution). Thus, he hadset up a repetitive time base (equalto the rotation of the cylinder)that was in turn subdivided into26 time slices. Each time slicecould transmit a one or a zero rep-resented by a pulse or no pulse.(In actual practice, Hughes used28 keys and ran at 120 rpm). De-pending at what position the pulseoccurred within the time base in-dicated which letter had been

transmitted. What he had con-ceived of was a pulse positionmodulation system that wouldfind many future applications andwould later evolve into time divi-sion multiplexing. (Fig. 4.)

At the receiver, he arranged fora print wheel (with 26 letters plusthe two extra positions - a periodand a blank) to rotate at a con-stant speed and in phase with thescanning cylinder in the transmit-ter. Below the print wheel was aplaten that could be rapidly raisedagainst it. A continuous paperstrip was fed over the platen.When a pulse was received, it trig-gered the platen to be rapidly lifted

Fig. 3. Helix Scan

Fig. 4. Pulse Position Modulation

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and briefly contact the print wheeland print a letter on the paper tape.Other mechanisms advanced thepaper and inked the print wheel.(Fig. 5).

Hughes’ challenge was how toget two telegraph instruments torun in perfect synchronism andphase separated by tens or hun-dreds of miles. Here all his experi-menting with clocks came intoplay. They were at the time themost precise mechanism avail-able. He solved the problem byusing a vibrating spring strip toprovide the precision timing in-stead of a pendulum, which wouldhave proved far too slow. The os-cillating spring strip drove a typi-cal clock mechanism of an anchorand escapement wheel. The powerfor the mechanisms was providedby a falling weight drive similarto that used in grandfather clocks.In return, the vibrating spring re-ceived a nudge from the escape-ment wheel each period to keep itoscillating. The vibrating springwas also fitted with a temperature

compensating mechanism tokeep the vibrating frequency con-stant.

Hughes took an approach tothe electrical signaling that re-quired minimum power. Thiswas in contrast to other telegraphssuch as the Morse instruments.For these, hefty batteries wereneeded, as all the power to drivethe receiver register relay had tobe supplied from the transmittingend (although later a local relaywas introduced to reconstituteweak signals).

Hughes’s approach was basedon transmitting lower voltagepulses and using a sensitive detec-tor in the receiver. The detectorwas a smart piece of design.Hughes used a permanent horse-shoe magnet with soft iron polepieces onto which were woundcoils. He then arranged an arma-ture to close across the gap, heldby the force of the magnet. Thearmature had a spring attachedthat could be tensioned such thatit was just about to pull the arma-

Fig. 5. Hughes’ original telegraph instrument

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ture clear. When a pulse was re-ceived, it was routed through thecoils. The resulting magnetic fieldgenerated was in opposition tothat of the permanent magnetthus weakening it. This caused thearmature to release and to fly offunder the influence of thetensioned spring. Not only did thisneed a lot less electrical power tooperate but also the response ofthe detector was very rapid. Therelease of the armature triggeredthe platen to rise against the printwheel. The actuation power forthe receiver was also provided bya falling weight drive. As the print-ing was able to take place with-out stopping the print wheel, itcontributed to its overall higheroperating speed than other sys-tems. Once the platen had oper-ated, it also reset the armature ofthe detector.

Hughes’ design actually inte-grated a transmitter and receiverinto one instrument and it wasdesigned from the start to operatein a duplex mode (able to trans-mit and receive simultaneously).It was also possible to actuallysend more than one letter perrevolution of the scanning cylin-der providing they were spaced anumber of letters apart (equal tothe time to recycle the receivingrelay). For example, the word“fly” could all be transmittedwithin one revolution, again fur-ther contributing to the speed oftransmission. The usual quotedaverage was three letters per revo-lution, and five was the maxi-mum.

To synchronize instrumentsthere was a procedure to be ac-complished. Instruments couldinitially be accurately set to runat close to the same frequency af-ter manufacture. Then, installedinstruments say in New York andPhiladelphia were first set to start

in phase. The transmitting instru-ment and receiving instrumentwere first latched in the “blank”position. In both instruments, themechanisms were all running ex-cept the print wheel which wasdeclutched from its rotating shaftand held at the blank position andin a wait mode. The transmittingoperator then pressed down theblank key on the keyboard. Whenthe receiver detected the blank sig-nal, it unlatched the print wheelsetting both instruments to run insynchrony. This clever arrange-ment also took care of instrumenttime lags and transmission linelags by automatically offsettingthe print wheel equal to the timedifference. As these time lagswould remain constant, the in-struments would remain in syn-chrony. Time lags up to one revo-lution of the print wheel could beaccommodated (0.5 sec for a ro-tation of 120 rpm).

Next, to ensure that both in-struments were running at thesame frequency, the followingprocedure was used. The trans-mitting instrument sent out astring of the letter “A”. If the re-ceiver printed out a series of A’sthen they were running at thesame frequency. However if thereceiver printed out letters thatwere running away say B, C, D,etc., then the receiver was runningtoo fast or if it was printing Z, X,Y, etc., then it was running tooslow. Thus, the frequency of thereceiver was adjusted until a se-ries of A’s was printed.

The electromagnet arrange-ment Hughes used in his detectorbecame known as the “Hughesquick acting electromagnet”. Thiscomponent was adopted for use bymany other inventors and appli-cations. One of these applicationswas with railway signaling andsafety systems used by Henry

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Latique in France and by Sykes’in Britain.

Hughes finally managed tocomplete his prototype instru-ments and get them to success-fully operate over telegraph linesin 1855 with an average speed of44 words per minute. Hughes’next move was to patent his in-struments and see if he could getthe telegraph companies interestedin buying the rights. At the time,there were many competing tele-graph companies with frag-mented operation covering theEastern part of America. One oftheir big customers was the news-papers, and in particular, the As-sociated Press (AP), who had anongoing battle to reduce the costof sending their dispatches overthe Morse dominated telegraphlines.

