,,little ,,masterpieces ,,of ,,science ,illustration3 ,george ,stephenson4 ,little ,masterpieces of ,science ,edited by ,george ,iles ,,invention ,,and ,,discovery ,by ,benjamin ,franklin ,alexander ,graham ,bell ,michael ,faraday ,count ,rumford ,joseph ,henry ,george ,stephenson ,illustration ,,new ,,york ,,doubleday1 ,,page ,,company #aijb ,copyright1 #aijb1 by ,doubleday1 ,page ,co4 ,copyright1 #ahgg1 by ,george ,b4 ,prescott ,copyright1 #ahif1 by ,s4 ,s4 ,mc,clure ,co4 ,copyright1 #aijj1 by ,doubleday1 ,mc,clure ,co4 ,,preface ,to a good many of us the inventor is the true hero for he multiplies the working value of life4 ,he performs an old task with new economy1 as when he devises a mowing-machine to oust the scythe2 or he creates a service wholly new1 as when he bids a landscape depict itself on a photographic plate4 ,he1 and his twin brother1 the discoverer1 have eyes to read a lesson that ,nature has held for ages under the undiscerning gaze of other men4 ,where an ordinary observer sees1 or thinks he sees1 diversity1 a ,franklin detects identity1 as in the famous experiment here recounted which proves lightning to be one and the same with a charge of the ,leyden jar4 ,of a later day than ,franklin1 advantaged therefor by new knowledge and better opportunities for experiment1 stood ,faraday1 the founder of modern electric art4 ,his work gave the world the dynamo and motor1 the transmission of giant powers1 almost without toll1 for two hundred miles at a bound4 ,it is1 however1 in the carriage of but trifling quantities of motion1 just enough for signals1 that electricity thus far has done its most telling work4 ,among the men who have created the electric telegraph ,joseph ,henry has a commanding place4 ,a short account of what he did1 told in his own words1 is here presented4 ,then follows a narrative of the difficult task of laying the first ,atlantic cables1 a task long scouted as impossible3 it is a story which proves how much science may be indebted to unfaltering courage1 to faith in ultimate triumph4 ,to give speech the wings of electricity1 to enable friends in ,denver and ,new ,york to converse with one another1 is a marvel which only familiarity places beyond the pale of miracle4 ,shortly after he perfected the telephone ,professor ,bell described the steps which led to its construction4 ,that recital is here reprinted4 ,a recent wonder of electric art is its penetration by a photographic ray of substances until now called opaque4 ,professor ,roentgen's account of how he wrought this feat forms one of the most stirring chapters in the history of science4 ,next follows an account of the telegraph as it dispenses with metallic conductors altogether1 and trusts itself to that weightless ether which brings to the eye the luminous wave4 ,to this succeeds a chapter which considers what electricity stands for as one of the supreme resources of human wit1 a resource transcending even flame itself1 bringing articulate speech and writing to new planes of facility and usefulness4 ,it is shown that the rapidity with which during a single century electricity has been subdued for human service1 illustrates that progress has leaps as well as deliberate steps1 so that at last a gulf1 all but infinite1 divides man from his next of kin4 ,at this point we pause to recall our debt to the physical philosophy which underlies the calculations of the modern engineer4 ,in such an experiment as that of ,count ,rumford we observe how the corner-stone was laid of the knowledge that heat is motion1 and that motion under whatever guise1 as light1 electricity1 or what not1 is equally beyond creation or annihilation1 however elusively it may glide from phase to phase and vanish from view4 ,in the mastery of ,flame for the superseding of muscle1 of breeze and waterfall1 the chief credit rests with ,james ,watt1 the inventor of the steam engine4 ,beside him stands ,george ,stephenson1 who devised the locomotive which by abridging space has lengthened life and added to its highest pleasures4 ,our volume closes by narrating the competition which decided that ,stephenson's ,rocket was much superior to its rivals1 and thus opened a new chapter in the history of mankind4 ,,george ,,iles4 ,,contents ,,franklin1 ,,benjamin ,,lightning ,,identified ,,with ,,electricity ,franklin explains the action of the ,leyden phial or jar4 ,suggests lightning-rods4 ,sends a kite into the clouds during a thunderstorm2 through the kite-string obtains a spark of lightning which throws into divergence the loose fibres of the string1 just as an ordinary electrical discharge would do4 #c ,,faraday1 ,,michael ,,preparing ,,the ,,way ,,for ,,the ,,electric ,,dynamo ,,and ,,motor ,notices the inductive effect in one coil when the circuit in a concentric coil is completed or broken4 ,notices similar effects when a wire bearing a current approaches another wire or recedes from it4 ,rotates a galvanometer needle by an electric pulse4 ,induces currents in coils when the magnetism is varied in their iron or steel cores4 ,observes the lines of magnetic force as iron filings are magnetized4 ,a magnetic bar moved in and out of a coil of wire excites electricity therein1--mechanical motion is converted into electricity4 ,generates a current by spinning a copper plate in a horizontal plane4 #g ,,henry1 ,,joseph ,,invention ,,of ,,the ,,electric ,,telegraph ,improves the electro-magnet of ,sturgeon by insulating its wire with silk thread1 and by disposing the wire in several coils instead of one4 ,experiments with a large electro-magnet excited by nine distinct coils4 ,uses a battery so powerful that electro-magnets are produced one hundred times more energetic than those of ,sturgeon4 ,arranges a telegraphic circuit more than a mile long and at that distance sounds a bell by means of an electro-magnet4 #bc ,,iles1 ,,george ,,the ,,first ,,atlantic ,,cables ,forerunners at ,new ,york and ,dover4 ,gutta-percha the indispensable insulator4 ,wire is used to sheathe the cables4 ,cyrus ,w4 ,field's project for an ,atlantic cable4 ,the first cable fails4 #aheh so does the second cable #ahfe4 ,a triumph of courage1 #ahff4 ,the highway smoothed for successors4 ,lessons of the cable4 #cg ,,bell1 ,,alexander ,,graham ,,the ,,invention ,,of ,,the ,,telephone ,indebted to his father's study of the vocal organs as they form sounds4 ,examines the ,helmholtz method for the analysis and synthesis of vocal sounds4 ,suggests the electrical actuation of tuning-forks and the electrical transmission of their tones4 ,distinguishes intermittent1 pulsatory and undulatory currents4 ,devises as his first articulating telephone a harp of steel rods thrown into vibration by electro-magnetism4 ,exhibits optically the vibrations of sound1 using a preparation of a human ear3 is struck by the efficiency of a slight aural membrane4 ,attaches a bit of clock spring to a piece of goldbeater's skin1 speaks to it1 an audible message is received at a distant and similar device4 ,this contrivance improved is shown at the ,centennial ,exhibition1 ,philadelphia1 #ahgf4 ,at first the same kind of instrument transmitted and delivered1 a message2 soon two distinct instruments were invented for transmitting and for receiving4 ,extremely small magnets suffice4 ,a single blade of grass forms a telephonic circuit4 #eg ,,dam1 ,h4 ,j4 ,w4 ,,photographing ,,the ,,unseen ,roentgen indebted to the researches of ,faraday1 ,clerk-,maxwell1 ,hertz1 ,lodge and ,lenard4 ,the human optic nerve is affected by a very small range in the waves that exist in the ether4 ,beyond the visible spectrum of common light are vibrations which have long been known as heat or as photographically active4 ,crookes in a vacuous bulb produced soft light from high tension electricity4 ,lenard found that rays from a ,crookes' tube passed through substances opaque to common light4 ,roentgen extended these experiments and used the rays photographically1 taking pictures of the bones of the hand through living flesh1 and so on4 #hg ,,iles1 ,,george ,,the ,,wireless ,,telegraph ,what may follow upon electric induction4 ,telegraphy to a moving train4 ,the ,preece induction method2 its limits4 ,marconi's system4 ,his precursors1 ,hertz1 ,onesti1 ,branly and ,lodge4 ,the coherer and the vertical wire form the essence of the apparatus4 ,wireless telegraphy at sea4 #aji ,,iles1 ,,george ,,electricity1 ,,what ,,its ,,mastery ,,means3 ,,with ,a ,,review ,,and ,a ,,prospect ,electricity does all that fire ever did1 does it better1 and performs uncounted services impossible to flame4 ,its mastery means as great a forward stride as the subjugation of fire4 ,a minor invention or discovery simply adds to human resources3 a supreme conquest as of flame or electricity1 is a multiplier and lifts art and science to a new plane4 ,growth is slow1 flowering is rapid3 progress at times is so quick of pace as virtually to become a leap4 ,the mastery of electricity based on that of fire4 ,electricity vastly wider of range than heat3 it is energy in its most available and desirable phase4 ,the telegraph and the telephone contrasted with the signal fire4 ,electricity as the servant of mechanic and engineer4 ,household uses of the current4 ,electricity as an agent of research now examines ,nature in fresh aspects4 ,the investigator and the commercial exploiter render aid to one another4 ,social benefits of electricity1 in telegraphy1 in quick travel4 ,the current should serve every city house4 #abe ,,rumford1 ,,count 7,,benjamin ,,thompson7 ,,heat ,,and ,,motion ,,identified ,observes that in boring a cannon much heat is generated3 the longer the boring lasts1 the more heat is produced4 ,he argues that since heat without limit may be thus produced by motion1 heat must be motion4 #aee ,,stephenson1 ,,george ,,the ,,rocket ,,locomotive ,,and ,,its ,,victory ,shall it be a system of stationary engines or locomotives8 ,the two best practical engineers of the day are in favour of stationary engines4 ,a test of locomotives is1 however1 proffered1 and ,george ,stephenson and his son1 ,robert1 discuss how they may best build an engine to win the first prize4 ,they adopt a steam blast to stimulate the draft of the furnace1 and raise steam quickly in a boiler having twenty-five small fire-tubes of copper4 ,the ,rocket with a maximum speed of twenty-nine miles an hour distances its rivals4 ,with its load of water its weight was but four and a quarter tons4 #afc ,,invention ,,and ,,discovery ,,franklin ,,identifies ,,lightning ,,with ,,electricity ,from ,franklin's ,works1 edited in ten volumes by ,john ,bigelow1 ,vol4 ,i1 pages #bgf-bha1 copyright by ,g4 ,p4 ,putnam's ,sons1 ,new ,york4 ,dr4 ,stuber1 the author of the first continuation of ,franklin's life1 gives this account of the electrical experiments of ,franklin3-- ,his observations he communicated1 in a series of letters1 to his friend ,collinson1 the first of which is dated ,march #bh1 #agdg4 ,in these he shows the power of points in drawing and throwing off the electrical matter1 which had hitherto escaped the notice of electricians4 ,he also made the grand discovery of a plus and minus1 or of a positive and negative state of electricity4 ,we give him the honour of this without hesitation2 although the ,english have claimed it for their countryman1 ,dr4 ,watson4 ,watson's paper is dated ,january #ba1 #agdh2 ,franklin's ,july #aa1 #agdg1 several months prior4 ,shortly after ,franklin1 from his principles of the plus and minus state1 explained in a satisfactory manner the phenomena of the ,leyden phial1 first observed by ,mr4 ,cuneus1 or by ,professor ,muschenbroeck1 of ,leyden1 which had much perplexed philosophers4 ,he showed clearly that when charged the bottle contained no more electricity than before1 but that as much was taken from one side as thrown on the other2 and that to discharge it nothing was necessary but to produce a communication between the two sides by which the equilibrium might be restored1 and that then no signs of electricity would remain4 ,he afterwards demonstrated by experiments that the electricity did not reside in the coating as had been supposed1 but in the pores of the glass itself4 ,after the phial was charged he removed the coating1 and found that upon applying a new coating the shock might still be received4 ,in the year #agdi1 he first suggested his idea of explaining the phenomena of thunder gusts and of aurora borealis upon electric principles4 ,he points out many particulars in which lightning and electricity agree2 and he adduces many facts1 and reasonings from facts1 in support of his positions4 ,in the same year he conceived the astonishingly bold and grand idea of ascertaining the truth of his doctrine by actually drawing down the lightning1 by means of sharp pointed iron rods raised into the regions of the clouds4 ,even in this uncertain state his passion to be useful to mankind displayed itself in a powerful manner4 ,admitting the identity of electricity and lightning1 and knowing the power of points in repelling bodies charged with electricity1 and in conducting fires silently and imperceptibly1 he suggested the idea of securing houses1 ships and the like from being damaged by lightning1 by erecting pointed rods that should rise some feet above the most elevated part1 and descend some feet into the ground or water4 ,the effect of these he concluded would be either to prevent a stroke by repelling the cloud beyond the striking distance or by drawing off the electrical fire which it contained2 or1 if they could not effect this they would at least conduct the electrical matter to the earth without any injury to the building4 ,it was not until the summer of #ageb that he was enabled to complete his grand and unparalleled discovery by experiment4 ,the plan which he had originally proposed was1 to erect1 on some high tower or elevated place1 a sentry-box from which should rise a pointed iron rod1 insulated by being fixed in a cake of resin4 ,electrified clouds passing over this would1 he conceived1 impart to it a portion of their electricity which would be rendered evident to the senses by sparks being emitted when a key1 the knuckle1 or other conductor1 was presented to it4 ,philadelphia at this time afforded no opportunity of trying an experiment of this kind4 ,while ,franklin was waiting for the erection of a spire1 it occurred to him that he might have more ready access to the region of clouds by means of a common kite4 ,he prepared one by fastening two cross sticks to a silk handkerchief1 which would not suffer so much from the rain as paper4 ,to the upright stick was affixed an iron point4 ,the string was1 as usual1 of hemp1 except the lower end1 which was silk4 ,where the hempen string terminated1 a key was fastened4 ,with this apparatus1 on the appearance of a thundergust approaching1 he went out into the commons1 accompanied by his son1 to whom alone he communicated his intentions1 well knowing the ridicule which1 too generally for the interest of science1 awaits unsuccessful experiments in philosophy4 ,he placed himself under a shed1 to avoid the rain2 his kite was raised1 a thunder-cloud passed over it1 no sign of electricity appeared4 ,he almost despaired of success1 when suddenly he observed the loose fibres of his string to move towards an erect position4 ,he now presented his knuckle to the key and received a strong spark4 ,how exquisite must his sensations have been at this moment6 ,on his experiment depended the fate of his theory4 ,if he succeeded1 his name would rank high among those who had improved science2 if he failed1 he must inevitably be subjected to the derision of mankind1 or1 what is worse1 their pity1 as a well-meaning man1 but a weak1 silly projector4 ,the anxiety with which he looked for the result of his experiment may easily be conceived4 ,doubts and despair had begun to prevail1 when the fact was ascertained1 in so clear a manner1 that even the most incredulous could no longer withhold their assent4 ,repeated sparks were drawn from the key1 a phial was charged1 a shock given1 and all the experiments made which are usually performed with electricity4 ,,faraday',s ,,discoveries ,,leading ,,up ,,to ,,the ,,electric ,,dynamo ,,and ,,motor ,michael ,faraday was for many years ,professor of ,natural ,philosophy at the ,royal ,institution1 ,london1 where his researches did more to subdue electricity to the service of man than those of any other physicist who ever lived4 ,faraday as a ,discoverer1 by ,professor ,john ,tyndall 7his successor7 depicts a mind of the rarest ability and a character of the utmost charm4 ,this biography is published by ,d4 ,appleton ,co41 ,new ,york3 the extracts which follow are from the third chapter4 ,in #ahca we have ,faraday at the climax of his intellectual strength1 forty years of age1 stored with knowledge and full of original power4 ,through reading1 lecturing1 and experimenting1 he had become thoroughly familiar with electrical science3 he saw where light was needed and expansion possible4 ,the phenomena of ordinary electric induction belonged1 as it were1 to the alphabet of his knowledge3 he knew that under ordinary circumstances the presence of an electrified body was sufficient to excite1 by induction1 an unelectrified body4 ,he knew that the wire which carried an electric current was an electrified body1 and still that all attempts had failed to make it excite in other wires a state similar to its own4 ,what was the reason of this failure8 ,faraday never could work from the experiments of others1 however clearly described4 ,he knew well that from every experiment issues a kind of radiation1 luminous1 in different degrees to different minds1 and he hardly trusted himself to reason upon an experiment that he had not seen4 ,in the autumn of #ahca he began to repeat the experiments with electric currents1 which1 up to that time1 had produced no positive result4 ,and here1 for the sake of younger inquirers1 if not for the sake of us all1 it is worth while to dwell for a moment on a power which ,faraday possessed in an extraordinary degree4 ,he united vast strength with perfect flexibility4 ,his momentum was that of a river1 which combines weight and directness with the ability to yield to the flexures of its bed4 ,the intentness of his vision in any direction did not apparently diminish his power of perception in other directions2 and when he attacked a subject1 expecting results1 he had the faculty of keeping his mind alert1 so that results different from those which he expected should not escape him through pre-occupation4 ,he began his experiments on the induction of electric currents by composing a helix of two insulated wires1 which were wound side by side round the same wooden cylinder4 ,one of these wires he connected with a voltaic battery of ten cells1 and the other with a sensitive galvanometer4 ,when connection with the battery was made1 and while the current flowed1 no effect whatever was observed at the galvanometer4 ,but he never accepted an experimental result1 until he had applied to it the utmost power at his command4 ,he raised his battery from ten cells to one hundred and twenty cells1 but without avail4 ,the current flowed calmly through the battery wire without producing1 during its flow1 any sensible result upon the galvanometer4 ,during its flow1 and this was the time when an effect was expected--but here ,faraday's power of lateral vision1 separating1 as it were from the line of expectation1 came into play--he noticed that a feeble movement of the needle always occurred at the moment when he made contact with the battery2 that the needle would afterwards return to its former position and remain quietly there unaffected by the flowing current4 ,at the moment1 however1 when the circuit was interrupted the needle again moved1 and in a direction opposed to that observed on the completion of the circuit4 ,this result1 and others of a similar kind1 led him to the conclusion that the battery current through the one wire did in reality induce a similar current through the other2 but that it continued for an instant only1 and partook more of the nature of the electric wave from a common ,leyden jar