heroes of the telegraph-第47章
按键盘上方向键 ← 或 → 可快速上下翻页，按键盘上的 Enter 键可回到本书目录页，按键盘上方向键 ↑ 可回到本页顶部！
————未阅读完？加入书签已便下次继续阅读！
in railway trains； steamers； and other unsteady vehicles； it will be…used for communications。 The telephone may yet be adapted to work in conjunction with it； so that a phonogram can be telephoned； or a telephone message recorded in the phonograph。 Such a 'telephonograph' is； however； a thing of the future。 Wills and other private deeds may of course be executed by phonograph。 Moreover； the loud…speaking instrument which Edison is engaged upon will probably be applied to advertising and communicating purposes。 The hours of the day； for example； can be called out by a clock； the starting of a train announced； and the merits of a particular commodity descanted on。 All these uses are possible； but it is in a literary sense that the phonograph is more interesting。 Books can now be spoken by their authors； or a good elocutionist； and published in phonograms； which will appeal to the ear of the 'reader' instead of to his eye。 'On； four cylinders 8 inches long； with a diameter of 5；' says Edison； 'I can put the whole of NICHOLAS NICKLEBY。' To the invalid； especially； this use would come as a boon； and if the instrument were a loud speaker； a circle of listeners could be entertained。 How interesting it would be to have NICHOLAS NICKLEBY read to us in the voice of Dickens； or TAM O' SHANTER in that of Burns！ If the idea is developed； we may perhaps have circulating libraries which issue phonograms； and there is already some talk of a phonographic newspaper which will prattle politics and scandal at the breakfast…table。 Addresses； sermons； and political speeches may be delivered by the phonograph； languages taught； and dialects preserved； while the study of words cannot fail to benefit by its performance。
Musicians will now be able to record their improvisations by a phonograph placed near the instrument they are playing。 There need in fact be no more 'lost chords。' Lovers of music； like the inventor himself； will be able to purchase songs and pieces； sung and played by eminent performers； and reproduce them in their own homes。 Music… sellers will perhaps let them out； like books； and customers can choose their piece in the shop by having it rehearsed to them。
In preserving for us the words of friends who have passed away； the sound of voices which are stilled； the phonograph assumes its most beautiful and sacred character。 The Egyptians treasured in their homes the mummies of their dead。 We are able to cherish the very accents of ours； and； as it were； defeat the course of time and break the silence of the grave。 The voices of illustrious persons； heroes and statesmen； orators； actors； and singers； will go down to posterity and visit us in our homes。 A new pleasure will be added to life。 How pleasant it would be if we could listen to the cheery voice of Gordon； the playing of Liszt； or the singing of Jenny Lind！
Doubtless the rendering of the phonograph will be still further improved as time goes on ； but even now it is remarkable ； and the inventor must be considered to have redeemed his promises with regard to it。 Notwithstanding his deafness； the development of the instrument has been a labour of love to him； and those who knew his rare inventive skill believed that he would some time achieve success。 It is his favourite； his most original； and novel work。 For many triumphs of mind over matter Edison has been called the 'Napoleon of Invention；' and the aptness of the title is enhanced by his personal resemblance to the great conqueror。 But the phonograph is his victory of Austerlitz； and； like the printing…press of Gutenberg； it will assuredly immortalise his name。
'The phonograph；' said Edison of his favourite； 'is my baby； and I expect it to grow up a big fellow and support me in my old age。' Some people are still in doubt whether it will prove more than a curious plaything； but even now it seems to be coming into practical use in America； if not in Europe。
After the publication of the phonograph； Edison； owing； it is stated； to an erroneous description of the instrument by a reporter； received letters from deaf people inquiring whether it would enable them to hear well。 This； coupled with the fact that he is deaf himself； turned his thoughts to the invention of the 'megaphone；' a combination of one large speaking and two ear…trumpets； intended for carrying on a conversation beyond the ordinary range of the voicein short； a mile or two。 It is said to render a whisper audible at a distance of 1000 yards； but its very sensitiveness is a drawback； since it gathers up extraneous sounds。
To the same category belongs the 'aerophone；' which may be described as a gigantic tympanum； vibrated by a piston working in a cylinder of compressed air； which is regulated by the vibrations of the sound to be magnified。 It was designed to call out fog or other warnings in a loud and penetrating tone； but it has not been successful。
The 'magnetic ore separator' is an application of magnetism to the extraction of iron particles from powdered ores and unmagnetic matter。 The ground material is poured through a funnel or 'hopper；' and falls in a shower between the poles of a powerful electro…magnet； which draws the metal aside； thus removing it from the dress。
Among Edison's toys and minor inventions may be mentioned a 'voice mill；' or wheel driven by the vibrations of the air set up in speaking。 It consists of a tympanum or drum； having a stylus attached as in the phonograph。 When the tympanum vibrates under the influence of the voice； the stylus acts as a pawl and turns a ratchet…wheel。 An ingenious smith might apply it to the construction of a lock which would operate at the command of 'Open； Sesame！' Another trifle perhaps worthy of note is his ink； which rises on the paper and solidifies； so that a blind person can read the writing by passing his fingers over the letters。
Edison's next important work was the adaptation of the electric light for domestic illumination。 At the beginning of the century the Cornish philosopher； Humphrey Davy； had discovered that the electric current produced a brilliant arch or 'arc' of light when passed between two charcoal points drawn a little apart； and that it heated a fine rod of charcoal or a metal wire to incandescencethat is to say； a glowing condition。 A great variety of arc lamps were afterwards introduced； and Mr。 Staite； on or about the year 1844…5； invented an incandescent lamp in which the current passed through a slender stick of carbon； enclosed in a vacuum bulb of glass。 Faraday discovered that electricity could be generated by the relative motion of a magnet and a coil of wire； and hence the dynamo…electric generator； or 'dynamo；' was ere long invented and improved。
In 1878 the boulevards of Paris were lit by the arc lamps of Jablochkoff during the season of the Exhibition； and the display excited a widespread interest in the new mode of illumination。 It was too brilliant for domestic use； however； and； as the lamps were connected one after another in the same circuit like pearls upon a string； the breakage of one would interrupt the current and extinguish them all but for special precautions。 In short； the electric light was not yet 'subdivided。'
Edison； in common with others； turned his attention to the subject； and took up the neglected incandescent lamp。 He improved it by reducing the rod of carbon to a mere filament of charcoal； having a comparatively high resistance and resembling a wire in its elasticity； without being so liable to fuse under the intense heat of the current。 This he moulded into a loop； and mounted inside a pear…shaped bulb of glass。 The bulb was then exhausted of its air to prevent the oxidation of the carbon； and the whole hermetically sealed。 When a sufficient current was passed through the filament； it glowed with a dazzling lustre。 It was not too bright or powerful for a room； it produced little heat； and absolutely no fumes。 Moreover； it could be connected not in but across the main circuit of the current； and hence； if one should break； the others would continue glowing。 Edison； in short； had 'subdivided' the electric light。
In October； 1878； he telegraphed the news to London and Paris； where； owing to his g