It was also a time when CyrusW. Field had entered the telegrapharena with his grand plan to spanthe Atlantic with an undersea tele-graph cable.8 However, he and hisassociates realized that to maketheir plan work they needed topull the fragmented telegraphcompanies into a cohesive opera-tion to be able to provide forsmooth message flow to and fromtheir Atlantic cable if it was to bean economic success.

When Hughes had barely com-pleted his prototypes, the AP gotwind of his invention and sum-moned him to New York. If theycould acquire Hughes’s telegraph,they could put pressure on theMorse telegraph companies bythreatening competition to forcereduced rates and possibly bringabout some cohesion in the indus-try. AP’s common objective withCyrus Field and the availability ofHughes’ new instrument providedthe impetus for the New Yorkbusinessmen to move forwardwith some bold plans and form the

“American Telegraph Company”(ATC) with Peter Cooper as presi-dent and Cyrus Field, DavidHughes and others as corporateexecutives.9

The AP played a prominent rolein bringing this about. Hugheswas offered $100,000 for his tele-graph system - a sum that musthave been beyond his wildestdreams. This was to set a patternfor his life, as he always seemedto be just in the right place at theright time with the right product.He was however unaware thathis invention was to be a pawn inthe American Telegraph Com-pany business dealings. The APand ATC now had a competingtelegraph system and some cloutto use against the Morse compa-nies to start forcing them to amal-gamate with the ATC and reducetheir costs.

Hughes’ instrument was as-sessed as not being robust enoughto survive the daily use by tele-graph operators. To solve this, theATC put their experienced ma-chinist, George Phelps to workwith Hughes in upgrading the in-strument.10 A relationship thatwas not always harmonious. Theyoung Hughes protective of hisinvention and the more seniorPhelps - an experienced machin-ist and familiar with the telegraphinstruments of the day was prob-ably full of ideas as to how to im-prove the mechanisms.

The eventual outcome how-ever was an instrument that wasmore robust and incorporatedvarious changes and improve-ments. These were replacing thetypewriter type letter keys with apiano style keyboard, changingthe mechanical scanning mecha-nism to a rotating commutator,beefing up the clockwork mecha-nism, adding a corrector mecha-nism to keep the instruments in

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tight synchronism and combiningthe transmitter and receiverweight drive mechanism. Manu-facturing commenced and the in-struments started to be put intoservice. Hughes patented hisoriginal telegraph in England in1855 and America in 1856.11 (Fig.6).

By 1857 Cyrus Field was readyto make another attempt to lay acable across the Atlantic and in-vited Hughes to England to joinhim. Hughes couldn’t refuse thechallenge and was drawn into theproject. The fact that there wasinsufficient knowledge at the timeto know if an electrical signalcould be sent through 2000 milesof wire lying under great pressuretwo miles below the ocean hadn’t,so far, deterred Field! The Atlan-tic telegraph cable is a story untoits self that ended up spanning sev-eral years before finally succeed-ing.12

Hughes’ involvement briefly

spanned the summer and fall of1858. He traveled to Englandwhere he attempted to make hisinstrument operate over the cablewhile it was in storage in tanks atthe shipyard. Undersea cables haddifferent characteristics to the tra-ditional telegraph lines strungabove ground on poles. The dif-ference being its significantlyhigher capacitance that had theeffect of almost swallowing elec-trical pulses, which becameknown as the “embarrassment” ofthe cable. Hughes was to meetWilliam Thomson (later to be-come Lord Kelvin) in England,who was a few years older thanhimself and who had taken thetime to devise a formula for thepropagation of electrical signals insubmarine cables.13 His telegraphequation or law of squares indi-cated electrical pulses would ex-perience an increasing time delayas they traversed the cable,known as retardation. A delay in

Fig. 6. Later model of Hughes’ telegraph instrument

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a 100 mile cable would not justincrease by a factor of 10 in a 1000mile cable (if it was linearly pro-portional) but would increase bya factor of 100. Along with thiseffect, the signal would also expe-rience attenuation. Thus, sendingsignals over the cable presented asignificant challenge to the instru-ment technology of the day. Thespeed that messages could betransmitted was an all-importantparameter as the operating eco-nomics of the transatlantic cablewere dependent upon it.

Unfortunately the electricianfor the transatlantic cable, W.W.Whitehouse did not agree withThomson (an unpaid advisor) andhad his own ideas as to how tosend signals through the cable.Hughes was caught in betweenconflicting views and at the sametime tried to modify his instru-ment to run significantly slowerto work over the cable. His efforthowever came to a sudden stop inthe fall of 1858 as the cable thathad operated for a couple ofmonths went dead.

After the cable failure, Hughestried to break into the British mar-ket dominated by the established“Cooke and Wheatstone” tele-graph system, with no success. Hecontributed to the government’sboard of enquiry into the transat-lantic cable failure. He believedone of the problems was the fail-ure of the insulation. To addressthis he invented a self-sealingsemi- fluid insulation. The ideawas that if the gutta percha insu-lation became punctured the fluidwould ooze into the void and re-seal it.14

Hughes had decided that therewasn’t much point in returning toAmerica since ATC owned therights to his instrument and thetelegraph industry was starting tobecome monopolized by them,

and eventually, Western Union.His instrument was subsequentlyfurther modified by Phelps whocombined some of the featuresfrom the Hughes and House in-strument with his own to con-struct an instrument that becameknown as the “Combination In-strument” that remained in ser-vice for many years.

Somewhat disillusioned in Brit-ain, Hughes headed for Francewhich was using a fairly old sys-tem of their own invention. Itturned out they were about readyfor an upgrade and open to evalu-ating new systems. After a suc-cessful trial period, his telegraphsystem was adopted in 1861 -again he just happened to be in theright place at the right time. TheFrench put his system into use onthe heavily used telegraph linesand were happy enough with thesystem and Hughes’ performancethat they presented him with theImperial Order of the Legion ofHonor by Emperor Napoleon IIIin 1864. Unlike America, (and ini-tially Britain), where the tele-graph companies were private orpublicly traded, the continentaltelegraph companies were all staterun.