than of the current from a voltaic battery4 ,the momentary currents thus generated were called induced currents1 while the current which generated them was called the inducing current4 ,it was immediately proved that the current generated at making the circuit was always opposed in direction to its generator1 while that developed on the rupture of the circuit coincided in direction with the inducing current4 ,it appeared as if the current on its first rush through the primary wire sought a purchase in the secondary one1 and1 by a kind of kick1 impelled backward through the latter an electric wave1 which subsided as soon as the primary current was fully established4 ,faraday1 for a time1 believed that the secondary wire1 though quiescent when the primary current had been once established1 was not in its natural condition1 its return to that condition being declared by the current observed at breaking the circuit4 ,he called this hypothetical state of the wire the electro-tonic state3 he afterwards abandoned this hypothesis1 but seemed to return to it in after life4 ,the term electro-tonic is also preserved by ,professor ,du ,bois ,reymond to express a certain electric condition of the nerves1 and ,professor ,clerk ,maxwell has ably defined and illustrated the hypothesis in the ,tenth ,volume of the ,transactions of the ,cambridge ,philosophical ,society4 ,the mere approach of a wire forming a closed curve to a second wire through which a voltaic current flowed was then shown by ,faraday to be sufficient to arouse in the neutral wire an induced current1 opposed in direction to the inducing current2 the withdrawal of the wire also generated a current having the same direction as the inducing current2 those currents existed only during the time of approach or withdrawal1 and when neither the primary nor the secondary wire was in motion1 no matter how close their proximity might be1 no induced current was generated4 ,faraday has been called a purely inductive philosopher4 ,a great deal of nonsense is1 ,i fear1 uttered in this land of ,england about induction and deduction4 ,some profess to befriend the one1 some the other1 while the real vocation of an investigator1 like ,faraday1 consists in the incessant marriage of both4 ,he was at this time full of the theory of ,ampere1 and it cannot be doubted that numbers of his experiments were executed merely to test his deductions from that theory4 ,starting from the discovery of ,oersted1 the celebrated ,french philosopher had shown that all the phenomena of magnetism then known might be reduced to the mutual attractions and repulsions of electric currents4 ,magnetism had been produced from electricity1 and ,faraday1 who all his life long entertained a strong belief in such reciprocal actions1 now attempted to effect the evolution of electricity from magnetism4 ,round a welded iron ring he placed two distinct coils of covered wire1 causing the coils to occupy opposite halves of the ring4 ,connecting the ends of one of the coils with a galvanometer1 he found that the moment the ring was magnetized1 by sending a current through the other coil1 the galvanometer needle whirled round four or five times in succession4 ,the action1 as before1 was that of a pulse1 which vanished immediately4 ,on interrupting the current1 a whirl of the needle in the opposite direction occurred4 ,it was only during the time of magnetization or demagnetization that these effects were produced4 ,the induced currents declared a change of condition only1 and they vanished the moment the act of magnetization or demagnetization was complete4 ,the effects obtained with the welded ring were also obtained with straight bars of iron4 ,whether the bars were magnetized by the electric current1 or were excited by the contact of permanent steel magnets1 induced currents were always generated during the rise1 and during the subsidence of the magnetism4 ,the use of iron was then abandoned1 and the same effects were obtained by merely thrusting a permanent steel magnet into a coil of wire4 ,a rush of electricity through the coil accompanied the insertion of the magnet2 an equal rush in the opposite direction accompanied its withdrawal4 ,the precision with which ,faraday describes these results1 and the completeness with which he defined the boundaries of his facts1 are wonderful4 ,the magnet1 for example1 must not be passed quite through the coil1 but only half through1 for if passed wholly through1 the needle is stopped as by a blow1 and then he shows how this blow results from a reversal of the electric wave in the helix4 ,he next operated with the powerful permanent magnet of the ,royal ,society1 and obtained with it1 in an exalted degree1 all the foregoing phenomena4 ,and now he turned the light of these discoveries upon the darkest physical phenomenon of that day4 ,arago had discovered in #ahbd1 that a disk of non-magnetic metal had the power of bringing a vibrating magnetic needle suspended over it rapidly to rest2 and that on causing the disk to rotate the magnetic needle rotated along with it4 ,when both were quiescent1 there was not the slightest measurable attraction or repulsion exerted between the needle and the disk2 still when in motion the disk was competent to drag after it1 not only a light needle1 but a heavy magnet4 ,the question had been probed and investigated with admirable skill by both ,arago and ,ampere1 and ,poisson had published a theoretic memoir on the subject2 but no cause could be assigned for so extraordinary an action4 ,it had also been examined in this country by two celebrated men1 ,mr4 ,babbage and ,sir ,john ,herschel2 but it still remained a mystery4 ,faraday always recommended the suspension of judgment in cases of doubt4 ,i have always admired1 he says1 the prudence and philosophical reserve shown by ,m4 ,arago in resisting the temptations to give a theory of the effect he had discovered1 so long as he could not devise one which was perfect in its application1 and in refusing to assent to the imperfect theories of others4 ,now1 however1 the time for theory had come4 ,faraday saw mentally the rotating disk1 under the operation of the magnet1 flooded with his induced currents1 and from the known laws of interaction between currents and magnets he hoped to deduce the motion observed by ,arago4 ,that hope he realized1 showing by actual experiment that when his disk rotated currents passed through it1 their position and direction being such as must1 in accordance with the established laws of electro-magnetic action1 produce the observed rotation4 ,introducing the edge of his disk between the poles of the large horseshoe magnet of the ,royal ,society1 and connecting the axis and the edge of the disk1 each by a wire with a galvanometer1 he obtained1 when the disk was turned round1 a constant flow of electricity4 ,the direction of the current was determined by the direction of the motion1 the current being reversed when the rotation was reversed4 ,he now states the law which rules the production of currents in both disks and wires1 and in so doing uses1 for the first time1 a phrase which has since become famous4 ,when iron filings are scattered over a magnet1 the particles of iron arrange themselves in certain determined lines called magnetic curves4 ,in #ahca1 ,faraday for the first time called these curves lines of magnetic force2 and he showed that to produce induced currents neither approach to nor withdrawal from a magnetic source1 or centre1 or pole1 was essential1 but that it was only necessary to cut appropriately the lines of magnetic force4 ,faraday's first paper on ,magneto-electric ,induction1 which ,i have here endeavoured to condense1 was read before the ,royal ,society on the #bdth of ,november1 #ahca4 ,on ,january #ab1 #ahcb1 he communicated to the ,royal ,society a second paper on ,terrestrial ,magneto-electric ,induction1 which was chosen as the ,bakerian ,lecture for the year4 ,he placed a bar of iron in a coil of wire1 and lifting the bar into the direction of the dipping needle1 he excited by this action a current in the coil4 ,on reversing the bar1 a current in the opposite direction rushed through the wire4 ,the same effect was produced1 when1 on holding the helix in the line of dip1 a bar of iron was thrust into it4 ,here1 however1 the earth acted on the coil through the intermediation of the bar of iron4 ,he abandoned the bar and simply set a copper-plate spinning in a horizontal plane2 he knew that the earth's lines of magnetic force then crossed the plate at an angle of about #gj deg44 ,when the plate spun round1 the lines of force were intersected and induced currents generated1 which produced their proper effect when carried from the plate to the galvanometer4 ,when the plate was in the magnetic meridian1 or in any other plane coinciding with the magnetic dip1 then its rotation produced no effect upon the galvanometer4 ,at the suggestion of a mind fruitful in suggestions of a profound and philosophic character--,i mean that of ,sir ,john ,herschel--,mr4 ,barlow1 of ,woolwich1 had experimented with a rotating iron shell4 ,mr4 ,christie had also performed an elaborate series of experiments on a rotating iron disk4 ,both of them had found that when in rotation the body exercised a peculiar action upon the magnetic needle1 deflecting it in a manner which was not observed during quiescence2 but neither of them was aware at the time of the agent which produced this extraordinary deflection4 ,they ascribed it to some change in the magnetism of the iron shell and disk4 ,but ,faraday at once saw that his induced currents must come into play here1 and he immediately obtained them from an iron disk4 ,with a hollow brass ball1 moreover1 he produced the effects obtained by ,mr4 ,barlow4 ,iron was in no way necessary3 the only condition of success was that the rotating body should be of a character to admit of the formation of currents in its substance3 it must1 in other words1 be a conductor of electricity4 ,the higher the conducting power the more copious were the currents4 ,he now passes from his little brass globe to the globe of the earth4 ,he plays like a magician with the earth's magnetism4 ,he sees the invisible lines along which its magnetic action is exerted and sweeping his wand across these lines evokes this new power4 ,placing a simple loop of wire round a magnetic needle he bends its upper portion to the west3 the north pole of the needle immediately swerves to the east3 he bends his loop to the east1 and the north poles moves to the west4 ,suspending a common bar magnet in a vertical position1 he causes it to spin round its own axis4 ,its pole being connected with one end of a galvanometer wire1 and its equator with the other end1 electricity rushes round the galvanometer from the rotating magnet4 ,he remarks upon the singular independence of the magnetism and the body of the magnet which carries it4 ,the steel behaves as if it were isolated from its own magnetism4 ,and then his thoughts suddenly widen1 and he asks himself whether the rotating earth does not generate induced currents as it turns round its axis from west to east4 ,in his experiment with the twirling magnet the galvanometer wire remained at rest2 one portion of the circuit was in motion relatively to another portion4 ,but in the case of the twirling planet the galvanometer wire would necessarily be carried along with the earth2 there would be no relative motion4 ,what must be the consequence8 ,take the case of a telegraph wire with its two terminal plates dipped into the earth1 and suppose the wire to lie in the magnetic meridian4 ,the ground underneath the wire is influenced like the wire itself by the earth's rotation2 if a current from south to north be generated in the wire1 a similar current from south to north would be generated in the earth under the wire2 these currents would run against the same terminal plates1 and thus neutralize each other4 ,this inference appears inevitable1 but his profound vision perceived its possible invalidity4 ,he saw that it was at least possible that the difference of conducting power between the earth and the wire might give one an advantage over the other1 and that thus a residual or differential current might be obtained4 ,he combined wires of different materials1 and caused them to act in opposition to each other1 but found the combination ineffectual4 ,the more copious flow in the better conductor was exactly counterbalanced by the resistance of the worst4 ,still1 though experiment was thus emphatic1 he would clear his mind of all discomfort by operating on the earth itself4 ,he went to the round lake near ,kensington ,palace1 and stretched four hundred and eighty feet of copper wire1 north and south1 over the lake1 causing plates soldered to the wire at its ends to dip into the water4 ,the copper wire was severed at the middle1 and the severed ends connected with a galvanometer4 ,no effect whatever was observed4 ,but though quiescent water gave no effect1 moving water might4 ,he therefore worked at ,london ,bridge for three days during the ebb and flow of the tide1 but without any satisfactory result4 ,still he urges1 ,theoretically it seems a necessary consequence1 that where water is flowing there electric currents should be formed4 ,if a line be imagined passing from ,dover to ,calais through the sea1 and returning through the land1 beneath the water1 to ,dover1 it traces out a circuit of conducting matter one part of which1 when the water moves up or down the channel1 is cutting the magnetic curves of the earth1 while the other is relatively at rest4444 ,there is every reason to believe that currents do run in the general direction of the circuit described1 either one way or the other1 according as the passage of the waters is up or down the channel4 ,this was written before the submarine cable was thought of1 and he once informed me that actual observation upon that cable had been found to be in accordance with his theoretic deduction4 ,three years subsequent to the publication of these researches1 that is to say on ,january #bi1 #ahce1 ,faraday read before the ,royal ,society a paper ,on the influence by induction of an electric current upon itself4 ,a shock and spark of a peculiar character had been observed by a young man named ,william ,jenkin1 who must have been a youth of some scientific promise1 but who1 as ,faraday once informed me1 was dissuaded by his own father from having anything to do with science4 ,the investigation of the fact noticed by ,mr4 ,jenkin led ,faraday to the discovery of the extra current1 or the current induced in the primary wire itself at the moments of making and breaking contact1 the phenomena of which he described and illustrated in the beautiful and exhaustive paper referred to4 ,seven and thirty years have passed since the discovery of magneto-electricity2 but1 if we except the extra current1 until quite recently nothing of moment was added to the subject4 ,faraday entertained the opinion that the discoverer of a great law or principle had a right to the spoils--this was his term--arising from its illustration2 and guided by the principle he had discovered1 his wonderful mind1 aided by his wonderful ten fingers1 overran in a single autumn this vast domain1 and hardly left behind him the shred of a fact to be gathered by his successors4 ,and here the question may arise in some minds1 ,what is the use of it all8 ,the answer is1 that if man's intellectual nature thirsts for knowledge then knowledge is useful because it satisfies this thirst4 ,if you demand practical ends1 you must1 ,i think1 expand your definition of the term practical1 and make it include all that elevates and enlightens the intellect1 as well as all that ministers to the bodily health and comfort of men4 ,still1 if needed1 an answer of another kind might be given to the question what is its use8 ,as far as electricity has been applied for medical purposes1 it has been almost exclusively ,faraday's electricity4 ,you have noticed those lines of wire which cross the streets of ,london4 ,it is ,faraday's currents that speed from place to place through these wires4 ,approaching the point of ,dungeness1 the mariner sees an unusually brilliant light1 and from the noble lighthouse of ,la ,heve the same light flashes across the sea4 ,these are ,faraday's sparks exalted by suitable machinery to sun-like splendour4 ,at the present moment the ,board of ,trade and the ,brethren of the ,trinity ,house1 as well as the ,commissioners of ,northern ,lights1 are contemplating the introduction of the ,magneto-electric ,light at numerous points upon our coasts2 and future generations will be able to refer to those guiding stars in answer to the question1 what has been the practical use of the labours of ,faraday8 ,but ,i would again emphatically say1 that his work needs no justification1 and that if he had allowed his vision to be disturbed by considerations regarding the practical use of his discoveries1 those discoveries would never have been made by him4 ,i have rather1 he writes in #ahca1 been desirous of discovering new facts and new relations dependent on magneto-electric induction1 than of exalting the force of those already obtained2 being assured that the latter would find their full development hereafter4 ,in #ahag1 when lecturing before a private society in ,london on the element chlorine1 ,faraday thus expresses himself with reference to this question of utility4 ,before leaving this subject1 ,i will point out the history of this substance as an answer to those who are in the habit of saying to every new fact1 ',what is its use8' ,dr4 ,franklin says to such1 ',what is the use of an infant8' ,the answer of the experimentalist is1 ',endeavour to make it useful4' ,when ,scheele discovered this substance1 it appeared to have no use2 it was in its infancy and useless state1 but having grown up to maturity1 witness its powers1 and see what endeavours to make it useful have done4 ,,professor ,,joseph ,,henry',s ,,invention ,,of ,,the ,,electric ,,telegraph ,in #ahee the ,regents of the ,smithsonian ,institution1 ,washington1 ,d4 ,c41 at the instance of their secretary1 ,professor ,joseph ,henry1 took evidence with respect to his claims as inventor of the electric telegraph4 ,the essential paragraphs of ,professor ,henry's statement are taken from the ,proceedings of the ,board of ,regents of the ,smithsonian ,institution1 ,washington1 #aheg4 ,there are several forms of the electric telegraph2 first1 that in which frictional electricity has been proposed to produce sparks and motion of pith balls at a distance4 ,second1 that in which galvanism has been employed to produce signals by means of bubbles of gas from the decomposition of water4 ,third1 that in which electro-magnetism is the motive power to produce motion at a distance2 and again1 of the latter there are two kinds of telegraphs1 those in which the intelligence is indicated by the motion of a magnetic needle1 and those in which sounds and permanent signs are made by the attraction of an electro-magnet4 ,the latter is the class to which ,mr4 ,morse's invention belongs4 ,the following is a brief exposition of the several steps which led to this form of the telegraph4 ,the first essential fact which rendered the electro-magnetic telegraph possible was discovered by ,oersted1 in the winter of #ahai-'bj4 ,it is illustrated by figure #a1 in which the magnetic needle is deflected by the action of a current of galvanism transmitted through the wire ,a ,b4 ,illustration3 ,fig4 #a ,the second fact of importance1 discovered in #ahbj1 by ,arago and ,davy1 is illustrated in ,fig4 #b4 ,it consists in this1 that while a current of galvanism is passing through a copper wire ,a ,b1 it is magnetic1 it attracts iron filings and not those of copper or brass1 and is capable of developing magnetism in soft iron4 ,illustration3 ,fig4 #b ,the next important discovery1 also made in #ahbj1 by ,ampere1 was that two wires through which galvanic currents are passing in the same direction attract1 and in the opposite direction1 repel1 each other4 ,on this fact ,ampere founded his celebrated theory1 that magnetism