heroes of the telegraph-第34章
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； or 'drum；' vibrating under the waves of sound； and communicating its vibrations through the hammer…bone behind it to the auditory nerve。 It therefore occurred to him； that if he made a diaphragm in imitation of the drum； and caused it by vibrating to make and break the circuit of an electric current； he would be able through the magnetic power of the interrupted current to reproduce the original sounds at a distance。
In 1837…8 Professor Page； of Massachusetts； had discovered that' a needle or thin bar of iron； placed in the hollow of a coil or bobbin of insulated wire； would emit an audible 'tick' at each interruption of a current； flowing in the coil； and that if these separate ticks followed each other fast enough； by a rapid interruption of the current； they would run together into a continuous hum； to which he gave the name of 'galvanic music。' The pitch of this note would correspond to the rate of interruption of the current。 From these and other discoveries which had been made by Noad； Wertheim； Marrian； and others； Reis knew that if the current which had been interrupted by his vibrating diaphragm were conveyed to a distance by a metallic circuit； and there passed through a coil like that of Page； the iron needle would emit a note like that which had caused the oscillation of the transmitting diaphragm。 Acting on this knowledge； he constructed a rude telephone。
Dr。 Messel informs us that his first transmitter consisted of the bung of a beer barrel hollowed out in imitation of the external ear。 The cup or mouth…piece thus formed was closed by the skin of a German sausage to serve as a drum or diaphragm。 To the back of this he fixed； with a drop of sealing…wax； a little strip of platinum； representing the hammer… bone； which made and broke the metallic circuit of the current as the membrane oscillated under the sounds which impinged against it。 The current thus interrupted was conveyed by wires to the receiver； which consisted of a knitting…needle loosely surrounded by a coil of wire fastened to the breast of a violin as a sounding…board。 When a musical note was struck near the bung； the drum vibrated in harmony with the pitch of the note； the platinum lever interrupted the metallic circuit of the current； which； after traversing the conducting wire； passed through the coil of the receiver； and made the needle hum the original tone。 This primitive arrangement； we are told； astonished all who heard it。 ＇It is now in the museum of the Reichs Post…Amt； Berlin。＇
Another of his early transmitters was a rough model of the human ear； carved in oak； and provided with a drum which actuated a bent and pivoted lever of platinum； making it open and close a springy contact of platinum foil in the metallic circuit of the current。 He devised some ten or twelve different forms； each an improvement on its predecessors； which transmitted music fairly well； and even a word or two of speech with more or less perfection。 But the apparatus failed as a practical means of talking to a distance。
The discovery of the microphone by Professor Hughes has enabled us to understand the reason of this failure。 The transmitter of Reis was based on the plan of interrupting the current； and the spring was intended to close the contact after it had been opened by the shock of a vibration。 So long as the sound was a musical tone it proved efficient； for a musical tone is a regular succession of vibrations。 But the vibrations of speech are irregular and complicated； and in order to transmit them the current has to be varied in strength without being altogether broken。 The waves excited in the air by the voice should merely produce corresponding waves in the current。 In short； the current ought to UNDULATE in sympathy with the oscillations of the air。 It appears from the report of Herr Von Legat； inspector of the Royal Prussian Telegraphs； on the Reis telephone； published in 1862； that the inventor was quite aware of this principle； but his instrument was not well adapted to apply it。 No doubt the platinum contacts he employed in the transmitter behaved to some extent as a crude metal microphone； and hence a few words； especially familiar or expected ones； could be transmitted and distinguished at the other end of the line。 But Reis does not seem to have realised the importance of not entirely breaking the circuit of the current； at all events； his metal spring is not in practice an effective provision against this； for it allows the metal contacts to jolt too far apart； and thus interrupt the current。 Had he lived to modify the spring and the form or material of his contacts so as to keep the current continuousas he might have done； for example； by using carbon for platinumhe would have forestalled alike Bell； Edison； and Hughes in the production of a good speaking telephone。 Reis in fact was trembling on the verge of a great discovery； which was； however； reserved for others。
His experiments were made in a little workshop behind his home at Friedrichsdorff； and wires were run from it to an upper chamber。 Another line was erected between the physical cabinet at Garnier's Institute across the playground to one of the class…rooms； and there was a tradition in the school that the boys were afraid of creating an uproar in the room for fear Herr Reis should hear them with his 'telephon。'
The new invention was published to the world in a lecture before the Physical Society of Frankfort on October 26； 1861； and a description； written by himself for the JAHRESBERICHT； a month or two later。 It excited a good deal of scientific notice in Germany； models of it were sent abroad； to London； Dublin； Tiflis； and other places。 It became a subject for popular lectures； and an article for scientific cabinets。 Reis obtained a brief renown； but the reaction soon set in。 The Physical Society of Frankfort turned its back on the apparatus which had given it lustre。 Reis resigned his membership in 1867； but the Free German Institute of Frankfort； which elected him an honorary member； also slighted the instrument as a mere 'philosophical toy。' At first it was a dream； and now it is a plaything。 Have we not had enough of that superior wisdom which is another name for stupidity？ The dreams of the imagination are apt to become realities； and the toy of to…day has a knack of growing into the mighty engine of to…morrow。
Reis believed in his invention； if no one else did； and had he been encouraged by his fellows from the beginning； he might have brought it into a practical shape。 But rebuffs had preyed upon his sensitive heart； and he was already stricken with consumption。 It is related that； after his lecture on the telephone at Geissen； in 1854； Professor Poggendorff； who was present； invited him to send a description of his instrument to the ANNALEN。 Reis answered him；'Ich danke Ihnen recht Sehr； Herr Professor ； es ist zu spaty。 Jetzt will ICH nicht ihn schickeny。 Mein Apparat wird ohne Beschreibung in den ANNALEN bekannt werden。' （'Thank you very much； Professor； but it is too late。 I shall not send it now。 My apparatus will become known without any writing in the ANNALEN。'）
Latterly Reis had confined his teaching and study to matters of science； but his bad health was a serious impediment。 For several years it was only by the exercise of a strong will that he was able to carry on his duties。 His voice began to fail as the disease gained upon his lungs； and in the summer of 1873 he was obliged to forsake tuition during several weeks。 The autumn vacation strengthened his hopes of recovery； and he resumed his teaching with his wonted energy。 But this was the last flicker of the expiring flame。 It was announced that he would show his new gravity…machine at a meeting of the Deutscher Naturforscher of Wiesbaden in September； but he was too ill to appear。 In December he lay down； and； after a long and painful illness； breathed his last at five o'clock in the afternoon of January 14； 1874
In his CURRICULUM VITAE he wrote these words： 'As I look back upon my life I call indeed say with the Holy Scriptures that it has been 〃labour and sorrow。〃 But I have also to thank the Lord that He has given me His blessing in my calling and in m