Adoption of his system thenspread to Italy, Russia, Germany,Turkey, Holland, Switzerland,Belgium, Spain and Serbia until itwas in operation throughout Eu-rope. It became the standard forall international lines specified bythe International TelegraphicUnion.15

Whilst England initially hadgiven Hughes the “not inventedhere” treatment when he had triedto introduce his telegraph previ-ously, they eventually had toadopt his instruments to be com-patible with the rest of Europe.(Although there was some rumorthat they removed his name from

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the instrument to avoid embar-rassment!). His instruments wereput in to use by the United King-dom Electric Telegraph Companyof which Hughes also became adirector. By 1869, his instrumentswere in routine service on manyof the cross channel underseacables.16

By the 1870’s Hughes’ tele-graph, system was in widespreaduse throughout Europe as well asin South America. As a tribute toits design, it continued in servicefor nearly 100 years finally end-ing its service in the 1940’s.Hughes spent most of the 1860’sand early 1870’s based in Paris,travelling widely on the continentin support of his telegraph sys-tems where he had licensed anumber of manufacturers. Dur-ing this time he continued to makeupgrades and improvements.These included adding numbersand symbols providing up to 56characters, providing tactile feed-back to the operator so as to knowwhen a character had been trans-mitted, improvements to the tim-ing mechanism and changingover to electric motor drive.

He became known as one ofthe expert telegraph engineers ofthe day who was not just in thebusiness of selling instruments butin the business of promoting acommunication system. He wasalso called on to investigate thegrowing problems of electrical in-terference and lightning strikes ontelegraph installations. He wasrecognized for his service as hebecame one of the most decoratedscientists of the day receiving hon-ors from all the countries he hadsystems in. He also received theGold Medal at the Paris Exhibi-tion in 1867, along with CyrusField.

THE TELEPHONE ERAIn 1877, Hughes decided to

move to London, then consideredthe scientific epicenter. His tele-graph system had been so suc-cessful that he had become rela-tively wealthy, allowing him tobecome financially independent.He was now regarded as one ofthe pre-eminent telegraph men inEurope and was about to take hisplace in the scientific circle as anindependent researcher.

Alexander Graham Bell hadjust introduced his telephone, andit was the talk of the town.17

Whilst it was a wonderful inven-tion, it had its limitations.Hughes, along with others, wasquick to recognize this. Bell’s tele-phone used the same electromag-netic component and diaphragmboth as a receiver and transmit-ter. While it worked well for theformer, it lacked power as a trans-mitter and therefore was limitedin its signal output, and hence itsrange of transmission. Hughesdecided it would make a good re-search project.

While he recognized the com-ponents as functioning pieces ofthe telephone he saw them also assplendid pieces of test equipment.The telephone receiver, for him,was a device that enabled theamplitude and frequency range ofsignals to be easily measured forthe first time over a wide dynamicrange. He constructed a numberof receivers for his own use aspieces of laboratory equipment.Next, he turned his attention tothe transmitter. Hughes had ac-tually used and demonstrated anearlier version of a telephone in1865, when he borrowed a“Telephon” from Prof. Philipp Reisthe German scientist. At the timehe had been in Russia installinghis telegraph system when he wasrequested to give a lecture to the

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Czar and notables on the tele-graph and other electrical devices.He included Reis’s telephone in thepresentation. The Reis telephonehad actually been the startingpoint for many of the early tele-phone experimenters such as Belland Edison. Hughes made someexperiments trying to improve onReis’s approach but they wereunsuccessful.

He next started his enquiry bypondering if there was a materialor substance that could convertsound directly into electricity. Thisline of reasoning was based on thefact that it had been discoveredthat selenium altered its electricalcharacteristics when exposed tolight. William Thomson had alsoshown that placing a wire understrain resulted in a change to itsresistance.18 Hughes decided topursue this approach. He set up astretched wire to see if he couldget it to vibrate when exposed tosound waves, believing that if itdid then the strains experienced bythe wire would change its resis-tance which in turn could be de-tected.

His circuit consisted of a bat-tery, the stretched wire and thetelephone receiver, all connectedin series. Fortunately, the experi-ment failed, but it was a failurethat set him on a path of discov-ery. Hughes was a great experi-mentalist and seemed to be ableto sniff out which way to proceed.In the failed experiment, whichresulted in the wire being so ex-tended that it broke, he noticed atthe point of failure that he couldhear in the telephone receiver arushing sound and then a finalcrackle. Too many a broken wireor loose connection would be anannoyance but he was intriguedby the sounds he heard when thewire broke, it was something to beinvestigated. He tried holding the

wires together and found thatnoises could be heard, he then laidthe wires down on the table oneon top of the other slightlyweighted to hold them togetherand was surprised that he couldhear sound.

He embellished this experi-ment by laying three nails downto form a letter “H” and connectedthem into his circuit. Now hecould hear even better – but notwith much fidelity. He had dis-covered the loose contact effect asa means of detecting sound. Hisbasic apparatus relied on beingable to modulate a current by theloose or poor contact. It was adevice whose resistance changedin accordance with the soundwaves, just what he had been look-ing for. He went on to try manydifferent arrangements and ma-terials in a quest to improve thequality of the sounds he couldhear. Some of these were glasstubes filled with metal filings,with charcoal pieces or charcoalpowder as well as charcoal thathad been impregnated with mer-cury. (Fig. 7).

He tried many types of mate-rial contacts and found that met-als that oxidized became unusable.Materials that didn’t oxidize wereplatinum and carbon – and hechose the more economical of thetwo. As he refined his devices hefound the most successful werebased on a carbon pencil looselysupported between two carbonsupports mounted on a piece ofwood or sounding board. Thesehe connected in series with a bat-tery and the Bell receiver. Henamed it a “microphone” - a mag-nifier of sound (in keeping withthe microscope that magnifiedlight). It was a true microphonein that it had many more appli-cations other than just as a tele-phone transmitter.