consists merely in the attraction of electrical currents revolving at right angles to the line joining the two poles of the magnet4 ,the magnetization of a bar of steel or iron1 according to this theory consists in establishing within the metal by induction a series of electrical currents1 all revolving in the same direction at right angles to the axis or length of the bar4 ,illustration3 ,fig4 #c ,it was this theory which led ,arago1 as he states1 to adopt the method of magnetizing sewing needles and pieces of steel wire1 shown in ,fig4 #c4 ,this method consists in transmitting a current of electricity through a helix surrounding the needle or wire to be magnetised4 ,for the purpose of insulation the needle was enclosed in a glass tube1 and the several turns of the helix were at a distance from each other to insure the passage of electricity through the whole length of the wire1 or1 in other words1 to prevent it from seeking a shorter passage by cutting across from one spire to another4 ,the helix employed by ,arago obviously approximates the arrangement required by the theory of ,ampere1 in order to develop by induction the magnetism of the iron4 ,by an attentive perusal of the original account of the experiments of ,arago1 it will be seen that1 properly speaking1 he made no electro-magnet1 as has been asserted by ,morse and others2 his experiments were confined to the magnetism of iron filings1 to sewing needles and pieces of steel wire of the diameter of a millimetre1 or of about the thickness of a small knitting needle4 ,illustration3 ,fig4 #d ,mr4 ,sturgeon1 in #ahbe1 made an important step in advance of the experiments of ,arago1 and produced what is properly known as the electro-magnet4 ,he bent a piece of iron wire into the form of a horseshoe1 covered it with varnish to insulate it1 and surrounded it with a helix1 of which the spires were at a distance4 ,when a current of galvanism was passed through the helix from a small battery of a single cup the iron wire became magnetic1 and continued so during the passage of the current4 ,when the current was interrupted the magnetism disappeared1 and thus was produced the first temporary soft iron magnet4 ,the electro-magnet of ,sturgeon is shown in ,fig4 #d4 ,by comparing ,figs4 #c and #d it will be seen that the helix employed by ,sturgeon was of the same kind as that used by ,arago2 instead however1 of a straight steel wire inclosed in a tube of glass1 the former employed a bent wire of soft iron4 ,the difference in the arrangement at first sight might appear to be small1 but the difference in the results produced was important1 since the temporary magnetism developed in the arrangement of ,sturgeon was sufficient to support a weight of several pounds1 and an instrument was thus produced of value in future research4 ,illustration3 ,fig4 #e ,the next improvement was made by myself4 ,after reading an account of the galvanometer of ,schweigger1 the idea occurred to me that a much nearer approximation to the requirements of the theory of ,ampere could be attained by insulating the conducting wire itself1 instead of the rod to be magnetized1 and by covering the whole surface of the iron with a series of coils in close contact4 ,this was effected by insulating a long wire with silk thread1 and winding this around the rod of iron in close coils from one end to the other4 ,the same principle was extended by employing a still longer insulated wire1 and winding several strata of this over the first1 care being taken to insure the insulation between each stratum by a covering of silk ribbon4 ,by this arrangement the rod was surrounded by a compound helix formed of a long wire of many coils1 instead of a single helix of a few coils1 7,fig4 #e74 ,in the arrangement of ,arago and ,sturgeon the several turns of wire were not precisely at right angles to the axis of the rod1 as they should be1 to produce the effect required by the theory1 but slightly oblique1 and therefore each tended to develop a separate magnetism not coincident with the axis of the bar4 ,but in winding the wire over itself1 the obliquity of the several turns compensated each other1 and the resultant action was at right angles to the bar4 ,the arrangement then introduced by myself was superior to those of ,arago and ,sturgeon1 first in the greater multiplicity of turns of wire1 and second in the better application of these turns to the development of magnetism4 ,the power of the instrument with the same amount of galvanic force1 was by this arrangement several times increased4 ,the maximum effect1 however1 with this arrangement and a single battery was not yet obtained4 ,after a certain length of wire had been coiled upon the iron1 the power diminished with a further increase of the number of turns4 ,this was due to the increased resistance which the longer wire offered to the conduction of electricity4 ,two methods of improvement therefore suggested themselves4 ,the first consisted1 not in increasing the length of the coil1 but in using a number of separate coils on the same piece of iron4 ,by this arrangement the resistance to the conduction of the electricity was diminished and a greater quantity made to circulate around the iron from the same battery4 ,the second method of producing a similar result consisted in increasing the number of elements of the battery1 or1 in other words1 the projectile force of the electricity1 which enabled it to pass through an increased number of turns of wire1 and thus1 by increasing the length of the wire1 to develop the maximum power of the iron4 ,illustration3 ,fig4 #f ,to test these principles on a larger scale1 the experimental magnet was constructed1 which is shown in ,fig4 #f4 ,in this a number of compound helices were placed on the same bar1 their ends left projecting1 and so numbered that they could be all united into one long helix1 or variously combined in sets of lesser length4 ,from a series of experiments with this and other magnets it was proved that1 in order to produce the greatest amount of magnetism from a battery of a single cup1 a number of helices is required2 but when a compound battery is used1 then one long wire must be employed1 making many turns around the iron1 the length of wire and consequently the number of turns being commensurate with the projectile power of the battery4 ,in describing the results of my experiments1 the terms intensity and quantity magnets were introduced to avoid circumlocution1 and were intended to be used merely in a technical sense4 ,by the intensity magnet ,i designated a piece of soft iron1 so surrounded with wire that its magnetic power could be called into operation by an intensity battery1 and by a quantity magnet1 a piece of iron so surrounded by a number of separate coils1 that its magnetism could be fully developed by a quantity battery4 ,i was the first to point out this connection of the two kinds of the battery with the two forms of the magnet1 in my paper in ,silliman's ,journal1 ,january1 #ahca1 and clearly to state that when magnetism was to be developed by means of a compound battery1 one long coil was to be employed1 and when the maximum effect was to be produced by a single battery1 a number of single strands were to be used4 ,these steps in the advance of electro-magnetism1 though small1 were such as to interest and astonish the scientific world4 ,with the same battery used by ,mr4 ,sturgeon1 at least a hundred times more magnetism was produced than could have been obtained by his experiment4 ,the developments were considered at the time of much importance in a scientific point of view1 and they subsequently furnished the means by which magneto-electricity1 the phenomena of dia-magnetism1 and the magnetic effects on polarized light were discovered4 ,they gave rise to the various forms of electro-magnetic machines which have since exercised the ingenuity of inventors in every part of the world1 and were of immediate applicability in the introduction of the magnet to telegraphic purposes4 ,neither the electro-magnet of ,sturgeon nor any electro-magnet ever made previous to my investigations was applicable to transmitting power to a distance4 ,the principles ,i have developed were properly appreciated by the scientific mind of ,dr4 ,gale1 and applied by him to operate ,mr4 ,morse's machine at a distance4 ,previous to my investigations the means of developing magnetism in soft iron were imperfectly understood4 ,the electro-magnet made by ,sturgeon1 and copied by ,dana1 of ,new ,york1 was an imperfect quantity magnet1 the feeble power of which was developed by a single battery4 ,it was entirely inapplicable to a long circuit with an intensity battery1 and no person possessing the requisite scientific knowledge1 would have attempted to use it in that connection after reading my paper4 ,in sending a message to a distance1 two circuits are employed1 the first a long circuit through which the electricity is sent to the distant station to bring into action the second1 a short one1 in which is the local battery and magnet for working the machine4 ,in order to give projectile force sufficient to send the power to a distance1 it is necessary to use an intensity battery in the long circuit1 and in connection with this1 at the distant station1 a magnet surrounded with many turns of one long wire must be employed to receive and multiply the effect of the current enfeebled by its transmission through the long conductor4 ,in the local or short circuit either an intensity or a quantity magnet may be employed4 ,if the first be used1 then with it a compound battery will be required2 and1 therefore on account of the increased resistance due to the greater quantity of acid1 a less amount of work will be performed by a given amount of material2 and1 consequently1 though this arrangement is practicable it is by no means economical4 ,in my original paper ,i state that the advantages of a greater conducting power1 from using several wires in the quantity magnet1 may1 in a less degree1 be obtained by substituting for them one large wire2 but in this case1 on account of the greater obliquity of the spires and other causes1 the magnetic effect would be less4 ,in accordance with these principles1 the receiving magnet1 or that which is introduced into the long circuit1 consists of a horseshoe magnet surrounded with many hundred turns of a single long wire1 and is operated with a battery of from twelve to twenty-four elements or more1 while in the local circuit it is customary to employ a battery of one or two elements with a much thicker wire and fewer turns4 ,it will1 ,i think1 be evident to the impartial reader that these were improvements in the electro-magnet1 which first rendered it adequate to the transmission of mechanical power to a distance2 and had ,i omitted all allusion to the telegraph in my paper1 the conscientious historian of science would have awarded me some credit1 however small might have been the advance which ,i made4 ,arago and ,sturgeon1 in the accounts of their experiments1 make no mention of the telegraph1 and yet their names always have been and will be associated with the invention4 ,i briefly1 however1 called attention to the fact of the applicability of my experiments to the construction of the telegraph2 but not being familiar with the history of the attempts made in regard to this invention1 ,i called it ,barlow's project1 while ,i ought to have stated that ,mr4 ,barlow's investigation merely tended to disprove the possibility of a telegraph4 ,i did not refer exclusively to the needle telegraph when1 in my paper1 ,i stated that the magnetic action of a current from a trough is at least not sensibly diminished by passing through a long wire4 ,this is evident from the fact that the immediate experiment from which this deduction was made was by means of an electro-magnet and not by means of a needle galvanometer4 ,illustration3 ,fig4 #g ,at the conclusion of the series of experiments which ,i described in ,silliman's ,journal1 there were two applications of the electro-magnet in my mind3 one the production of a machine to be moved by electro-magnetism1 and the other the transmission of or calling into action power at a distance4 ,the first was carried into execution in the construction of the machine described in ,silliman's ,journal1 vol4 xx1 #ahca1 and for the purpose of experimenting in regard to the second1 ,i arranged around one of the upper rooms in the ,albany ,academy a wire of more than a mile in length1 through which ,i was enabled to make signals by sounding a bell1 7,fig4 #g47 ,the mechanical arrangement for effecting this object was simply a steel bar1 permanently magnetized1 of about ten inches in length1 supported on a pivot1 and placed with its north end between the two arms of a horseshoe magnet4 ,when the latter was excited by the current1 the end of the bar thus placed was attracted by one arm of the horseshoe1 and repelled by the other1 and was thus caused to move in a horizontal plane and its further extremity to strike a bell suitably adjusted4 ,i also devised a method of breaking a circuit1 and thereby causing a large weight to fall4 ,it was intended to illustrate the practicability of calling into action a great power at a distance capable of producing mechanical effects2 but as a description of this was not printed1 ,i do not place it in the same category with the experiments of which ,i published an account1 or the facts which could be immediately deduced from my papers in ,silliman's ,journal4 ,from a careful investigation of the history of electro-magnetism in its connection with the telegraph1 the following facts may be established3 #a4 ,previous to my investigations the means of developing magnetism in soft iron were imperfectly understood1 and the electro-magnet which then existed was inapplicable to the transmission of power to a distance4 #b4 ,i was the first to prove by actual experiment that1 in order to develop magnetic power at a distance1 a galvanic battery of intensity must be employed to project the current through the long conductor1 and that a magnet surrounded by many turns of one long wire must be used to receive this current4 #c4 ,i was the first actually to magnetize a piece of iron at a distance1 and to call attention to the fact of the applicability of my experiments to the telegraph4 #d4 ,i was the first to actually sound a bell at a distance by means of the electro-magnet4 #e4 ,the principles ,i had developed were applied by ,dr4 ,gale to render ,morse's machine effective at a distance4 ,,the ,,first ,,atlantic ,,cables ,,george ,,iles ,from ,flame1 ,electricity and the ,camera1 copyright ,doubleday1 ,page ,co41 ,new ,york4 ,electric telegraphy on land has put a vast distance between itself and the mechanical signalling of ,chappe1 just as the scope and availability of the ,french invention are in high contrast with the rude signal fires of the primitive savage4 ,as the first land telegraphs joined village to village1 and city to city1 the crossing of water came in as a minor incident2 the wires were readily committed to the bridges which spanned streams of moderate width4 ,where a river or inlet was unbridged1 or a channel was too wide for the roadway of the engineer1 the question arose1 ,may we lay an electric wire under water8 ,with an ordinary land line1 air serves as so good a non-conductor and insulator that as a rule cheap iron may be employed for the wire instead of expensive copper4 ,in the quest for non-conductors suitable for immersion in rivers1 channels1 and the sea1 obstacles of a stubborn kind were confronted4 ,to overcome them demanded new materials1 more refined instruments1 and a complete revision of electrical philosophy4 ,as far back as #agie1 ,francisco ,salva had recommended to the ,academy of ,sciences1 ,barcelona1 the covering of subaqueous wires by resin1 which is both impenetrable by water and a non-conductor of electricity4 ,insulators1 indeed1 of one kind and another1 were common enough1 but each of them was defective in some quality indispensable for success4 ,neither glass nor porcelain is flexible1 and therefore to lay a continuous line of one or the other was out of the question4 ,resin and pitch were even more faulty1 because extremely brittle and friable4 ,what of such fibres as hemp or silk1 if saturated with tar or some other good non-conductor8 ,for very short distances under still water they served fairly well1 but any exposure to a rocky beach with its chafing action1 any rub by a passing anchor1 was fatal to them4 ,what the copper wire needed was a covering impervious to water1 unchangeable in composition by time1 tough of texture1 and non-conducting in the highest degree4 ,fortunately all these properties are united in gutta-percha3 they exist in nothing else known to art4 ,gutta-percha is the hardened juice of a large tree 7,isonandra gutta7 common in the ,malay ,archipelago2 it is tough and strong1 easily moulded when moderately heated4 ,in comparison with copper it is but one #fj1jjj1jjj1jjj1jjj1jjj1jjjth as conductive4 ,as without gutta-percha there could be no ocean telegraphy1 it is worth while recalling how it came within the purview of the electrical engineer4 ,in #ahdc ,jose d',almeida1 a ,portuguese engineer1 presented to the ,royal ,asiatic ,society1 ,london1 the first specimens of gutta-percha brought to ,europe4 ,a few months later1 ,dr4 ,w4 ,montgomerie1 a surgeon1 gave other specimens to the ,society of ,arts1 of ,london1 which exhibited them2 but it was four years before the chief characteristic of the gum was recognized4 ,in #ahdg ,mr4 ,s4 ,t4 ,armstrong of ,new ,york1 during a visit to ,london1 inspected a pound or two of gutta-percha1 and found it to be twice as good a non-conductor as glass4 ,the next year1 through his instrumentality1 a cable covered with this new insulator was laid between ,new ,york and ,jersey ,city2 its success prompted ,mr ,armstrong to suggest that a similarly protected cable be submerged between ,america and ,europe4 ,eighteen years of untiring effort1 impeded by the errors inevitable to the pioneer1 stood between the proposal and its fulfilment4 ,in #ahdh the ,messrs4 ,siemens laid under water in the port of ,kiel a wire covered with seamless gutta-percha1 such as1 beginning with #ahdg1 they had employed for subterranean conductors4 ,this particular wire was not used for telegraphy1 but formed part of a submarine-mine system4 ,in #ahdi ,mr4 ,c4 ,v4 ,walker laid an experimental line in the ,english ,channel2 he proved the possibility of signalling for two miles through a wire covered with gutta-percha1 and so prepared the way for a venture which joined the shores of ,france and ,england4 ,illustration3 ,fig4 #eh4--;,calais-,dover cable1 #ahea ,in #ahej a cable twenty-five miles in length was laid from ,dover to ,calais1 only to prove worthless from faulty insulation and the lack of armour against dragging anchors and fretting rocks4 ,in #ahea the experiment was repeated with success4 ,the conductor now was not a single wire of copper1 but four wires1 wound spirally1 so as to combine strength with flexibility2 these were covered with gutta-percha and surrounded with tarred hemp4 ,as a means of imparting additional strength1 ten iron wires were wound round the hemp--a feature which has been copied in every subsequent cable 7,fig4 #eh74 ,the engineers were fast learning the rigorous conditions of submarine telegraphy2 in its essentials the ,dover-,calais line continues to be the type of deep-sea cables to-day4 ,the success of the wire laid across the ,british ,channel incited other ventures of the kind4 ,many of them1 through careless construction or unskilful laying1 were utter failures4 ,at last1 in #ahee1 a submarine line #aga miles in length gave excellent service1 as it united ,varna with ,constantinople2 this was the greatest length of satisfactory cable until the submergence of an ,atlantic line4 ,in #ahed ,cyrus ,w4 ,field of ,new ,york opened a new chapter in electrical enterprise as he resolved to lay a cable between ,ireland and ,newfoundland1 along the shortest line that joins ,europe to ,america4 ,he chose ,valentia and ,heart's ,content1 a