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He had discovered a true mi-crophone that could be made sosensitive that a fly could be heardwalking about on it. He declinedto patent the microphone declar-ing that he was giving the tech-nology away free to be used byanyone. His experiments werepublished by the technical societ-ies and in many of the technicaljournals.19 The floodgates soonopened and within months, oth-ers were repeating his experimentsand working on their own ver-sions. Variations of the carbonpencil microphone were exten-

sively used in conjunction with anelectromagnetic receiver in Eu-rope for many years by severalcompanies. A later variation,based on Hughes’s demonstrationof the use of particles in loose sur-face contact, resulted in the car-bon granule microphone of HenryHunnings.

In America this technologywas further developed by A. Whiteinto what became known as thesolid back transmitter and in theUK as the Post Office insert num-ber 13 microphone. The carbongranule transmitter was not su-

Fig. 7. Various Hughes microphones.

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perseded by any other technolo-gies for use in telephones until the1980’s (and in some parts of theworld they are still in use!).Hughes’s theory as to how themicrophone worked was that itwas a surface effect due to thenumber of points in contact thatvaried in sympathy with the soundwaves.

Hughes was a man of shortstature, blue eyes deeply set un-der bushy eyebrows, flowingchevelure and walrus moustache.He was mild mannered, indepen-dent, sometimes stubborn, butgenial and sympathetic. He wassaid to be always full of interest-ing experiences and of a lightheartedness that made him excel-lent company. However at timeshe become a catalyst (or as someviewed it a lightning rod) forstimulating great debates withinthe scientific community, eitheron the theory of electrical phe-nomena or on his experimentalresults.

One of these instances cameabout with his discovery of thecarbon microphone when hecrossed swords with ThomasEdison. Edison believed he hadinvented the carbon microphonefirst and suspected one of the En-glish government officials (Will-iam Preece), whom he had con-fided in, of leaking his secrets toHughes. Hughes’s decision to giveaway his invention freely to theworld only further infuriatedEdison, who intended to capital-ize on this invention. Unfortu-nately, the “Wizard of MenloPark”, as Edison was known, hadmisunderstood the circumstances,and before checking and discuss-ing with Hughes, or others that hewas accusing, immediately tookthe dispute public in the newspa-pers. Therefore, an affair thatcould have been settled amiably

became a nasty war of words andaccusations and counter accusa-tions dragged out in the majortechnical journals and newspa-pers.

The dispute drew in the who’swho of the scientific world, whowaded in with their opinions andin support of their respectivechampion. The dispute eventuallybecame nationalistic pitting themuch larger scientific communityof Europe against the smaller oneof America. In the end, it wasconcluded that each had carriedout their research independentlyand there had been no leaks.Hughes, having discovered in themicrophone a device that hadwide applications and Edison hav-ing concentrated specifically onthe telephone transmitter. Thechief scientist of the day in Brit-ain, Sir William Thomson (LordKelvin) scolded Edison in the pressover the affair and requested anapology from him for his un-founded accusations - Edisonnever did reply.

THE INDUCTION BALANCEHughes recovered from the as-

sault on his character, and in Eu-rope, at any rate, he was laudedas the inventor of the microphone.The months of publicity had alsoelevated his name and statusamongst the scientific commu-nity and the public. Hughes wasnext to turn his attention to a vex-ing problem, that of interferenceon telegraph wires. He had inves-tigated the problems some yearsearlier while in France, and nowthe problem had taken on a newurgency with the introduction ofthe telephone. When the telephonewas introduced, it made use of thesingle iron wire telegraph lineswith an earth return, which wasfar from ideal. In the cities, the

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telegraph caused significant inter-ference for the telephone. Hughesset to work experimenting to un-derstand the nature of the inter-ference.

He set up a simulation in hislab of telegraph lines using wirecoils to simulate lines of manymiles in length and whose prox-imity could be varied to simulatethe coupling. The outcome of theresearch was a solution for sup-pression of interference on mul-tiple lines. The research alsoyielded the use of twisted wirepairs for telephone use and the useof shielded wire (coax). However,it would be many years beforethese techniques were put intouse.20

In doing research with the in-duction coils that canceled outunwanted signals, he noticed thatthey were also sensitive to thepresence of small amounts ofmetal. This led him to further ex-periments, resulting in the Induc-tion Balance.21 The device con-

sisted of four coils (two primaryand two secondary) that were con-nected and carefully positioned soas to be in opposition to eachother, so that when the primarywas excited by a pulsed source andthe secondary connected to a tele-phone receiver no sound could beheard. Hughes’ pulsed source con-sisting of his microphone in closeproximity to a loud ticking clockand the newfound sensitive detec-tor, the “telephone receiver”,turned the arrangement into auseful device. 22 If a small piece ofmetal was introduced into one setof coils the arrangement wouldbecome unbalanced and thiscould be detected in the receiver.( Fig 8.)

The apparatus was extremelysensitive, being able to detectminute quantities of metal or al-ternatively was able to comparetwo like samples. The device founduse at the Royal Mint to compareand check metal alloys used forcoinage. Whilst the device proved

Fig. 8. Hughes’ Induction Balance and Sonometer

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useful, there was still much to beunderstood about induction inmetals, such as eddy currents,that were still unknown. Hughes’induction balance was the fore-runner of today’s “metal detector”,now in wide use as a recreationdevice to look for buried treasureon the shore, in the process indus-try for detecting metal fragmentsin fluids, etc., and standard equip-ment at security checkpoints. Outof this research came a numberof interesting off shoots.

One was a device he called a“Sonometer” that consisted of twocoils mounted on either end of agraduated ruler. A third coil wasmounted between these coils andwas free to slide along the ruler.(see fig. 8). The end coils wired inopposition and were excited by thepulsed source. The sliding coilwas connected to the telephonereceiver. When the sliding coil wasat midpoint along the ruler it ex-perienced a null and no soundcould be heard in the receiver.Sliding the coil towards one endincreased the volume of the sig-nal whose value could be corre-lated with the scale on the ruler.Hughes used this in conjunctionwith his induction balance as ameans of making relative mea-surements. This was done byswitching the telephone receiverback and forth between the induc-tion balance and the sonometeruntil the relative volume of thetwo signals was judged the same.The reading was then taken off theruler scale. The sonometer wasalso adopted by the medical pro-fession and used extensively fortesting hearing.

One of the more famous usesof Hughes’ induction balance wasAlexander Graham Bell’s applica-tion of it in 1881 in the desperateattempt to try to determine wherethe bullet had lodged in President

Garfield, while he clung to life af-ter being shot by an assassin. Bellconsulted with Hughes but despitehis best efforts, he was unable tolocate it before President Garfieldsuccumbed.

WIRELESS DISCOVERY IN1879?

Hughes was a great experi-menter, and nowhere is it moreapparent than when reading hisnotebooks.23 Here the experi-ments come alive as the reader fol-lows the scrawled handwritingfrom one page to the next. He wasmethodical and innovative, hispeers saw him as a gifted experi-menter as he seemed to have theability to be able to hit on the rightapproach or combination of ex-periments that brought about suc-cess. His next discovery was prob-ably his most innovative, but wasto be a bittersweet story. His ex-perimentation, resulting in thediscovery of wireless, became vir-tually hidden for many years andhis discoveries only becameknown in the waning years of hislife. His experiments took place anumber of years before Hertz andMarconi. History finally creditedhim with the discovery but overtime it has slipped off the pages ofhistory.

It all came about whenHughes was experimenting withhis induction balance in the fall of1879. He had started with a pri-mary circuit consisting of a set ofcoils being pulsed from a batteryby clockwork driven contactor. Asecondary circuit consisted of asecond set of coils inductivelycoupled to the first that were con-nected to a telephone receiver.When he rearranged this configu-ration, it gave him some unex-pected results – in that he couldstill hear the make and break sig-

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nal even when he thought heshouldn’t. He suspected it was ei-ther due to an effect called the “ex-tra current” (the current inducedin an inductor when its magneticfield rises or collapses) or thebreakdown in the insulation ofone of the coils.

However, it turned out to be aloose connection between somewires. As the effect was puzzling,he pursued it, substituting oneloose connection for another byinserting one of his loose connec-tion microphonic joints from hismicrophone experiments. Still hecontinued to hear the signal in histelephone receiver. The mysterygrew as he separated the primarycircuit from the secondary bysome distance and only connectedby a single wire. He was strug-gling to understand how the sig-nal could be heard with a circuitthat was apparently incomplete -that is an open circuit.

He also experimented by re-moving the coils from the second-ary part of the circuit and he couldstill hear the signal of the makeand break in the telephone re-ceiver. He then proceeded to thenext inevitable step. He cut theconnecting wire and still couldhear the signal. He was baffled andrationalized that the signal mustbe traveling between the two cir-cuits by “conduction” through thebuilding structure. Initially thegap between the two circuits wasonly six feet. He then moved thereceiver (although Hughes didn’tuse this term until much later) tothe next room, and eventuallysome 60 feet of separation.

What was significant was thathe was detecting the make andbreak with a receiver in which thesecondary coils had been removedand consisted only of a telephonereceiver in parallel with his micro-phonic joint. In these experi-

ments, he had started to groundone side of the circuit to either agas pipe or water pipe (not un-usual for a telegraph engineer).He also took the receiver a coupleof floors down in his house to hisbasement where he could stillplainly hear. He grounded the re-ceiver to one of the pipes and be-lieved the signal grew louder andput this down to the fact that thedifferent metals were creating abattery effect. This led him to adda small low voltage battery to thereceiver circuit with the micro-phonic joint.

To solve the mystery as to howsignals were traveling betweenthe transmitter and receiver hesuspended the receiver by non-conducting cords from the ceilingand concluded that it could nolonger be conduction through thehouse structure but the signal wascoming through the ether (the airwas considered to be more com-plex in the Victorian period). Heconcluded it was traveling by linesof force and the more of them heintercepted the louder he couldhear the signal. It is surmised hecame to this conclusion by com-paring it to the invisible lines offorce that surround a magnet orcurrent carrying conductor.

Although he continued to callthe device a microphonic joint ithad become a detector andthrough extensive experimenta-tion it had taken on a much dif-ferent form and characteristics.His experiments revolved aroundtrying to improve this device sothat he could hear signals louder.He settled finally on two configu-rations for the detector: one ofoxidized copper wires looped to-gether, and the other a steel needleresting on a piece of coke. He en-capsulated these detectors intosmall bottles for protection. Inarriving at these he had also tried

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many other forms of his micro-phone components with mixedresults such as a glass tube filledwith metal filings and iron wiresdipped into mercury.

Hughes next took his receiverand walked out into the street andcontinued walking, and was stillable to hear the signal until by500 yards it had faded away. Thiswas an embryonic “wireless” ex-periment but the phenomenon ofcreating the invisible electromag-netic waves and being able to de-tect their presence was unknownat the time. It is interesting to notethat his previous inventions of themicrophone and induction bal-ance and his use of the telephonereceiver were all necessary prereq-uisites and essential ingredientsleading up to this discovery. (Fig9).

Hughes was a scientist of theschool that was called “the prac-tical men” whereby discoverieswere made by experimenting.Any supporting theory or formulawas a rarity and quite often re-garded as suspect by these “prac-tical men”. However there was anew breed of scientist surfacing.These were mathematicians and

physicists who tackled problemsfirst from a theoretical point ofview. One such person wasJames Clerk Maxwell, a brilliantScottish mathematician andphysicist working at CambridgeUniversity. In the 1870’s he pre-dicted mathematically the theoryof electromagnetic radiation, (thebasis of wireless signals), a theoryhe amazingly developed withoutany experimental evidence or in-dication of how electromagneticwaves might be produced or de-tected. Looking back, this wasprofound, and its impact wasn’tfully understood at the time.