little more than #a1fjj miles apart1 as his termini1 and at once began to enlist the co-operation of his friends4 ,although an unfaltering enthusiast when once his great idea had possession of him1 ,mr4 ,field was a man of strong common sense4 ,from first to last he went upon well-ascertained facts2 when he failed he did so simply because other facts1 which he could not possibly know1 had to be disclosed by costly experience4 ,messrs4 ,whitehouse and ,bright1 electricians to his company1 were instructed to begin a preliminary series of experiments4 ,they united a continuous stretch of wires laid beneath land and water for a distance of #b1jjj miles1 and found that through this extraordinary circuit they could transmit as many as four signals per second4 ,they inferred that an ,atlantic cable would offer but little more resistance1 and would therefore be electrically workable and commercially lucrative4 ,in #aheg a cable was forthwith manufactured1 divided in halves1 and stowed in the holds of the ,niagara of the ,united ,states navy1 and the ,agamemnon of the ,british fleet4 ,the ,niagara sailed from ,ireland2 the sister ship proceeded to ,newfoundland1 and was to meet her in mid-ocean4 ,when the ,niagara had run out #cce miles of her cable it snapped under a sudden increase of strain at the paying-out machinery2 all attempts at recovery were unavailing1 and the work for that year was abandoned4 ,the next year it was resumed1 a liberal supply of new cable having been manufactured to replace the lost section1 and to meet any fresh emergency that might arise4 ,a new plan of voyages was adopted3 the vessels now sailed together to mid-sea1 uniting there both portions of the cable2 then one ship steamed off to ,ireland1 the other to the ,newfoundland coast4 ,both reached their destinations on the same day1 ,august #e1 #aheh1 and1 feeble and irregular though it was1 an electric pulse for the first time now bore a message from hemisphere to hemisphere4 ,after #gcb despatches had passed through the wire it became silent forever4 ,in one of these despatches from ,london1 the ,war ,office countermanded the departure of two regiments about to leave ,canada for ,england1 which saved an outlay of about #bej1jjj4 ,this widely quoted fact demonstrated with telling effect the value of cable telegraphy4 ,now followed years of struggle which would have dismayed any less resolute soul than ,mr4 ,field4 ,the ,civil ,war had broken out1 with its perils to the ,union1 its alarms and anxieties for every ,american heart4 ,but while battleships and cruisers were patrolling the coast from ,maine to ,florida1 and regiments were marching through ,washington on their way to battle1 there was no remission of effort on the part of the great projector4 ,indeed1 in the misunderstandings which grew out of the war1 and that at one time threatened international conflict1 he plainly saw how a cable would have been a peace-maker4 ,a single word of explanation through its wire1 and angry feelings on both sides of the ocean would have been allayed at the time of the ,trent affair4 ,in this conviction he was confirmed by the ,english press2 the ,london ,times said3 ,we nearly went to war with ,america because we had no telegraph across the ,atlantic4 ,in #ahei the ,british government had appointed a committee of eminent engineers to inquire into the feasibility of an ,atlantic telegraph1 with a view to ascertaining what was wanting for success1 and with the intention of adding to its original aid in case the enterprise were revived4 ,in ,july1 #ahfc1 this committee presented a report entirely favourable in its terms1 affirming that a well-insulated cable1 properly protected1 of suitable specific gravity1 made with care1 tested under water throughout its progress with the best-known apparatus1 and paid into the ocean with the most improved machinery1 possesses every prospect of not only being successfully laid in the first instance1 but may reasonably be relied upon to continue for many years in an efficient state for the transmission of signals4 ,taking his stand upon this endorsement1 ,mr4 ,field now addressed himself to the task of raising the large sum needed to make and lay a new cable which should be so much better than the old ones as to reward its owners with triumph4 ,he found his ,english friends willing to venture the capital required1 and without further delay the manufacture of a new cable was taken in hand4 ,in every detail the recommendations of the ,scientific ,committee were carried out to the letter1 so that the cable of #ahfe was incomparably superior to that of #aheh4 ,first1 the central copper wire1 which was the nerve along which the lightning was to run1 was nearly three times larger than before4 ,the old conductor was a strand consisting of seven fine wires1 six laid around one1 and weighed but #ajg pounds to the mile4 ,the new was composed of the same number of wires1 but weighed #cjj pounds to the mile4 ,it was made of the finest copper obtainable4 ,to secure insulation1 this conductor was first embedded in ,chatterton's compound1 a preparation impervious to water1 and then covered with four layers of gutta-percha1 which were laid on alternately with four thin layers of ,chatterton's compound4 ,the old cable had but three coatings of gutta-percha1 with nothing between4 ,its entire insulation weighed but #bfa pounds to the mile1 while that of the new weighed #djj pounds4#a ,the exterior wires1 ten in number1 were of ,bessemer steel1 each separately wound in pitch-soaked hemp yarn1 the shore ends specially protected by thirty-six wires girdling the whole4 ,here was a combination of the tenacity of steel with much of the flexibility of rope4 ,the insulation of the copper was so excellent as to exceed by a hundredfold that of the core of #aheh--which1 faulty though it was1 had1 nevertheless1 sufficed for signals4 ,so much inconvenience and risk had been encountered in dividing the task of cable-laying between two ships that this time it was decided to charter a single vessel1 the ,great ,eastern1 which1 fortunately1 was large enough to accommodate the cable in an unbroken length4 ,foilhommerum ,bay1 about six miles from ,valentia1 was selected as the new ,irish terminus by the company4 ,although the most anxious care was exercised in every detail1 yet1 when #a1ahf miles had been laid1 the cable parted in #aa1jjj feet of water1 and although thrice it was grappled and brought toward the surface1 thrice it slipped off the grappling hooks and escaped to the ocean floor4 ,mr4 ,field was obliged to return to ,england and face as best he might the men whose capital lay at the bottom of the sea--perchance as worthless as so much ,atlantic ooze4 ,with heroic persistence he argued that all difficulties would yield to a renewed attack4 ,there must be redoubled precautions and vigilance never for a moment relaxed4 ,everything that deep-sea telegraphy has since accomplished was at that moment daylight clear to his prophetic view4 ,never has there been a more signal example of the power of enthusiasm to stir cold-blooded men of business2 never has there been a more striking illustration of how much science may depend for success upon the intelligence and the courage of capital4 ,electricians might have gone on perfecting exquisite apparatus for ocean telegraphy1 or indicated the weak points in the comparatively rude machinery which made and laid the cable1 yet their exertions would have been wasted if men of wealth had not responded to ,mr4 ,field's renewed appeal for help4 ,thrice these men had invested largely1 and thrice disaster had pursued their ventures2 nevertheless they had faith surviving all misfortunes for a fourth attempt4 ,in #ahff a new company was organized1 for two objects3 first1 to recover the cable lost the previous year and complete it to the ,american shore2 second1 to lay another beside it in a parallel course4 ,the ,great ,eastern was again put in commission1 and remodelled in accordance with the experience of her preceding voyage4 ,this time the exterior wires of the cable were of galvanized iron1 the better to resist corrosion4 ,the paying-out machinery was reconstructed and greatly improved4 ,on ,july #ac1 #ahff1 the huge steamer began running out her cable twenty-five miles north of the line struck out during the expedition of #ahfe2 she arrived without mishap in ,newfoundland on ,july #bg1 and electrical communication was re-established between ,america and ,europe4 ,the steamer now returned to the spot where she had lost the cable a few months before2 after eighteen days' search it was brought to the deck in good order4 ,union was effected with the cable stowed in the tanks below1 and the prow of the vessel was once more turned to ,newfoundland4 ,on ,september #hth this second cable was safely landed at ,trinity ,bay4 ,misfortunes now were at an end2 the courage of ,mr4 ,field knew victory at last2 the highest honors of two continents were showered upon him4 ',tis not the grapes of ,canaan that repay1 ,but the high faith that failed not by the way4 ,illustration3 ,fig4 #ei4--;,commercial cable1 #ahid ,what at first was as much a daring adventure as a business enterprise has now taken its place as a task no more out of the common than building a steamship1 or rearing a cantilever bridge4 ,given its price1 which will include too moderate a profit to betray any expectation of failure1 and a responsible firm will contract to lay a cable across the ,pacific itself4 ,in the ,atlantic lines the uniformly low temperature of the ocean floor 7about #d deg4 ,c471 and the great pressure of the superincumbent sea1 co-operate in effecting an enormous enhancement both in the insulation and in the carrying capacity of the wire4 ,as an example of recent work in ocean telegraphy let us glance at the cable laid in #ahid1 by the ,commercial ,cable ,company of ,new ,york4 ,it unites ,cape ,canso1 on the northeastern coast of ,nova ,scotia1 to ,waterville1 on the southwestern coast of ,ireland4 ,the central portion of this cable much resembles that of its predecessor in #ahff4 ,its exterior armour of steel wires is much more elaborate4 ,the first part of ,fig4 #ei shows the details of manufacture3 the central copper core is covered with gutta-percha1 then with jute1 upon which the steel wires are spirally wound1 followed by a strong outer covering4 ,for the greatest depths at sea1 type ,a is employed for a total length of #a1dbj miles2 the diameter of this part of the cable is seven-eighths of an inch4 ,as the water lessens in depth the sheathing increases in size until the diameter of the cable becomes one and one-sixteenth inches for #aeb miles1 as type ,b4 ,the cable now undergoes a third enlargement1 and then its fourth and last proportions are presented as it touches the shore1 for a distance of one and three-quarter miles1 where type ,c has a diameter of two and one-half inches4 ,the weights of material used in this cable are3 copper wire1 #die tons2 gutta-percha1 #cae tons2 jute yarn1 #ege tons2 steel wire1 #c1jjj tons2 compound and tar1 #a1jge tons2 total1 #e1dfj tons4 ,the telegraph-ship ,faraday1 specially designed for cable-laying1 accomplished the work without mishap4 ,electrical science owes much to the ,atlantic cables1 in particular to the first of them4 ,at the very beginning it banished the idea that electricity as it passes through metallic conductors has anything like its velocity through free space4 ,it was soon found1 as ,professor ,mendenhall says1 that it is no more correct to assign a definite velocity to electricity than to a river4 ,as the rate of flow of a river is determined by the character of its bed1 its gradient1 and other circumstances1 so the velocity of an electric current is found to depend on the conditions under which the flow takes place4#b ,mile for mile the original ,atlantic cable had twenty times the retarding effect of a good aerial line2 the best recent cables reduce this figure by nearly one-half4 ,in an extreme form1 this slowing down reminds us of the obstruction of light as it enters the atmosphere of the earth1 of the further impediment which the rays encounter if they pass from the air into the sea4 ,in the main the causes which hinder a pulse committed to a cable are two3 induction1 and the electrostatic capacity of the wire1 that is1 the capacity of the wire to take up a charge of its own1 just as if it were the metal of a ,leyden jar4 ,let us first consider induction4 ,as a current takes its way through the copper core it induces in its surroundings a second and opposing current4 ,for this the remedy is one too costly to be applied4 ,were a cable manufactured in a double line1 as in the best telephonic circuits1 induction1 with its retarding and quenching effects1 would be neutralized4 ,here the steel wire armour which encircles the cable plays an unwelcome part4 ,induction is always proportioned to the conductivity of the mass in which it appears2 as steel is an excellent conductor1 the armour of an ocean cable1 close as it is to the copper core1 has induced in it a current much stronger1 and therefore more retarding1 than if the steel wire were absent4 ,a word now as to the second difficulty in working beneath the sea--that due to the absorbing power of the line itself4 ,an ,atlantic cable1 like any other extended conductor1 is virtually a long1 cylindrical ,leyden jar1 the copper wire forming the inner coat1 and its surroundings the outer coat4 ,before a signal can be received at the distant terminus the wire must first be charged4 ,the effect is somewhat like transmitting a signal through water which fills a rubber tube2 first of all the tube is distended1 and its compression1 or secondary effect1 really transmits the impulse4 ,a remedy for this is a condenser formed of alternate sheets of tin-foil and mica1 ,c1 connected with the battery1 ,b1 so as to balance the electric charge of the cable wire 7,fig4 #fj74 ,in the first ,atlantic line an impulse demanded one-seventh of a second for its journey4 ,this was reduced when ,mr4 ,whitehouse made the capital discovery that the speed of a signal is increased threefold when the wire is alternately connected with the zinc and copper poles of the battery4 ,sir ,william ,thomson ascertained that these successive pulses are most effective when of proportioned lengths4 ,he accordingly devised an automatic transmitter which draws a duly perforated slip of paper under a metallic spring connected with the cable4 ,to-day #bej to #cjj letters are sent per minute instead of fifteen1 as at first4 ,illustration3 ,fig4 #fj4--;,condenser ,in many ways a deep-sea cable exaggerates in an instructive manner the phenomena of telegraphy over long aerial lines4 ,the two ends of a cable may be in regions of widely diverse electrical potential1 or pressure1 just as the readings of the barometer at these two places may differ much4 ,if a copper wire were allowed to offer itself as a gateless conductor it would equalize these variations of potential with serious injury to itself4 ,accordingly the rule is adopted of working the cable not directly1 as if it were a land line1 but indirectly through condensers4 ,as the throb sent through such apparatus is but momentary1 the cable is in no risk from the strong currents which would course through it if it were permitted to be an open channel4 ,illustration3 ,fig4 #fa4--,reflecting galvanometer ,l1 lamp2 ,n1 moving spot of light reflected from mirror ,a serious error in working the first cables was in supposing that they required strong currents as in land lines of considerable length4 ,the very reverse is the fact4 ,mr4 ,charles ,bright1 in ,submarine ,telegraphs1 says3 ,mr4 ,latimer ,clark had the conductor of the #ahfe and #ahff lines joined together at the ,newfoundland end1 thus forming an unbroken length of #c1gjj miles in circuit4 ,he then placed some sulphuric acid in a very small silver thimble1 with a fragment of zinc weighing a grain or two4 ,by this primitive agency he succeeded in conveying signals through twice the breadth of the ,atlantic ,ocean in little more than a second of time after making contact4 ,the deflections were not of a dubious character1 but full and strong1 from which it was manifest than an even smaller battery would suffice to produce somewhat similar effects4 ,illustration3 ,fig4 #fb4--,siphon recorder ,at first in operating the ,atlantic cable a mirror galvanometer was employed as a receiver4 ,the principle of this receiver has often been illustrated by a mischievous boy as1 with a slight and almost imperceptible motion of his hand1 he has used a bit of looking-glass to dart a ray of reflected sunlight across a wide street or a large room4 ,on the same plan1 the extremely minute motion of a galvanometer1 as it receives the successive pulsations of a message1 is magnified by a weightless lever of light so that the words are easily read by an operator 7,fig4 #fa74 ,this beautiful invention comes from the hands of ,sir ,william ,thomson now ,lord ,kelvin1 who1 more than any other electrician1 has made ocean telegraphy an established success4 ,illustration3 ,fig4 #fc4--,siphon record4 ,arrived yesterday ,in another receiver1 also of his design1 the siphon recorder1 he began by taking advantage of the fact1 observed long before by ,bose1 that a charge of electricity stimulates the flow of a liquid4 ,in its original form the ink-well into which the siphon dipped was insulated and charged to a high voltage by an influence-machine2 the ink1 powerfully repelled1 was spurted from the siphon point to a moving strip of paper beneath 7,fig4 #fb74 ,it was afterward found better to use a delicate mechanical shaker which throws out the ink in minute drops as the cable current gently sways the siphon back and forth 7,fig4 #fc74 ,minute as the current is which suffices for cable telegraphy1 it is essential that the metallic circuit be not only unbroken1 but unimpaired throughout4 ,no part of his duty has more severely taxed the resources of the electrician than to discover the breaks and leaks in his ocean cables4 ,one of his methods is to pour electricity as it were1 into a broken wire1 much as if it were a narrow tube1 and estimate the length of the wire 7and consequently the distance from shore to the defect or break7 by the quantity of current required to fill it4 ,,footnotes3 #a ,henry ,m4 ,field1 ,history of the ,atlantic ,telegraph4 ,new ,york3 ,scribner1 #ahff4 #b ,a ,century of ,electricity4 ,boston1 ,houghton1 ,mifflin ,co41 #ahhg4 ,,bell',s ,,telephonic ,,researches ,from ,bell's ,electric ,speaking ,telephones1 by ,george ,b4 ,prescott1 copyright by ,d ,appleton ,co41 ,new ,york1 #ahhd ,in a lecture delivered before the ,society of ,telegraph ,engineers1 in ,london1 ,october #ca1 #ahgg1 ,prof4 ,a4 ,g4 ,bell gave a history of his researches in telephony1 together with the experiments that he was led to undertake in his endeavours to produce a practical system of multiple telegraphy1 and to realize also the transmission of articulate speech4 ,after the usual introduction1 ,professor ,bell said in part3 ,it is to-night my pleasure1 as well as duty1 to give you some account of the telephonic researches in which ,i have been so long engaged4 ,many years ago my attention was directed to the mechanism of speech by my father1 ,alexander ,melville ,bell1 of ,edinburgh1 who has made a life-long study of the subject4 ,many of those present may recollect the invention by my father of a means of representing1 in a wonderfully accurate manner1 the positions of the vocal organs in forming sounds4 ,together we carried on quite a number of experiments1 seeking to discover the correct mechanism of ,english and foreign elements of speech1 and ,i remember especially an investigation in which we were engaged concerning the musical relations of vowel sounds4 ,when vocal sounds are whispered1 each vowel seems to possess a particular pitch of its own1 and by whispering certain vowels in succession a musical scale can be distinctly perceived4 ,our aim was to determine the natural pitch of each vowel2 but unexpected difficulties made their appearance1 for many of the vowels seemed to possess a double