Meanwhile, just over 50 milesaway in London, Hughes had ex-perimentally demonstrated justwhat Maxwell had predicted andhad produced electromagneticwaves and detected them – whichwas the experimental validation ofhis theory and the missing link.Unfortunately, fate was to inter-vene, Maxwell died young in 1879,the year Hughes made his discov-eries, and Hughes, who was not amathematician, would not havebeen able to decipher Maxwell’scomplex mathematical equations.

Hughes, however, was so ex-

Fig. 9. Hughes wireless components.

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cited by what he had discoveredthat he repeated his experimentsin 1880 to important members ofthe Royal Society, the premier sci-entific organization of the daythat included Professor GabrielStokes. Stokes was also from Cam-bridge University and a math-ematician who knew Maxwell andwas aware of his work. Could hepossibly make the connection be-tween Maxwell’s theories andHughes experiments? However,it all unraveled, and what couldhave been the start to a brilliantdiscovery, possibly Hughes great-est, and the verification ofMaxwell’s work was stopped dead.Stokes observed the experimentand stated that it was not a newphenomenon and could be ex-plained by already known facts ofelectromagnetic induction. Hefailed to make any connectionwith Maxwell’s theories or recog-nize it as a new phenomenon. Itwas just like pricking a balloon,dashing Hughes’s hopes andswaying the opinion of the otherobservers in the process. Thus, apromising discovery, instead ofbeing encouraged, was scuttled.Hughes was frustrated and angryafter the meeting. For some rea-son, though, Hughes did not ap-pear to have talked about histheory of the signals being trans-mitted by lines of force, but talkedabout conduction, probably con-fusing the issue.

Hughes was, however, reluc-tant to cross Professor Stokes, aman whose opinion was so widelyinfluential. It is unfortunate thatthese experiments were not dis-closed to scientists with a betterunderstanding such as OliverLodge or George FrancisFitzGerald. These two young sci-entists had become fascinated byMaxwell’s work and could haveperhaps grasped the significance

of Hughes experiments, and socould have advised him accord-ingly.

Hughes by this time had prob-ably become aware that he wasto be proposed for membership tothe Royal Society, a status that hedeeply sought. This provided afurther reason not to strike anydiscord with Stokes or the othermembers of the Royal Society forfear of jeopardizing his election.Had Hughes’ work been recog-nized at the time it would havepre-dated Hertz by nearly a de-cade and Marconi by two decades.

As it was, his wireless experi-ments were not to come to theattention of the general scientificcommunity for another twentyyears when Sir William Crookesmade some remarks about wit-nessing some of Hughes wirelessexperiments many years earlier.The author J.J. Fahie, who wasclose to completing a book on the“History of Wireless Telegraphy1839-1899”, was, like many oth-ers taken completely unaware. 24

He immediately contactedHughes to follow up on Crookesremarks. Hughes at first was re-luctant to divulge the informa-tion, unwilling to upstage thework of Hertz and Marconi thathad occurred in the interveningyears. A generous gesture. Fahiewas eventually successful in per-suading Hughes to relate to himthe experiments and includedthem into his book. They werealso recounted in a number oftechnical journals.

Hughes did become a “Fellow”of the prestigious Royal Society in1880 and continued research andexperimentation. He had alwaysbeen interested in the molecularaspect of materials and magneticproperties of metals and it is to thisthat he next turned his attention .During the early 1880’s, he pre-

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sented many papers on such top-ics as “Molecular Rigidity of Tem-pered Steel”, and “The Cause ofEvident Magnetism in Iron, Steel,and other magnetic Metals”. He,like other scientists, was deeplyinterested in what magnetism was.He presented papers on “Molecu-lar Magnetism” and “Theory ofMagnetism based upon New Ex-perimental Researches”. Duringthe course of the experiments, hedevised a new instrument calleda “Magnetic Balance” that en-abled magnetic strengths to bemeasured.25

It was during this period in the1880s that it seems Hughes finallymanaged to find time to marry hislong time friend from Paris - AnnaChadbourne in 1882. She was anaccomplished artist, a resident ofParis and also an American citi-zen. She had been widowed anumber of years earlier when herhusband, Charles Morey, a pro-moter of Goodyear’s vulcanizingrubber process, was unfortu-nately, due to a misunderstand-ing, put in debtors prison, wherehe was accidentally and tragicallyshot by a prison guard.26

For Hughes his wife was a greatsupporter of his work and a greathelp with the many social require-ments and engagements of thevarious societies that he belongedto. It is due to his wife that we havesome documentation on his life,as it was she who made copies ofhis letters and made small notesof his memories of his early life.

In 1886, Hughes was electedPresident of the Society of Tele-graph Engineers (later to becomethe Institute of Electrical Engi-neers). Ducking the usual formalacceptance speech Hughes de-cided instead to share with thesociety some of his resent re-searches. The subject was: “TheSelf Inductance of an Electric

Current in Relation to the Natureand Form of its Conductor”.27 Hewas aware that he had obtainedsome unexplained results andhoped that by sharing them withthe members of the society itwould result in some discussionand possible explanation which hecertainly got. He probably wasn’tready for the torrent of commentsand depth of discussion that fol-lowed.

The experiments he presentedhad been conducted to investigatethe interference on telegraph linesduring the transient switchingperiod such that occur with theleading and falling edges of pulses.It was an area that had receivedlittle attention, but was believed tobe the cause of many of the prob-lems that still plagued the indus-try. The results he presentedstimulated an interesting out-come. Hughes like many of themembers of the Society was oneof what were called the practicalmen – those who had come abouttheir knowledge via hands-on ex-perimentation and years of expe-rience. There were also membersof the society who were academ-ics and who had risen throughtheir university training. Theywere, however, in the minorityand were viewed with suspicion bythe practical men, whose attitudewas, if they hadn’t been “fieldtested”, how could they have any-where near the knowledge of thepractical men.