pitch--one due1 probably1 to the resonance of the air in the mouth1 and the other to the resonance of the air contained in the cavity behind the tongue1 comprehending the pharynx and larynx4 ,i hit upon an expedient for determining the pitch1 which1 at that time1 ,i thought to be original with myself4 ,it consisted in vibrating a tuning fork in front of the mouth while the positions of the vocal organs for the various vowels were silently taken4 ,it was found that each vowel position caused the reinforcement of some particular fork or forks4 ,i wrote an account of these researches to ,mr4 ,alex4 ,j4 ,ellis1 of ,london4 ,in reply1 he informed me that the experiments related had already been performed by ,helmholtz1 and in a much more perfect manner than ,i had done4 ,indeed1 he said that ,helmholtz had not only analyzed the vowel sounds into their constituent musical elements1 but had actually performed the synthesis of them4 ,he had succeeded in producing1 artificially1 certain of the vowel sounds by causing tuning forks of different pitch to vibrate simultaneously by means of an electric current4 ,mr4 ,ellis was kind enough to grant me an interview for the purpose of explaining the apparatus employed by ,helmholtz in producing these extraordinary effects1 and ,i spent the greater part of a delightful day with him in investigating the subject4 ,at that time1 however1 ,i was too slightly acquainted with the laws of electricity fully to understand the explanations given2 but the interview had the effect of arousing my interest in the subjects of sound and electricity1 and ,i did not rest until ,i had obtained possession of a copy of ,helmholtz's great work ,the ,theory of ,tone1 and had attempted1 in a crude and imperfect manner1 it is true1 to reproduce his results4 ,while reflecting upon the possibilities of the production of sound by electrical means1 it struck me that the principle of vibrating a tuning fork by the intermittent attraction of an electro-magnet might be applied to the electrical production of music4 ,i imagined to myself a series of tuning forks of different pitches1 arranged to vibrate automatically in the manner shown by ,helmholtz--each fork interrupting1 at every vibration1 a voltaic current--and the thought occurred1 ,why should not the depression of a key like that of a piano direct the interrupted current from any one of these forks1 through a telegraph wire1 to a series of electro-magnets operating the strings of a piano or other musical instrument1 in which case a person might play the tuning fork piano in one place and the music be audible from the electro-magnetic piano in a distant city4 ,the more ,i reflected upon this arrangement the more feasible did it seem to me2 indeed1 ,i saw no reason why the depression of a number of keys at the tuning fork end of the circuit should not be followed by the audible production of a full chord from the piano in the distant city1 each tuning fork affecting at the receiving end that string of the piano with which it was in unison4 ,at this time the interest which ,i felt in electricity led me to study the various systems of telegraphy in use in this country and in ,america4 ,i was much struck with the simplicity of the ,morse alphabet1 and with the fact that it could be read by sound4 ,instead of having the dots and dashes recorded on paper1 the operators were in the habit of observing the duration of the click of the instruments1 and in this way were enabled to distinguish by ear the various signals4 ,it struck me that in a similar manner the duration of a musical note might be made to represent the dot or dash of the telegraph code1 so that a person might operate one of the keys of the tuning fork piano referred to above1 and the duration of the sound proceeding from the corresponding string of the distant piano be observed by an operator stationed there4 ,it seemed to me that in this way a number of distinct telegraph messages might be sent simultaneously from the tuning fork piano to the other end of the circuit by operators1 each manipulating a different key of the instrument4 ,these messages would be read by operators stationed at the distant piano1 each receiving operator listening for signals for a certain definite pitch1 and ignoring all others4 ,in this way could be accomplished the simultaneous transmission of a number of telegraphic messages along a single wire1 the number being limited only by the delicacy of the listener's ear4 ,the idea of increasing the carrying power of a telegraph wire in this way took complete possession of my mind1 and it was this practical end that ,i had in view when ,i commenced my researches in electric telephony4 ,illustration3 ,fig4 #a ,in the progress of science it is universally found that complexity leads to simplicity1 and in narrating the history of scientific research it is often advisable to begin at the end4 ,in glancing back over my own researches1 ,i find it necessary to designate1 by distinct names1 a variety of electrical currents by means of which sounds can be produced1 and ,i shall direct your attention to several distinct species of what may be termed telephonic currents of electricity4 ,in order that the peculiarities of these currents may be clearly understood1 ,i shall project upon the screen a graphical illustration of the different varieties4 ,the graphical method of representing electrical currents shown in ,fig4 #a is the best means ,i have been able to devise of studying1 in an accurate manner1 the effects produced by various forms of telephonic apparatus1 and it has led me to the conception of that peculiar species of telephonic current1 here designated as undulatory1 which has rendered feasible the artificial production of articulate speech by electrical means4 ,a horizontal line 7g g'7 is taken as the zero of current1 and impulses of positive electricity are represented above the zero line1 and negative impulses below it1 or vice versa4 ,the vertical thickness of any electrical impulse 7b or d71 measured from the zero line1 indicates the intensity of the electrical current at the point observed2 and the horizontal extension of the electric line 7b or d7 indicates the duration of the impulse4 ,nine varieties of telephonic currents may be distinguished1 but it will only be necessary to show you six of these4 ,the three primary varieties designated as intermittent1 pulsatory and undulatory1 are represented in lines #a1 #b and #c4 ,sub-varieties of these can be distinguished as direct or reversed currents1 according as the electrical impulses are all of one kind or are alternately positive and negative4 ,direct currents may still further be distinguished as positive or negative1 according as the impulses are of one kind or of the other4 ,an intermittent current is characterized by the alternate presence and absence of electricity upon the circuit4 ,a pulsatory current results from sudden or instantaneous changes in the intensity of a continuous current2 and ,an undulatory current is a current of electricity1 the intensity of which varies in a manner proportional to the velocity of the motion of a particle of air during the production of a sound3 thus the curve representing graphically the undulatory current for a simple musical note is the curve expressive of a simple pendulous vibration--that is1 a sinusoidal curve4 ,and here ,i may remark1 that1 although the conception of the undulatory current of electricity is entirely original with myself1 methods of producing sound by means of intermittent and pulsatory currents have long been known4 ,for instance1 it was long since discovered that an electro-magnet gives forth a decided sound when it is suddenly magnetized or demagnetized4 ,when the circuit upon which it is placed is rapidly made and broken1 a succession of explosive noises proceeds from the magnet4 ,these sounds produce upon the ear the effect of a musical note when the current is interrupted a sufficient number of times per second4444 ,illustration3 ,fig4 #b ,for several years my attention was almost exclusively directed to the production of an instrument for making and breaking a voltaic circuit with extreme rapidity1 to take the place of the transmitting tuning fork used in ,helmholtz's researches4 ,without going into details1 ,i shall merely say that the great defects of this plan of multiple telegraphy were found to consist1 first1 in the fact that the receiving operators were required to possess a good musical ear in order to discriminate the signals2 and secondly1 that the signals could only pass in one direction along the line 7so that two wires would be necessary in order to complete communication in both directions74 ,the first objection was got over by employing the device which ,i term a vibratory circuit breaker1 whereby musical signals can be automatically recorded4444 ,i have formerly stated that ,helmholtz was enabled to produce vowel sounds artificially by combining musical tones of different pitches and intensities4 ,his apparatus is shown in ,fig4 #b4 ,tuning forks of different pitch are placed between the poles of electro-magnets 7a#a1 a#b1 c471 and are kept in continuous vibration by the action of an intermittent current from the fork b4 ,resonators1 #a1 #b1 #c1 etc41 are arranged so as to reinforce the sounds in a greater or less degree1 according as the exterior orifices are enlarged or contracted4 ,illustration3 ,fig4 #c ,thus it will be seen that upon ,helmholtz's plan the tuning forks themselves produce tones of uniform intensity1 the loudness being varied by an external reinforcement2 but it struck me that the same results would be obtained1 and in a much more perfect manner1 by causing the tuning forks themselves to vibrate with different degrees of amplitude4 ,i therefore devised the apparatus shown in ,fig4 #c1 which was my first form of articulating telephone4 ,in this figure a harp of steel rods is employed1 attached to the poles of a permanent magnet1 ,n4 ,s4 ,when any one of the rods is thrown into vibration an undulatory current is produced in the coils of the electro-magnet ,e1 and the electro-magnet ,e' attracts the rods of the harp ,h' with a varying force1 throwing into vibration that rod which is in unison with that vibrating at the other end of the circuit4 ,not only so1 but the amplitude of vibration in the one will determine the amplitude of vibration in the other1 for the intensity of the induced current is determined by the amplitude of the inducing vibration1 and the amplitude of the vibration at the receiving end depends upon the intensity of the attractive impulses4 ,when we sing into a piano1 certain of the strings of the instrument are set in vibration sympathetically by the action of the voice with different degrees of amplitude1 and a sound1 which is an approximation to the vowel uttered1 is produced from the piano4 ,theory shows that1 had the piano a very much larger number of strings to the octave1 the vowel sounds would be perfectly reproduced4 ,my idea of the action of the apparatus1 shown in ,fig4 #c1 was this3 ,utter a sound in the neighbourhood of the harp ,h1 and certain of the rods would be thrown into vibration with different amplitudes4 ,at the other end of the circuit the corresponding rods of the harp ,h would vibrate with their proper relations of force1 and the timbre characteristic quality of the sound would be reproduced4 ,the expense of constructing such an apparatus as that shown in figure #c deterred me from making the attempt1 and ,i sought to simplify the apparatus before venturing to have it made4 ,illustration3 ,fig4 #d ,illustration3 ,fig4 #e ,illustration3 ,fig4 #f ,i have before alluded to the invention by my father of a system of physiological symbols for representing the action of the vocal organs1 and ,i had been invited by the ,boston ,board of ,education to conduct a series of experiments with the system in the ,boston school for the deaf and dumb4 ,it is well known that deaf mutes are dumb merely because they are deaf1 and that there is no defect in their vocal organs to incapacitate them from utterance4 ,hence it was thought that my father's system of pictorial symbols1 popularly known as visible speech1 might prove a means whereby we could teach the deaf and dumb to use their vocal organs and to speak4 ,the great success of these experiments urged upon me the advisability of devising method of exhibiting the vibrations of sound optically1 for use in teaching the deaf and dumb4 ,for some time ,i carried on experiments with the manometric capsule of ,koeenig and with the phonautograph of ,leon ,scott4 ,the scientific apparatus in the ,institute of ,technology in ,boston was freely placed at my disposal for these experiments1 and it happened that at that time a student of the ,institute of ,technology1 ,mr4 ,maurey1 had invented an improvement upon the phonautograph4 ,he had succeeded in vibrating by the voice a stylus of wood about a foot in length1 which was attached to the membrane of the phonautograph1 and in this way he had been enabled to obtain enlarged tracings upon a plane surface of smoked glass4 ,with this apparatus ,i succeeded in producing very beautiful tracings of the vibrations of the air for vowel sounds4 ,some of these tracings are shown in ,fig4 #d4 ,i was much struck with this improved form of apparatus1 and it occurred to me that there was a remarkable likeness between the manner in which this piece of wood was vibrated by the membrane of the phonautograph and the manner in which the ossiculo small bones of the human ear were moved by the tympanic membrane4 ,i determined therefore1 to construct a phonautograph modelled still more closely upon the mechanism of the human ear1 and for this purpose ,i sought the assistance of a distinguished aurist in ,boston1 ,dr4 ,clarence ,j4 ,blake4 ,he suggested the use of the human ear itself as a phonautograph1 instead of making an artificial imitation of it4 ,the idea was novel and struck me accordingly1 and ,i requested my friend to prepare a specimen for me1 which he did4 ,the apparatus1 as finally constructed1 is shown in ,fig4 #e4 ,the stapes inmost of the three auditory ossicles was removed and a pointed piece of hay about an inch in length was attached to the end of the incus the middle of the three auditory ossicles4 ,upon moistening the membrana tympani membrane of the ear drum and the ossiculae with a mixture of glycerine and water the necessary mobility of the parts was obtained1 and upon singing into the external artificial ear the piece of hay was thrown into vibration1 and tracings were obtained upon a plane surface of smoked glass passed rapidly underneath4 ,while engaged in these experiments ,i was struck with the remarkable disproportion in weight between the membrane and the bones that were vibrated by it4 ,it occurred to me that if a membrane as thin as tissue paper could control the vibration of bones that were1 compared to it1 of immense size and weight1 why should not a larger and thicker membrane be able to vibrate a piece of iron in front of an electro-magnet1 in which case the complication of steel rods shown in my first form of telephone1 ,fig4 #c1 could be done away with1 and a simple piece of iron attached to a membrane be placed at either end of the telegraphic circuit4 ,figure #f shows the form of apparatus that ,i was then employing for producing undulatory currents of electricity for the purpose of multiple telegraphy4 ,a steel reed1 ,a1 was clamped firmly by one extremity to the uncovered leg h of an electro-magnet ,e1 and the free end of the reed projected above the covered leg4 ,when the reed ,a was vibrated in any mechanical way the battery current was thrown into waves1 and electrical undulations traversed the circuit ,b ,e ,w ,e'1 throwing into vibration the corresponding reed ,a' at the other end of the circuit4 ,i immediately proceeded to put my new idea to the test of practical experiment1 and for this purpose ,i attached the reed ,a 7,fig4 #g7 loosely by one extremity to the uncovered pole h of the magnet1 and fastened the other extremity to the centre of a stretched membrane of goldbeaters' skin n4 ,i presumed that upon speaking in the neighbourhood of the membrane n it would be thrown into vibration and cause the steel reed ,a to move in a similar manner1 occasioning undulations in the electrical current that would correspond to the changes in the density of the air during the production of the sound2 and ,i further thought that the change of the density of the current at the receiving end would cause the magnet there to attract the reed ,a' in such a manner that it should copy the motion of the reed ,a1 in which case its movements would occasion a sound from the membrane n' similar in timbre to that which had occasioned the original vibration4 ,illustration3 ,fig4 #g ,illustration3 ,fig4 #h ,the results1 however1 were unsatisfactory and discouraging4 ,my friend1 ,mr4 ,thomas ,a4 ,watson1 who assisted me in this first experiment1 declared that he heard a faint sound proceed from the telephone at his end of the circuit1 but ,i was unable to verify his assertion4 ,after many experiments1 attended by the same only partially successful results1 ,i determined to reduce the size and weight of the spring as much as possible4 ,for this purpose ,i glued a piece of clock spring about the size and shape of my thumb nail1 firmly to the centre of the diaphragm1 and had a similar instrument at the other end 7,fig4 #h72 we were then enabled to obtain distinctly audible effects4 ,i remember an experiment made with this telephone1 which at the time gave me great satisfaction and delight4 ,one of the telephones was placed in my lecture room in the ,boston ,university1 and the other in the basement of the adjoining building4 ,one of my students repaired to the distant telephone to observe the effects of articulate speech1 while ,i uttered the sentence1 ,do you understand what ,i say8 into the telephone placed in the lecture hall4 ,to my delight an answer was returned through the instrument itself1 articulate sounds proceeded from the steel spring attached to the membrane1 and ,i heard the sentence1 ,yes1 ,i understand you perfectly4 ,it is a mistake1 however1 to suppose that the articulation was by any means perfect1 and expectancy no doubt had a great deal to do with my recognition of the sentence2 still1 the articulation was there1 and ,i recognized the fact that the indistinctness was entirely due to the imperfection of the instrument4 ,i will not trouble you by detailing the various stages through which the apparatus passed1 but shall merely say that after a time ,i produced the form of instrument shown in ,fig4 #i1 which served very well as a receiving telephone4 ,in this condition my invention was1 in #ahgf1 exhibited at the ,centennial ,exhibition in ,philadelphia4 ,the telephone shown in ,fig4 #h was used as a transmitting instrument1 and that in ,fig4 #i as a receiver1 so that vocal communication was only established in one direction4444 ,illustration3 ,fig4 #i ,the articulation produced from the instrument shown in ,fig4 #i was remarkably distinct1 but its great defect consisted in the fact that it could not be used as a transmitting instrument1 and thus two telephones were required at each station1 one for transmitting and one for receiving spoken messages4 ,illustration3 ,fig4 #aj ,it was determined to vary the construction of the telephone shown in ,fig4 #h1 and ,i sought1 by changing the size and tension of the membrane1 the diameter and thickness of the steel spring1 the size and power of the magnet1 and the coils of insulated wire around their poles1 to discover empirically the exact effect of each element of the combination1 and thus to deduce a more perfect form of apparatus4 ,it was found that a marked increase in the loudness of the sounds resulted from shortening the length of the coils of wire1 and by enlarging the iron diaphragm which was glued to the membrane4 ,in the latter case1 also1 the distinctness of the articulation was improved4 ,finally1 the membrane of goldbeaters' skin was discarded entirely1 and a simple iron plate was used instead1 and at once intelligible