There was also the matter ofterminology that led to miscom-munication between the practicalmen and the theoreticians. Stan-dardization of electrical terms wasstill in its infancy and it was notuncommon therefore for terms tobe invented, especially by thepractical men.

When Hughes presented hisexperiments and results they were

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totally contrary to what the aca-demics would have expected. Thistime they couldn’t sit by and notchallenge them. Lord Rayleighbecame their spokesman and be-lieved that Hughes’s equipmentwas in fact not measuring whathe believed it was.28 Hughes hadmade his experiments based on amodification of his induction bal-ance. Rayleigh was an excellentspokesman working with Hughesin a non combative manner todelve into his experiments andending up devoting a year of histime to help sort it all out. The dis-section of Hughes experimentsand discussion in the technicaljournals ranged far and wide.

It turned out that Hughes ex-perimental apparatus was flawedand thus the majority of his re-sults were incorrect. Nevertheless,there was one set of experimentsin which the academics saw somemerit. On the recommendationof Rayleigh and others Hughesmodified his apparatus and reranthe experiments, this time obtain-ing less controversial results. How-ever in the one area that had pre-viously shown some merit,Hughes obtained additional im-portant data.

For one scientist though, thewhole episode had proved toomuch. This was the reclusive sci-entist Oliver Heaviside who neverventured out to any of the scien-tific meetings but communicatedvia letters and through the tech-nical journals.29 He had been pub-lishing highly mathematical pa-pers for some time in the journalThe Electrician which had drawnlittle attention. Now he saw inHughes’ experiments some resultsthat appeared to verify a math-ematical analysis he had made theprevious year. Not wanting to loseout on the credit he also joined thediscussion. It turned out what

Hughes had demonstrated was anincrease in a conductor’s resis-tance with an increase in a signal’sfrequency. This was to becomeknown later as the skin effect,whereby the higher the frequencythe more the current crowded tothe surface of the conductor re-sulting in an increasing resistance.At RF frequencies the currentflows only in the skin of the con-ductor. Oliver Heaviside hadmathematically proven this,which he called the thick wire ef-fect and took Hughes’ experimentsas the practical verification of hisformula.

For the theoreticians it wasverification of their worth, thattheory could predict a practicaloutcome and was starting to ex-plain many of the mysteries thatsurrounded electricity and mag-netism. Oliver Heaviside’s workfinally started to get the recogni-tion it deserved. Hughes’ experi-ments had finally provided theopportunity for him to shine andit was to be the turning point fromwhere the theoreticians or the“new school” as Hughes calledthem, started to come into promi-nence and the old school practi-cal men’s influence started to fade.

Hughes continued to be recog-nized for his scientific contribu-tions and in 1885 was awarded theRoyal Medal from the Royal So-ciety. He was also active with theRoyal Institution becoming theirVice President in 1891. The RoyalInstitution had had such presti-gious past presidents as SirHumphrey Davy and his protégéMichael Faraday.

Hughes realized as time wenton that his breakthrough inven-tion period was probably over. Hestill continued to receive moneyfrom the success of his telegraphsystems and he had judiciouslyinvested it providing him with a

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sound financial base. He and hiswife, while enjoying a comfort-able lifestyle, were not extrava-gant, and elected to live in anapartment on Great PortlandStreet and later around the cor-ner in Langham Street. They en-joyed an extended tour of Europeeach summer.

Hughes started to redirect hisenergies in other ways such ashelping younger prospective engi-neers and scientists on their way.He was keen on seeing them getahead with an education especiallyif they showed initiative in help-ing themselves. To be in a betterposition to promote and influencethem, he became associated withthe London Polytechnic School ofEngineering and became theirPresident. He took the job seri-ously and often stayed up late atnight writing letters of encourage-ment and advice to students, giv-ing them hints and opinions ontheir inventions or experiments.

He continued to be recognizedfor his work and was awarded theAlbert Medal in 1897. A medal thatFaraday, William Thomson (LordKelvin), Louis Pasteur and Sir Jo-seph Lister had previously re-ceived. As the century came to aclose his health started to deterio-rate and he barely saw the NewYear in as he died on 22 January1900 and was laid to rest inHighgate cemetery.

Always generous in life he wasalso generous after his death.Hughes’ estate was valued at£472,704, ($2,268,979). 30

Hughes was in the minority, be-ing a self-made scientist who ac-tually was a financial success.After providing for his wife andrelatives he left a substantialamount of his wealth to the Lon-don hospitals in the form of “TheDavid Edward Hughes HospitalFund”. This fund is still in opera-

tion today and still providing ben-efits to the hospitals.

To the professional organiza-tions he left sums of money to es-tablish medals, awarded annuallyin recognition of original scientificresearch. The Hughes medal con-tinues to be awarded annually atthe Royal Society and has beenawarded to such notables asStephen Hawking in 1976 andAlexander Graham Bell in 1913,as well as: Max Born, RobertWatson Watt (Radar), H. Geiger,Neils Bohr, Edward Appleton,Ambrose Fleming and AugustoRighi.

BIBLIOGRAPHYThompson R.L. Wiring a Continent,

Princeton University Press. 1947.Huurdeman A.A. The worldwide

History of Telecommunications.John Wiley & Sons Inc. 2003.

Bruce R.B. Alexander Graham Bell,Little, Brown, and Co Boston1973.

Fahie J.J. A History of WirelessTelegraphy 1838-1899, Williamand Blackwood and sons 1899.

Nahin P.J. Oliver Heaviside. IEEEPress, NY.