articulation was obtained4 ,the new form of instrument is that shown in ,fig4 #aj1 and1 as had been long anticipated1 it was proved that the only use of the battery was to magnetize the iron core1 for the effects were equally audible when the battery was omitted and a rod of magnetized steel substituted for the iron core of the magnet4 ,illustration3 ,fig4 #aa ,it was my original intention1 as shown in ,fig4 #c1 and it was always claimed by me1 that the final form of telephone would be operated by permanent magnets in place of batteries1 and numerous experiments had been carried on by ,mr4 ,watson and myself privately for the purpose of producing this effect4 ,at the time the instruments were first exhibited in public the results obtained with permanent magnets were not nearly so striking as when a voltaic battery was employed1 wherefore we thought it best to exhibit only the latter form of instrument4 ,the interest excited by the first published accounts of the operation of the telephone led many persons to investigate the subject1 and ,i doubt not that numbers of experimenters have independently discovered that permanent magnets might be employed instead of voltaic batteries4 ,indeed1 one gentleman1 ,professor ,dolbear1 of ,tufts ,college1 not only claims to have discovered the magneto-electric telephone1 but1 ,i understand1 charges me with having obtained the idea from him through the medium of a mutual friend4 ,a still more powerful form of apparatus was constructed by using a powerful compound horseshoe magnet in place of the straight rod which had been previously used 7see ,fig4 #aa74 ,indeed1 the sounds produced by means of this instrument were of sufficient loudness to be faintly audible to a large audience1 and in this condition the instrument was exhibited in the ,essex ,institute1 in ,salem1 ,massachusetts1 on the #abth of ,february1 #ahgg1 on which occasion a short speech shouted into a similar telephone in ,boston sixteen miles away1 was heard by the audience in ,salem4 ,the tones of the speaker's voice were distinctly audible to an audience of six hundred people1 but the articulation was only distinct at a distance of about six feet4 ,on the same occasion1 also1 a report of the lecture was transmitted by word of mouth from ,salem to ,boston1 and published in the papers the next morning4 ,from the form of telephone shown in ,fig4 #aj to the present form of the instrument 7,fig4 #ab7 is but a step4 ,it is1 in fact1 the arrangement of ,fig4 #aj in a portable form1 the magnet ,f4 ,h4 being placed inside the handle and a more convenient form of mouthpiece provided4444 ,it was always my belief that a certain ratio would be found between the several parts of a telephone1 and that the size of the instrument was immaterial2 but ,professor ,peirce was the first to demonstrate the extreme smallness of the magnets which might be employed4 ,and here1 in order to show the parallel lines in which we were working1 ,i may mention the fact that two or three days after ,i had constructed a telephone of the portable form 7,fig4 #ab71 containing the magnet inside the handle1 ,dr4 ,channing was kind enough to send me a pair of telephones of a similar pattern1 which had been invented by experimenters at ,providence4 ,the convenient form of the mouthpiece shown in ,fig4 #ab1 now adopted by me1 was invented solely by my friend1 ,professor ,peirce4 ,i must also express my obligations to my friend and associate1 ,mr4 ,thomas ,a4 ,watson1 of ,salem1 ,massachusetts1 who has for two years past given me his personal assistance in carrying on my researches4 ,in pursuing my investigations ,i have ever had one end in view--the practical improvement of electric telegraphy--but ,i have come across many facts which1 while having no direct bearing upon the subject of telegraphy1 may yet possess an interest for you4 ,for instance1 ,i have found that a musical tone proceeds from a piece of plumbago or retort carbon when an intermittent current of electricity is passed through it1 and ,i have observed the most curious audible effects produced by the passage of reversed intermittent currents through the human body4 ,a breaker was placed in circuit with the primary wires of an induction coil1 and the fine wires were connected with two strips of brass4 ,one of these strips was held closely against the ear1 and a loud sound proceeded from it whenever the other slip was touched with the other hand4 ,the strips of brass were next held one in each hand4 ,the induced currents occasioned a muscular tremor in the fingers4 ,upon placing my forefinger to my ear a loud crackling noise was audible1 seemingly proceeding from the finger itself4 ,a friend who was present placed my finger to his ear1 but heard nothing4 ,i requested him to hold the strips himself4 ,he was then distinctly conscious of a noise 7which ,i was unable to perceive7 proceeding from his finger4 ,in this case a portion of the induced current passed through the head of the observer when he placed his ear against his own finger1 and it is possible that the sound was occasioned by a vibration of the surfaces of the ear and finger in contact4 ,when two persons receive a shock from a ,ruhmkorff's coil by clasping hands1 each taking hold of one wire of the coil with the free hand1 a sound proceeds from the clasped hands4 ,the effect is not produced when the hands are moist4 ,when either of the two touches the body of the other a loud sound comes from the parts in contact4 ,when the arm of one is placed against the arm of the other1 the noise produced can be heard at a distance of several feet4 ,in all these cases a slight shock is experienced so long as the contact is preserved4 ,the introduction of a piece of paper between the parts in contact does not materially interfere with the production of the sounds1 but the unpleasant effects of the shock are avoided4 ,illustration3 ,fig4 #ab ,when an intermittent current from a ,ruhmkorff's coil is passed through the arms a musical note can be perceived when the ear is closely applied to the arm of the person experimented upon4 ,the sound seems to proceed from the muscles of the fore-arm and from the biceps muscle4 ,mr4 ,elisha ,gray has also produced audible effects by the passage of electricity through the human body4 ,an extremely loud musical note is occasioned by the spark of a ,ruhmkorff's coil when the primary circuit is made and broken with sufficient rapidity4 ,when two breakers of different pitch are caused simultaneously to open and close the primary circuit a double tone proceeds from the spark4 ,a curious discovery1 which may be of interest to you1 has been made by ,professor ,blake4 ,he constructed a telephone in which a rod of soft iron1 about six feet in length1 was used instead of a permanent magnet4 ,a friend sang a continuous musical tone into the mouthpiece of a telephone1 like that shown in ,fig4 #ab1 which was connected with the soft iron instrument alluded to above4 ,it was found that the loudness of the sound produced in this telephone varied with the direction in which the iron rod was held1 and that the maximum effect was produced when the rod was in the position of the dipping needle4 ,this curious discovery of ,professor ,blake has been verified by myself4 ,when a telephone is placed in circuit with a telegraph line the telephone is found seemingly to emit sounds on its own account4 ,the most extraordinary noises are often produced1 the causes of which are at present very obscure4 ,one class of sounds is produced by the inductive influence of neighbouring wires and by leakage from them1 the signals of the ,morse alphabet passing over neighbouring wires being audible in the telephone1 and another class can be traced to earth currents upon the wire1 a curious modification of this sound revealing the presence of defective joints in the wire4 ,professor ,blake informs me that he has been able to use the railroad track for conversational purposes in place of a telegraph wire1 and he further states that when only one telephone was connected with the track the sounds of ,morse operating were distinctly audible in the telephone1 although the nearest telegraph wires were at least fifty feet distant4 ,professor ,peirce has observed the most singular sounds produced from a telephone in connection with a telegraph wire during the aurora borealis1 and ,i have just heard of a curious phenomenon lately observed by ,dr4 ,channing4 ,in the city of ,providence1 ,rhode ,island1 there is an over-house wire about one mile in extent with a telephone at either end4 ,on one occasion the sound of music and singing was faintly audible in one of the telephones4 ,it seemed as if some one were practising vocal music with a pianoforte accompaniment4 ,the natural supposition was that experiments were being made with the telephone at the other end of the circuit1 but upon inquiry this proved not to have been the case4 ,attention having thus been directed to the phenomenon1 a watch was kept upon the instruments1 and upon a subsequent occasion the same fact was observed at both ends of the line by ,dr4 ,channing and his friends4 ,it was proved that the sounds continued for about two hours1 and usually commenced about the same time4 ,a searching examination of the line disclosed nothing abnormal in its condition1 and ,i am unable to give you any explanation of this curious phenomenon4 ,dr4 ,channing has1 however1 addressed a letter upon the subject to the editor of one of the ,providence papers1 giving the names of such songs as were recognized1 and full details of the observations1 in the hope that publicity may lead to the discovery of the performer1 and thus afford a solution of the mystery4 ,my friend1 ,mr4 ,frederick ,a4 ,gower1 communicated to me a curious observation made by him regarding the slight earth connection required to establish a circuit for the telephone1 and together we carried on a series of experiments with rather startling results4 ,we took a couple of telephones and an insulated wire about #ajj yards in length into a garden1 and were enabled to carry on conversation with the greatest ease when we held in our hands what should have been the earth wire1 so that the connection with the ground was formed at either end through our bodies1 our feet being clothed with cotton socks and leather boots4 ,the day was fine1 and the grass upon which we stood was seemingly perfectly dry4 ,upon standing upon a gravel walk the vocal sounds1 though much diminished1 were still perfectly intelligible1 and the same result occurred when standing upon a brick wall one foot in height1 but no sound was audible when one of us stood upon a block of freestone4 ,one experiment which we made is so very interesting that ,i must speak of it in detail4 ,mr4 ,gower made earth connection at his end of the line by standing upon a grass plot1 whilst at the other end of the line ,i stood upon a wooden board4 ,i requested ,mr4 ,gower to sing a continuous musical note1 and to my surprise the sound was very distinctly audible from the telephone in my hand4 ,upon examining my feet ,i discovered that a single blade of grass was bent over the edge of the board1 and that my foot touched it4 ,the removal of this blade of grass was followed by the cessation of the sound from the telephone1 and ,i found that the moment ,i touched with the toe of my boot a blade of grass or the petal of a daisy the sound was again audible4 ,the question will naturally arise1 ,through what length of wire can the telephone be used8 ,in reply to this ,i may say that the maximum amount of resistance through which the undulatory current will pass1 and yet retain sufficient force to produce an audible sound at the distant end1 has yet to be determined2 no difficulty has1 however1 been experienced in laboratory experiments in conversing through a resistance of #fj1jjj ohms1 which has been the maximum at my disposal4 ,on one occasion1 not having a rheostat for producing resistance at hand1 ,i passed the current through the bodies of sixteen persons1 who stood hand in hand4 ,the longest length of real telegraph line through which ,i have attempted to converse has been about #bej miles4 ,on this occasion no difficulty was experienced so long as parallel lines were not in operation4 ,sunday was chosen as the day on which it was probable other circuits would be at rest4 ,conversation was carried on between myself1 in ,new ,york1 and ,mr4 ,thomas ,a4 ,watson1 in ,boston1 until the opening of business upon the other wires4 ,when this happened the vocal sounds were very much diminished1 but still audible4 ,it seemed1 indeed1 like talking through a storm4 ,conversation1 though possible1 could be carried on with difficulty1 owing to the distracting nature of the interfering currents4 ,i am informed by my friend ,mr4 ,preece that conversation has been successfully carried on through a submarine cable1 sixty miles in length1 extending from ,dartmouth to the ,island of ,guernsey1 by means of hand telephones4 ,,photographing ,,the ,,unseen3 ,,the ,,roentgen ,,ray ,h4 ,j4 ,w4 ,,dam ,by permission from ,mc,clure's ,magazine1 ,april1 #ahif1 copyright by ,s4 ,s4 ,mc,clure1 ,limited4 ,in all the history of scientific discovery there has never been1 perhaps1 so general1 rapid1 and dramatic an effect wrought on the scientific centres of ,europe as has followed1 in the past four weeks1 upon an announcement made to the ,wuerzburg ,physico-,medical ,society1 at their ,december #ahie meeting1 by ,professor ,william ,konrad ,roentgen1 professor of physics at the ,royal ,university of ,wuerzburg4 ,the first news which reached ,london was by telegraph from ,vienna to the effect that a ,professor ,roentgen1 until then the possessor of only a local fame in the town mentioned1 had discovered a new kind of light1 which penetrated and photographed through everything4 ,this news was received with a mild interest1 some amusement1 and much incredulity2 and a week passed4 ,then1 by mail and telegraph1 came daily clear indications of the stir which the discovery was making in all the great line of universities between ,vienna and ,berlin4 ,then ,roentgen's own report arrived1 so cool1 so business-like1 and so truly scientific in character1 that it left no doubt either of the truth or of the great importance of the preceding reports4 ,to-day1 four weeks after the announcement1 ,roentgen's name is apparently in every scientific publication issued this week in ,europe2 and accounts of his experiments1 of the experiments of others following his method1 and of theories as to the strange new force which he has been the first to observe1 fill pages of every scientific journal that comes to hand4 ,and before the necessary time elapses for this article to attain publication in ,america1 it is in all ways probable that the laboratories and lecture-rooms of the ,united ,states will also be giving full evidence of this contagious arousal of interest over a discovery so strange that its importance cannot yet be measured1 its utility be even prophesied1 or its ultimate effect upon long established scientific beliefs be even vaguely foretold4 ,the ,roentgen rays are certain invisible rays resembling1 in many respects1 rays of light1 which are set free when a high-pressure electric current is discharged through a vacuum tube4 ,a vacuum tube is a glass tube from which all the air1 down to one-millionth of an atmosphere1 has been exhausted after the insertion of a platinum wire in either end of the tube for connection with the two poles of a battery or induction coil4 ,when the discharge is sent through the tube1 there proceeds from the anode--that is1 the wire which is connected with the positive pole of the battery--certain bands of light1 varying in colour with the colour of the glass4 ,but these are insignificant in comparison with the brilliant glow which shoots from the cathode1 or negative wire4 ,this glow excites brilliant phosphorescence in glass and many substances1 and these cathode rays1 as they are called1 were observed and studied by ,hertz2 and more deeply by his assistant1 ,professor ,lenard1 ,lenard having1 in #ahid1 reported that the cathode rays would penetrate thin films of aluminum1 wood1 and other substances1 and produce photographic results beyond4 ,it was left1 however1 for ,professor ,roentgen to discover that during the discharge quite other rays are set free1 which differ greatly from those described by ,lenard as cathode rays4 ,the most marked difference between the two is the fact that ,roentgen rays are not deflected by a magnet1 indicating a very essential difference1 while their range and penetrative power are incomparably greater4 ,in fact1 all those qualities which have lent a sensational character to the discovery of ,roentgen's rays were mainly absent from those of ,lenard1 to the end that1 although ,roentgen has not been working in an entirely new field1 he has by common accord been freely granted all the honors of a great discovery4 ,exactly what kind of a force ,professor ,roentgen has discovered he does not know4 ,as will be seen below1 he declines to call it a new kind of light1 or a new form of electricity4 ,he has given it the name of the ,x rays4 ,others speak of it as the ,roentgen rays4 ,thus far its results only1 and not its essence1 are known4 ,in the terminology of science it is generally called a new mode of motion1 or1 in other words1 a new force4 ,as to whether it is or not actually a force new to science1 or one of the known forces masquerading under strange conditions1 weighty authorities are already arguing4 ,more than one eminent scientist has already affected to see in it a key to the great mystery of the law of gravity4 ,all who have expressed themselves in print have admitted1 with more or less frankness1 that1 in view of ,roentgen's discovery1 science must forthwith revise1 possibly to a revolutionary degree1 the long accepted theories concerning the phenomena of light and sound4 ,that the ,x rays1 in their mode of action1 combine a strange resemblance to both sound and light vibrations1 and are destined to materially affect1 if they do not greatly alter1 our views of both phenomena1 is already certain2 and beyond this is the opening into a new and unknown field of physical knowledge1 concerning which speculation is already eager1 and experimental investigation already in hand1 in ,london1 ,paris1 ,berlin1 and1 perhaps1 to a greater or less extent1 in every well-equipped physical laboratory in ,europe4 ,this is the present scientific aspect of the discovery4 ,but1 unlike most epoch-making results from laboratories1 this discovery is one which1 to a very unusual degree1 is within the grasp of the popular and non-technical imagination4 ,among the other kinds of matter which these rays penetrate with ease is human flesh4 ,that a new photography has suddenly arisen which can photograph the bones1 and1 before long1 the organs of the human body2 that a light has been found which can penetrate1 so as to make a photographic record1 through everything from a purse or a pocket to the walls of a room or a house1 is news which cannot fail to startle everybody4 ,that the eye of the physician or surgeon1 long baffled by the skin1 and vainly seeking to penetrate the unfortunate darkness of the human body1 is now to be supplemented by a camera1 making all the parts of the human body as visible1 in a way1 as the exterior1 appears certainly to be a greater blessing to humanity than even the ,listerian antiseptic system of surgery2 and its benefits must inevitably be greater than those conferred by ,lister1 great as the latter have been4 ,already1 in the few weeks since ,roentgen's announcement1 the results of surgical operations under the new system are growing voluminous4 ,in ,berlin1 not only new bone fractures are being immediately photographed1 but joined fractures1 as well1 in order to examine the results of recent surgical work4 ,in ,vienna1 imbedded bullets are being photographed1 instead of being probed for1 and extracted with comparative ease4 ,in ,london1 a wounded sailor1 completely paralyzed1 whose injury was a mystery1 has been saved by the photographing of an object imbedded in the spine1 which1 upon extraction1 proved to be a small knife-blade4 ,operations for malformations1 hitherto obscure1 but now clearly revealed by the new photography1 are already becoming common1 and are being reported from all directions4 ,professor ,czermark of ,graz has photographed the living skull1 denuded of flesh and hair1 and has begun the adaptation of the new photography to brain study4 ,the relation of the new rays to thought rays is being eagerly discussed in what may be called the non-exact circles and journals2 and all that numerous group of inquirers into the occult1 the believers in clairvoyance1 spiritualism1 telepathy1 and kindred orders of alleged phenomena1 are confident of finding in the new force long-sought facts in proof of their claims4 ,professor ,neusser in ,vienna has photographed gallstones in the liver of one patient 7the stone showing snow-white in the negative71 and a stone in the bladder of another patient4 ,his results so far induce him to announce that all the organs of the human body can1 and will1 shortly1 be photographed4 ,lannelongue of ,paris has exhibited to the ,academy of ,science photographs of bones showing inherited tuberculosis which had not otherwise revealed itself4 ,berlin has already formed a society of forty for the immediate prosecution of researches into both the character of the new force and its physiological possibilities4 ,in the next few weeks these strange announcements will be trebled or quadrupled1 giving the best evidence from all quarters of the great future that awaits the ,roentgen rays1 and the startling impetus to the universal search for knowledge that has come at the close of the nineteenth century from the modest little laboratory in the ,pleicher ,ring at ,wuerzburg4 ,the ,physical ,institute1 ,professor ,roentgen's particular domain1 is a modest building of two stories and basement1 the upper story constituting his private residence1 and the remainder of the building being given over to lecture rooms1 laboratories1 and their attendant offices4 ,at the door ,i was met by an old serving-man of the idolatrous order1 whose pain was apparent when ,i asked for ,professor ,roentgen1 and he gently corrected me with ,herr ,doctor ,roentgen4 ,as it was evident1 however1 that we referred to the same person1 he conducted me along a wide1 bare hall1 running the length of the building1 with blackboards and charts on the walls4 ,at the end he showed me into a small room on the right4 ,this contained a large table desk1 and a small table by the window1 covered by photographs1 while the walls held rows of shelves laden with laboratory and other records4 ,an open door led into a somewhat larger room1 perhaps twenty feet by fifteen1 and ,i found myself gazing into a laboratory which was the scene of the discovery--a laboratory which1 though in all ways modest1 is destined to be enduringly historical4 ,there was a wide table shelf running along the farther side1 in front of the two windows1 which were high1 and gave plenty of light4 ,in the centre was a stove2 on the left1 a small cabinet whose shelves held the small objects which the professor had been using4 ,there was a table in the left-hand corner2 and another small table--the one on which living bones were first photographed--was near the stove1 and a ,ruhmkorff coil was on the right4 ,the lesson of the laboratory was eloquent4 ,compared1 for instance1 with the elaborate1 expensive1 and complete apparatus of1 say1 the ,university of ,london1 or of any of the great ,american universities1 it was bare and unassuming to a degree4 ,it mutely said that in the great march of science it is the genius of man1 and not the perfection of appliances1 that breaks new ground in the great territory of the unknown4 ,it also caused one to wonder at and endeavour to imagine the great things which are to be done through elaborate appliances with the ,roentgen rays--a field in which the ,united ,states1 with its foremost genius in invention1 will very possibly1 if not probably1 take the lead--when the discoverer himself had done so much with so little4 ,already1 in a few weeks1 a skilled ,london operator1 ,mr4 ,a4 ,a4 ,c4 ,swinton1 has reduced the necessary time of exposure for ,roentgen photographs from fifteen minutes to four4 ,he used1 however1 a ,tesla oil coil1 discharged by twelve half-gallon ,leyden jars1 with an alternating current of twenty thousand volts' pressure4 ,here were no oil coils1 ,leyden jars1 or specially elaborate and expensive machines4 ,there were only a ,ruhmkorff coil and ,crookes 7vacuum7 tube and the man himself4 ,professor ,roentgen entered hurriedly1 something like an amiable gust of wind4 ,he is a tall1 slender1 and loose-limbed man1 whose whole appearance bespeaks enthusiasm and energy4 ,he wore a dark blue sack suit1 and his long1 dark hair stood straight up from his forehead1 as if he were permanently electrified by his own enthusiasm4 ,his voice is full and deep1 he speaks rapidly1 and1 altogether1 he seems clearly a man who1 once upon the track of a mystery which appealed to him1 would pursue it with unremitting vigor4 ,his eyes are kind1 quick1 and penetrating2 and there is no doubt that he much prefers gazing at a ,crookes tube to beholding a visitor1 visitors at present robbing him of much valued time4 ,the meeting was by appointment1 however1 and his greeting was cordial and hearty4 ,in addition to his own language he speaks ,french well and ,english scientifically1 which is different from speaking it popularly4 ,these three tongues being more or less within the equipment of his visitor1 the conversation proceeded on an international or polyglot basis1 so to speak1 varying at necessity's demand4 ,it transpired in the course of inquiry1 that the professor is a married man and fifty years of age1 though his eyes have the enthusiasm of twenty-five4 ,he was born near ,zurich1 and educated there1 and completed his studies and took his degree at ,utrecht4 ,he has been at ,wuerzburg about seven years1 and had made no discoveries which he considered of great importance prior to the one under consideration4 ,these details were given under good-natured protest1 he failing to understand why his personality should interest the public4 ,he declined to admire himself or his results in any degree1 and laughed at the idea of being famous4 ,the professor is too deeply interested in science to waste any time in thinking about himself4 ,his emperor had feasted1 flattered1 and decorated him1 and he was loyally grateful4 ,it was evident1 however1 that fame and applause had small attractions for him1 compared to the mysteries still hidden in the vacuum tubes of the other room4 ,now1 then1 said he1 smiling1 and with some impatience1 when the preliminary questions at which he chafed were over1 you have come to see the invisible rays4 ,is the invisible visible8 ,not to the eye2 but its results are4 ,come in here4 ,illustration3 ,,bones ,,of ,a ,,human ,,foot ,,photographed ,,through ,,the ,,flesh ,from a photograph by ,a4 ,a4 ,c4 ,swinton1 ,victoria ,street1 ,london4 ,exposure1 fifty-five seconds ,he led the way to the other square room mentioned1 and indicated the induction coil with which his researches were made1 an ordinary ,ruhmkorff coil1 with a spark of from four to six inches1 charged by a current of twenty amperes4 ,two wires led from the coil1 through an open door1 into a smaller room on the right4 ,in this room was a small table carrying a ,crookes tube connected with the coil4 ,the most striking object in the room1 however1 was a huge and mysterious tin box about seven feet high and four feet square4 ,it stood on end1 like a huge packing case1 its side being perhaps five inches from the ,crookes tube4 ,the professor explained the mystery of the tin box1 to the effect that it was a device of his own for obtaining a portable dark-room4 ,when he began his investigations he used the whole room1 as was shown by the heavy blinds and curtains so arranged as to exclude the entrance of all interfering light from the windows4 ,in the side of the tin box1 at the point immediately against the tube1 was a circular sheet of aluminum one millimetre in thickness1 and perhaps eighteen inches in diameter1 soldered to the surrounding tin4 ,to study his rays the professor had only to turn on the current1 enter the box1 close the door1 and in perfect darkness inspect only such light or light effects as he had a right to consider his own1 hiding his light1 in fact1 not under the ,biblical bushel1 but in a more commodious box4 ,step inside1 said he1 opening the door1 which was on the side of the box farthest from the tube4 ,i immediately did so1 not altogether certain whether my skeleton was to be photographed for general inspection1 or my secret thoughts held up to light on a glass plate4 ,you will find a sheet of barium paper on the shelf1 he added1 and then went away to the coil4 ,the door was closed1 and the interior of the box became black darkness4 ,the first thing ,i found was a wooden stool1 on which ,i resolved to sit4 ,then ,i found the shelf on the side next the tube1 and then the sheet of paper prepared with barium platinocyanide4 ,i was thus being shown the first phenomenon which attracted the discoverer's attention and led to his discovery1 namely1 the passage of rays1 themselves wholly invisible1 whose presence was only indicated by the effect they produced on a piece of sensitized photographic paper4 ,a moment later1 the black darkness was penetrated by the rapid snapping sound of the high-pressure current in action1 and ,i knew that the tube outside was glowing4 ,i held the sheet vertically on the shelf1 perhaps four inches from the plate4 ,there was no change1 however1 and nothing was visible4 ,do you see anything8 he called4 ,no4 ,the tension is not high enough2 and he proceeded to increase the pressure by operating an apparatus of mercury in long vertical tubes acted upon automatically by a weight lever which stood near the coil4 ,in a few moments the sound of the discharge again began1 and then ,i made my first acquaintance with the ,roentgen rays4 ,the moment the current passed1 the paper began to glow4 ,a yellowish green light spread all over its surface in clouds1 waves and flashes4 ,the yellow-green luminescence1 all the stranger and stronger in the darkness1 trembled1 wavered1 and floated over the paper1 in rhythm with the snapping of the discharge4 ,through the metal plate1 the paper1 myself1 and the tin box1 the invisible rays were flying1 with an effect strange1 interesting and uncanny4 ,the metal plate seemed to offer no appreciable resistance to the flying force1 and the light was as rich and full as if nothing lay between the paper and the tube4 ,put the book up1 said the professor4 ,i felt upon the shelf1 in the darkness1 a heavy book1 two inches in thickness1 and placed this against the plate4 ,it made no difference4 ,the rays flew through the metal and the book as if neither had been there1 and the waves of light1 rolling cloud-like over the paper1 showed no change in brightness4 ,it was a clear1 material illustration of the ease with which paper and wood are penetrated4 ,and then ,i laid book and paper down1 and put my eyes against the rays4 ,all was blackness1 and ,i neither saw nor felt anything4 ,the discharge was in full force1 and the rays were flying through my head1 and1 for all ,i knew1 through the side of the box behind me4 ,but they were invisible and impalpable4 ,they gave no sensation whatever4 ,whatever the mysterious rays may be1 they are not to be seen1 and are to be judged only by their works4 ,i was loath to leave this historical tin box1 but time pressed4 ,i thanked the professor1 who was happy in the reality of his discovery and the music of his sparks4 ,then ,i said3 ,where did you first photograph living bones8 ,here1 he said1 leading the way into the room where the coil stood4 ,he pointed to a table on which was another--the latter a small short-legged wooden one with more the shape and size of a wooden seat4 ,it was two feet square and painted coal black4 ,i viewed it with interest4 ,i would have bought it1 for the little table on which light was first sent through the human body will some day be a great historical curiosity2 but it was not for sale4 ,a photograph of it would have been a consolation1 but for several reasons one was not to be had at present4 ,however1 the historical table was there1 and was duly inspected4 ,how did you take the first hand photograph8 ,i asked4 ,the professor went over to a shelf by the window1 where lay a number of prepared glass plates1 closely wrapped in black paper4 ,he put a ,crookes tube underneath the table1 a few inches from the under side of its top4 ,then he laid his hand flat on the top of the table1 and placed the glass plate loosely on his hand4 ,you ought to have your portrait painted in that attitude1 ,i suggested4 ,no1 that is nonsense1 said he1 smiling4 ,or be photographed4 ,this suggestion was made with a deeply hidden purpose4 ,the rays from the ,roentgen eyes instantly penetrated the deeply hidden purpose4 ,oh1 no1 said he2 ,i can't let you make pictures of me4 ,i am too busy4 ,clearly the professor was entirely too modest to gratify the wishes of the curious world4 ,now1 ,professor1 said ,i1 will you tell me the history of the discovery8 ,there is no history1 he said4 ,i have been for a long time interested in the problem of the cathode rays from a vacuum tube as studied by ,hertz and ,lenard4 ,i had followed their and other researches with great interest1 and determined1 as soon as ,i had the time1 to make some researches of my own4 ,this time ,i found at the close of last ,october4 ,i had been at work for some days when ,i discovered something new4 ,what was the date8 ,the eighth of ,november4 ,and what was the discovery8 ,i was working with a ,crookes tube covered by a shield of black cardboard4 ,a piece of barium platinocyanide paper lay on the bench there4 ,i had been passing a current through the tube1 and ,i noticed a peculiar black line across the paper4 ,what of that8 ,the effect was one which could only be produced1 in ordinary parlance1 by the passage of light4 ,no light could come from the tube1 because the shield which covered it was impervious to any light known1 even that of the electric arc4 ,and what did you think8 ,i did not think2 ,i investigated4 ,i assumed that the effect must have come from the tube1 since its character indicated that it could come from nowhere else4 ,i tested it4 ,in a few minutes there was no doubt about it4 ,rays were coming from the tube which had a luminescent effect upon the paper4 ,i tried it successfully at greater and greater distances1 even at two metres4 ,it seemed at first a new kind of invisible light4 ,it was clearly something new1 something unrecorded4 ,is it light8 ,no4 ,is it electricity8 ,not in any known form4 ,what is it8 ,i don't know4 ,and the discoverer of the ,x rays thus stated as calmly his ignorance of their essence as has everybody else who has written on the phenomena thus far4 ,having discovered the existence of a new kind of rays1 ,i of course began to investigate what they would do4 ,he took up a series of cabinet-sized photographs4 ,it soon appeared from tests that the rays had penetrative powers to a degree hitherto unknown4 ,they penetrated paper1 wood1 and cloth with ease2 and the thickness of the substance made no perceptible difference1 within reasonable limits4 ,he showed photographs of a box of laboratory weights of platinum1 aluminum1 and brass1 they and the brass hinges all having been photographed from a closed box1 without any indication of the box4 ,also a photograph of a coil of fine wire1 wound on a wooden spool1 the wire having been photographed1 and the wood omitted4 ,the rays1 he continued1 passed through all the metals tested1 with a facility varying1 roughly speaking1 with the density of the metal4 ,these phenomena ,i have discussed carefully in my report to the ,wuerzburg society1 and you will find all the technical results therein stated4 ,he showed a photograph of a small sheet of zinc4 ,this was composed of smaller plates soldered laterally with solders of different metallic proportions4 ,the differing lines of shadow1 caused by the difference in the solders1 were visible evidence that a new means of detecting flaws and chemical variations in metals had been found4 ,a photograph of a compass showed the needle and dial taken through the closed brass cover4 ,the markings of the dial were in red metallic paint1 and thus interfered with the rays1 and were reproduced4 ,since the rays had this great penetrative power1 it seemed natural that they should penetrate flesh1 and so it proved in photographing the hand1 as ,i showed you4 ,a detailed discussion of the characteristics of his rays the professor considered unprofitable and unnecessary4 ,he believes1 though1 that these mysterious radiations are not light1 because their behaviour is essentially different from that of light rays1 even those light rays which are themselves invisible4 ,the ,roentgen rays cannot be reflected by reflecting surfaces1 concentrated by lenses1 or refracted or diffracted4 ,they produce photographic action on a sensitive film1 but their action is weak as yet1 and herein lies the first important field of their development4 ,the professor's exposures were comparatively long--an average of fifteen minutes in easily penetrable media1 and half an hour or more in photographing the bones of the hand4 ,concerning vacuum tubes1 he said that he preferred the ,hittorf1 because it had the most perfect vacuum1 the highest degree of air exhaustion being the consummation most desirable4 ,in answer to a question1 ,what of the future8 he said3 ,i am not a prophet1 and ,i am opposed to prophesying4 ,i am pursuing my investigations1 and as fast as my results are verified ,i shall make them public4 ,do you think the rays can be so modified as to photograph the organs of the human body8 ,in answer he took up the photograph of the box of weights4 ,here are already modifications1 he said1 indicating the various degrees of shadow produced by the aluminum1 platinum1 and brass weights1 the brass hinges1 and even the metallic stamped lettering on the cover of the box1 which was faintly perceptible4 ,but ,professor ,neusser has already announced that the photographing of the various organs is possible4 ,we shall see what we shall see1 he said4 ,we have the start now2 the development will follow in time4 ,you know the apparatus for introducing the electric light into the stomach8 ,yes4 ,do you think that this electric light will become a vacuum tube for photographing1 from the stomach1 any part of the abdomen or thorax8 ,the idea of swallowing a ,crookes tube1 and sending a high frequency current down into one's stomach1 seemed to him exceedingly funny4 ,when ,i have done it1 ,i will tell you1 he said1 smiling1 resolute in abiding by results4 ,there is much to do1 and ,i am busy1 very busy1 he said in conclusion4 ,he extended his hand in farewell1 his eyes already wandering toward his work in the inside room4 ,and his visitor promptly left him2 the words1 ,i am busy1 said in all sincerity1 seeming to describe in a single phrase the essence of his character and the watchword of a very unusual man4 ,returning by way of ,berlin1 ,i called upon ,herr ,spies of the ,urania1 whose photographs after the ,roentgen method were the first made public1 and have been the best seen thus far4 ,in speaking of the discovery he said3 ,i applied it1 as soon as the penetration of flesh was apparent1 to the photograph of a man's hand4 ,something in it had pained him for years1 and the photograph at once exhibited a small foreign object1 as you can see2 and he exhibited a copy of the photograph in question4 ,the speck there is a small piece of glass1 which was immediately extracted1 and which1 in all probability1 would have otherwise remained in the man's hand to the end of his days4 ,all of which indicates that the needle which has pursued its travels in so many persons1 through so many years1 will be suppressed by the camera4 ,my next object is to photograph the bones of the entire leg1 