DEHNB. Refers to: David EdwardHughes Notebooks are in theBritish Library London. RareManuscripts Collection. Add MS40641, 40642, 40643, 40644,40645, 40646, 40647, 40648A &B, 40161, 40162 and 40163.

DEH Papers, refers to: Copies ofHughes papers that are at theMicrofilm Archive for VictorianTechnology, Edited by J.O. Marshand R.Glyn Roberts. TheNorthwestern Museum of Scienceand Industry and Dept. of Historyof Science and technology UMIST.Manchester, UK. 1980.

NOTES1 The early history of the Hughes

family is recorded in two Welshnewspaper reports in Baner acAmserau Cymru, English

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translation Welsh Standard andTime Sept. 13 and 20, 1865. Alsoin the London Welsh Magazine YDolan (The Link), 1932.

2 DEH Papers.3 DEH Papers.4 Lardner. D.L. The Electric

Telegraph, Walton and Maberly,London 1855.

5 Ibib.6 DEH Papers.7 Specification given in English

patent # 2058, 1855.8 Carter. S. Cyrus Field Biography,

Putnam’s Sons, 1968.9 Thompson R.L. Wiring a Continent,

Princeton University Press. 1947.10 George M. Phelps – Instrument

maker, John Casale, AWA OldTimers Bulletin Part 1, May1999,Pg. 21-23. Part 2 August1999, Pg. 41- 43.

See also Web Site (http://www.te legraph-history .org/george-m-phelps/).

11 English patent # 2058, 1855.American patent #14917, 1856.

12 Burns B. Web Site: History of theAtlantic Cable & UnderseaCommunications from the firstsubmarine cable of 1850 to theworldwide fiber optic network.(http://atlantic-cable.com/).

13 Bart and Bart, Sir WilliamThomson, on the 150th

Anniversary of the Atlantic Cable,AWA Review Vol. 2, 2008. Pg. 121–163.

14 English Patent # 84, January 1859.15 Huurdeman A.A. The worldwide

History of Telecommunications.John Wiley & Sons Inc. 2003.

16 Reference Steven Roberts Web Site(http://distantwriting.co.uk/default.aspx) for acomprehensive coverage of theUK telegraph Companies.

17 Bruce R.B. Alexander Graham Bell,Little, Brown, and Co Boston1973.

18 DEHNB.19 Hughes D.E. “On the Sonorous

Vibrations in varying the Force ofthe Electric Current”. RoyalSociety May 9, 1878

20 Hughes D.E. ExperimentalResearches into means of

Preventing induction uponLateral Lines. Society ofTelegraph Engineers, March 12.1879.

21 Prof. Felici of Pisa. 1852, Ref. “ATreatise on Electricity andMagnetism” by James ClerkMaxwell, Vol. II, Art 536. Feliciexperimented with inductancecoils using a galvanometer as hisindication for balance whileswitching a battery on and off inthe primary circuit. The devicewas primarily for experimentingwith induction and mutualinduction

22 Hughes D.E. “On an Induction-Currents Balance, andExperiments and searches madetherewith” Royal Society May 15,1879.

23 DEHNB. See specifically Notebook# 40161.

24 Fahie J.J. A History of WirelessTelegraphy

25 Hughes D.E. “Molecular Rigidity ofTempered Steel”. Royal Society,Jan 1883; “The Cause of EvidentMagnetism in Iron, Steel, andother Magnetic Metals”. RoyalSociety May 24th1883;“Molecular Magnetism” RoyalSociety May 1881; “Theory ofMagnetism based upon NewExperimental Researches” RoyalSociety May 1883.

26 DEH Papers.27 Journal of the Society of Telegraph

Engineers and Electricians, Vol.XV 1886 No 60 Jan 28th.

28 Lord Rayleigh was the second –after J.C. Maxwell CavendishProfessor of Physics atCambridge. Rayleigh was awardedthe Nobel Prize for Physics in1904.

29 Nahin P. Oliver Heaviside, Sage inSolitude. IEEE Press NY.

30 The exchange rate in 1900 was£1=$4.8. It is difficult to make acomparison of monetary valuesover such a long time span but thiswas probably equivalent to$20milion in today’s value.

This article was peer-reviewed.

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ters it was both an exhilaratingand exciting experience on whichto end a career.

During his employment, Ivorwas awarded a number of patents.His career spanned the wide tech-nology transition that started withanalog circuits through the mixedanalog/digital period into the digi-tal and software driven designs oftoday.

Since his retirement, he hashad more time to devote to experi-menting and researching the his-tory of technology of telegraphand early wireless. For the last fewyears, he has focused in on his

PHOTO CREDITS

Fig. 1 DEH PapersFig. 2 DEH PapersFig. 3 American Telegraph,W.Maver.Fig. 4 I. HughesFig. 5 - Smithsonian Museum,WshingtonFig. 6 - Archive de FranceTelecom, ParisFig. 7 American Inventor, June1878.Fig. 8 Engineering, May 1879.Fig. 9 - Sciences Museum, Lon-don

ABOUT THE AUTHOR

Ivor Hughes spenthis early years in theUK and has had a lifelong fascination withelectronics. He initiallyserved as an apprenticein the telephone indus-try where he received agreat practical educa-tion that ranged fromthe basic telephonethrough to RF groupcarrier systems. Afterreceiving his BSEE hewent into R & D, work-ing on Navigation andAttack electronic sys-tems for aircraft for theBritish Aircraft Corpo-ration. In the late1960’s, he was recruited by UnitedTechnologies in the United Statesto work in their Electronic Avion-ics Division as a systems engineer.Here he was involved in electronicsystems design of jet engine pro-pulsion controls and flight con-trols.

In the 1970’s, he moved em-ployment to Goodrich Aerospaceto work as a system designer ofavionics systems. As the work alsoincluded flight testing in helicop-

namesake David Edward Hughes.The results of this research are tobe published in book form nextyear (2010) as a biography ofHughes.

Ivor Hughes