continued ,herr ,spies4 ,i anticipate no difficulty1 though it requires some thought in manipulation4 ,it will be seen that the ,roentgen rays and their marvellous practical possibilities are still in their infancy4 ,the first successful modification of the action of the rays so that the varying densities of bodily organs will enable them to be photographed will bring all such morbid growths as tumours and cancers into the photographic field1 to say nothing of vital organs which may be abnormally developed or degenerate4 ,how much this means to medical and surgical practice it requires little imagination to conceive4 ,diagnosis1 long a painfully uncertain science1 has received an unexpected and wonderful assistant2 and how greatly the world will benefit thereby1 how much pain will be saved1 only the future can determine4 ,in science a new door has been opened where none was known to exist1 and a side-light on phenomena has appeared1 of which the results may prove as penetrating and astonishing as the ,roentgen rays themselves4 ,the most agreeable feature of the discovery is the opportunity it gives for other hands to help2 and the work of these hands will add many new words to the dictionaries1 many new facts to science1 and1 in the years long ahead of us1 fill many more volumes than there are paragraphs in this brief and imperfect account4 ,,the ,,wireless ,,telegraph ,,george ,,iles ,from ,flame1 ,electricity and the ,camera1 copyright by ,doubleday1 ,page ,co41 ,new ,york4 ,in a series of experiments interesting enough but barren of utility1 the water of a canal1 river1 or bay has often served as a conductor for the telegraph4 ,among the electricians who have thus impressed water into their service was ,professor ,morse4 ,in #ahdb he sent a few signals across the channel from ,castle ,garden1 ,new ,york1 to ,governor's ,island1 a distance of a mile4 ,with much better results1 he sent messages1 later in the same year1 from one side of the canal at ,washington to the other1 a distance of eighty feet1 employing large copper plates at each terminal4 ,the enormous current required to overcome the resistance of water has barred this method from practical adoption4 ,we pass1 therefore1 to electrical communication as effected by induction--the influence which one conductor exerts on another through an intervening insulator4 ,at the outset we shall do well to bear in mind that magnetic phenomena1 which are so closely akin to electrical1 are always inductive4 ,to observe a common example of magnetic induction1 we have only to move a horseshoe magnet in the vicinity of a compass needle1 which will instantly sway about as if blown hither and thither by a sharp draught of air4 ,this action takes place if a slate1 a pane of glass1 or a shingle is interposed between the needle and its perturber4 ,there is no known insulator for magnetism1 and an induction of this kind exerts itself perceptibly for many yards when large masses of iron are polarised1 so that the derangement of compasses at sea from moving iron objects aboard ship1 or from ferric ores underlying a sea-coast1 is a constant peril to the mariner4 ,electrical conductors behave much like magnetic masses4 ,a current conveyed by a conductor induces a counter-current in all surrounding bodies1 and in a degree proportioned to their conductive power4 ,this effect is1 of course1 greatest upon the bodies nearest at hand1 and we have already remarked its serious retarding effect in ocean telegraphy4 ,when the original current is of high intensity1 it can induce a perceptible current in another wire at a distance of several miles4 ,in #ahdb ,henry remarked that electric waves had this quality1 but in that early day of electrical interpretation the full significance of the fact eluded him4 ,in the top room of his house he produced a spark an inch long1 which induced currents in wires stretched in his cellar1 through two thick floors and two rooms which came between4 ,induction of this sort causes the annoyance1 familiar in single telephonic circuits1 of being obliged to overhear other subscribers1 whose wires are often far away from our own4 ,the first practical use of induced currents in telegraphy was when ,mr4 ,edison1 in #ahhe1 enabled the trains on a line of the ,staten ,island ,railroad to be kept in constant communication with a telegraphic wire1 suspended in the ordinary way beside the track4 ,the roof of a car was of insulated metal1 and every tap of an operator's key within the walls electrified the roof just long enough to induce a brief pulse through the telegraphic circuit4 ,in sending a message to the car this wire was1 moment by moment1 electrified1 inducing a response first in the car roof1 and next in the sounder beneath it4 ,this remarkable apparatus1 afterward used on the ,lehigh ,valley ,railroad1 was discontinued from lack of commercial support1 although it would seem to be advantageous to maintain such a service on other than commercial grounds4 ,in case of chance obstructions on the track1 or other peril1 to be able to communicate at any moment with a train as it speeds along might mean safety instead of disaster4 ,the chief item in the cost of this system is the large outlay for a special telegraphic wire4 ,the next electrician to employ induced currents in telegraphy was ,mr4 7now ,sir7 ,william ,h4 ,preece1 the engineer then at the head of the ,british telegraph system4 ,let one example of his work be cited4 ,in #ahif a cable was laid between ,lavernock1 near ,cardiff1 on the ,bristol ,channel1 and ,flat ,holme1 an island three and a third miles off4 ,as the channel at this point is a much-frequented route and anchor ground1 the cable was broken again and again4 ,as a substitute for it ,mr4 ,preece1 in #ahih1 strung wires along the opposite shores1 and found that an electric pulse sent through one wire instantly made itself heard in a telephone connected with the other4 ,it would seem that in this etheric form of telegraphy the two opposite lines of wire must be each as long as the distance which separates them2 therefore1 to communicate across the ,english ,channel from ,dover to ,calais would require a line along each coast at least twenty miles in length4 ,where such lines exist for ordinary telegraphy1 they might easily lend themselves to the ,preece system of signalling in case a submarine cable were to part4 ,marconi1 adopting electrostatic instead of electro-magnetic waves1 has won striking results4 ,let us note the chief of his forerunners1 as they prepared the way for him4 ,in #ahfd ,maxwell observed that electricity and light have the same velocity1 #ahf1djj miles a second1 and he formulated the theory that electricity propagates itself in waves which differ from those of light only in being longer4 ,this was proved to be true by ,hertz1 who in #ahhh showed that where alternating currents of very high frequency were set up in an open circuit1 the energy might be conveyed entirely away from the circuit into the surrounding space as electric waves4 ,his detector was a nearly closed circle of wire1 the ends being soldered to metal balls almost in contact4 ,with this simple apparatus he demonstrated that electric waves move with the speed of light1 and that they can be reflected and refracted precisely as if they formed a visible beam4 ,at a certain intensity of strain the air insulation broke down1 and the air became a conductor4 ,this phenomenon of passing quite suddenly from a non-conductive to a conductive state is1 as we shall duly see1 also to be noted when air or other gases are exposed to the ,x ray4 ,now for the effect of electric waves such as ,hertz produced1 when they impinge upon substances reduced to powder or filings4 ,conductors1 such as the metals1 are of inestimable service to the electrician2 of equal value are non-conductors1 such as glass and gutta-percha1 as they strictly fence in an electric stream4 ,a third and remarkable vista opens to experiment when it deals with substances which1 in their normal state1 are non-conductive1 but which1 agitated by an electric wave1 instantly become conductive in a high degree4 ,as long ago as #ahff ,mr4 ,s4 ,a4 ,varley noticed that black lead1 reduced to a loose dust1 effectually intercepted a current from fifty ,daniell cells1 although the battery poles were very near each other4 ,when he increased the electric tension four- to six-fold1 the black-lead particles at once compacted themselves so as to form a bridge of excellent conductivity4 ,on this principle he invented a lightning-protector for electrical instruments1 the incoming flash causing a tiny heap of carbon dust to provide it with a path through which it could safely pass to the earth4 ,professor ,temistocle ,calzecchi ,onesti of ,fermo1 in #ahhe1 in an independent series of researches1 discovered that a mass of powdered copper is a non-conductor until an electric wave beats upon it2 then1 in an instant1 the mass resolves itself into a conductor almost as efficient as if it were a stout1 unbroken wire4 ,professor ,edouard ,branly of ,paris1 in #ahia1 on this principle devised a coherer1 which passed from resistance to invitation when subjected to an electric impulse from afar4 ,he enhanced the value of his device by the vital discovery that the conductivity bestowed upon filings by electric discharges could be destroyed by simply shaking or tapping them apart4 ,in a homely way the principle of the coherer is often illustrated in ordinary telegraphic practice4 ,an operator notices that his instrument is not working well1 and he suspects that at some point in his circuit there is a defective contact4 ,a little dirt1 or oxide1 or dampness1 has come in between two metallic surfaces2 to be sure1 they still touch each other1 but not in the firm and perfect way demanded for his work4 ,accordingly he sends a powerful current abruptly into the line1 which clears its path thoroughly1 brushes aside dirt1 oxide1 or moisture1 and the circuit once more is as it should be4 ,in all likelihood1 the coherer is acted upon in the same way4 ,among the physicists who studied it in its original form was ,dr4 ,oliver ,j4 ,lodge4 ,he improved it so much that1 in #ahid1 at the ,royal ,institution in ,london1 he was able to show it as an electric eye that registered the impact of invisible rays at a distance of more than forty yards4 ,he made bold to say that this distance might be raised to half a mile4 ,as early as #ahgi ,professor ,d4 ,e4 ,hughes began a series of experiments in wireless telegraphy1 on much the lines which in other hands have now reached commercial as well as scientific success4 ,professor ,hughes was the inventor of the microphone1 and that instrument1 he declared1 affords an unrivalled means of receiving wireless messages1 since it requires no tapping to restore its non-conductivity4 ,in his researches this investigator was convinced that his signals were propagated1 not by electro-magnetic induction1 but by aerial electric waves spreading out from an electric spark4 ,early in #ahhj he showed his apparatus to ,professor ,stokes1 who observed its operation carefully4 ,his dictum was that he saw nothing which could not be explained by known electro-magnetic effects4 ,this erroneous judgment so discouraged ,professor ,hughes that he desisted from following up his experiments1 and thus1 in all probability1 the birth of the wireless telegraph was for several years delayed4#c ,illustration3 ,fig4 #ga4--,marconi coherer1 enlarged view ,the coherer1 as improved by ,marconi1 is a glass tube about one and one-half inches long and about one-twelfth of an inch in internal diameter4 ,the electrodes are inserted in this tube so as almost to touch2 between them is about one-thirtieth of an inch filled with a pinch of the responsive mixture which forms the pivot of the whole contrivance4 ,this mixture is #ij per cent4 nickel filings1 #aj per cent4 hard silver filings1 and a mere trace of mercury2 the tube is exhausted of air to within one ten-thousandth part 7,fig4 #ga74 ,how does this trifle of metallic dust manage loudly to utter its signals through a telegraphic sounder1 or forcibly indent them upon a moving strip of paper8 ,not directly1 but indirectly1 as the very last refinement of initiation4 ,let us imagine an ordinary telegraphic battery strong enough loudly to tick out a message4 ,be it ever so strong it remains silent until its circuit is completed1 and for that completion the merest touch suffices4 ,now the thread of dust in the coherer forms part of such a telegraphic circuit3 as loose dust it is an effectual bar and obstacle1 under the influence of electric waves from afar it changes instantly to a coherent metallic link which at once completes the circuit and delivers the message4 ,an electric impulse1 almost too attenuated for computation1 is here able to effect such a change in a pinch of dust that it becomes a free avenue instead of a barricade4 ,through that avenue a powerful blow from a local store of energy makes itself heard and felt4 ,no device of the trigger class is comparable with this in delicacy4 ,an instant after a signal has taken its way through the coherer a small hammer strikes the tiny tube1 jarring its particles asunder1 so that they resume their normal state of high resistance4 ,we may well be astonished at the sensitiveness of the metallic filings to an electric wave originating many miles away1 but let us remember how clearly the eye can see a bright lamp at the same distance as it sheds a sister beam4 ,thus far no substance has been discovered with a mechanical responsiveness to so feeble a ray of light2 in the world of nature and art the coherer stands alone4 ,the electric waves employed by ,marconi are about four feet long1 or have a frequency of about #bej1jjj1jjj per second4 ,such undulations pass readily through brick or stone walls1 through common roofs and floors--indeed1 through all substances which are non-conductive to electric waves of ordinary length4 ,were the energy of a ,marconi sending-instrument applied to an arc-lamp1 it would generate a beam of a thousand candle-power4 ,we have thus a means of comparing the sensitiveness of the retina to light with the responsiveness of the ,marconi coherer to electric waves1 after both radiations have undergone a journey of miles4 ,an essential feature of this method of etheric telegraphy1 due to ,marconi himself1 is the suspension of a perpendicular wire at each terminus1 its length twenty feet for stations a mile apart1 forty feet for four miles1 and so on1 the telegraphic distance increasing as the square of the length of suspended wire4 ,in the ,kingstown regatta1 ,july1 #ahih1 ,marconi sent from a yacht under full steam a report to the shore without the loss of a moment from start to finish4 ,this feat was repeated during the protracted contest between the ,columbia and the ,shamrock yachts in ,new ,york ,bay1 ,october1 #ahii4 ,on ,march #bh1 #ahii1 ,marconi signals put ,wimereux1 two miles north of ,boulogne1 in communication with the ,south ,foreland ,lighthouse1 thirty-two miles off4#d ,in ,august1 #ahii1 during the manoeuvres of the ,british navy1 similar messages were sent as far as eighty miles4 ,it was clearly demonstrated that a new power had been placed in the hands of a naval commander4 ,a touch on a button in a flagship is all that is now needed to initiate every tactical evolution in a fleet1 and insure an almost automatic precision in the resulting movements of the ships4 ,the flashing lantern is superseded at night1 flags and the semaphore by day1 or1 if these are retained1 it is for services purely auxiliary4 ,the hideous and bewildering shrieks of the steam-siren need no longer be heard in a fog1 and the uncertain system of gun signals will soon become a thing of the past4 ,the interest of the naval and military strategist in the ,marconi apparatus extends far beyond its communication of intelligence4 ,any electrical appliance whatever may be set in motion by the same wave that actuates a telegraphic sounder4 ,a fuse may be ignited1 or a motor started and directed1 by apparatus connected with the coherer1 for all its minuteness4 ,mr4 ,walter ,jamieson and ,mr4 ,john ,trotter have devised means for the direction of torpedoes by ether waves1 such as those set at work in the wireless telegraph4 ,two rods projecting above the surface of the water receive the waves1 and are in circuit with a coherer and a relay4 ,at the will of the distant operator a hollow wire coil bearing a current draws in an iron core either to the right or to the left1 moving the helm accordingly4 ,as the news of the success of the ,marconi telegraph made its way to the ,london ,stock ,exchange there was a fall in the shares of cable companies4 ,the fear of rivalry from the new invention was baseless4 ,as but fifteen words a minute are transmissible by the ,marconi system1 it evidently does not compete with a cable1 such as that between ,france and ,england1 which can transmit #b1ejj words a minute without difficulty4 ,the ,marconi telegraph comes less as a competitor to old systems than as a mode of communication which creates a field of its own4 ,we have seen what it may accomplish in war1 far outdoing any feat possible to other apparatus1 acoustic1 luminous1 or electrical4 ,in quite as striking fashion does it break new ground in the service of commerce and trade4 ,it enables lighthouses continually to spell their names1 so that receivers aboard ship may give the steersmen their bearings even in storm and fog4 ,in the crowded condition of the steamship lanes which cross the ,atlantic1 a priceless security against collision is afforded the man at the helm4 ,on ,november #ae1 #ahii1 ,marconi telegraphed from the ,american liner ,st4 ,paul to the ,needles1 sixty-six nautical miles away4 ,on ,december #aa and #ab1 #aija1 he received wireless signals near ,st4 ,john's1 ,newfoundland1 sent from ,poldhu1 ,cornwall1 ,england1 or a distance of #a1hjj miles1--a feat which astonished the world4 ,in many cases the telegraphic business to an island is too small to warrant the laying of a cable2 hence we find that ,trinidad and ,tobago are to be joined by the wireless system1 as also five islands of the ,hawaiian group1 eight to sixty-one miles apart4 ,a weak point in the first ,marconi apparatus was that anybody within the working radius of the sending-instrument could read its messages4 ,to modify this objection secret codes were at times employed1 as in commerce and diplomacy4 ,a complete deliverance from this difficulty is promised in attuning a transmitter and a receiver to the same note1 so that one receiver1 and no other1 shall respond to a particular frequency of impulses4 ,the experiments which indicate success in this vital particular have been conducted by ,professor ,lodge4 ,when electricians1 twenty years ago1 committed energy to a wire and thus enabled it to go round a corner1 they felt that they had done well4 ,the ,hertz waves sent abroad by ,marconi ask no wire1 as they find their way1 not round a corner1 but through a corner4 ,on ,may #a1 #ahii1 a party of ,french officers on board the ,ibis at ,sangatte1 near ,calais1 spoke to ,wimereux by means of a ,marconi apparatus1 with ,cape ,grisnez1 a lofty promontory1 intervening4 ,in ascertaining how much the earth and the sea may obstruct the waves of ,hertz there is a broad and fruitful field for investigation4 ,it may be1 says ,professor ,john ,trowbridge1 that such long electrical waves roll around the surface of such obstructions very much as waves of sound and of water would do4 ,illustration3 ,fig4 #gc--;,discontinuous electric waves ,illustration3 ,fig4 #gd--,wehnelt interrupter ,it is singular how discoveries sometimes arrive abreast of each other so as to render mutual aid1 or supply a pressing want almost as soon as it is felt4 ,the coherer in its present form is actuated by waves of comparatively low frequency1 which rise from zero to full height in extremely brief periods1 and are separated by periods decidedly longer 7,fig4 #gc74 ,what is needed is a plan by which the waves may flow either continuously or so near together that they may lend themselves to attuning4 ,dr4 ,wehnelt1 by an extraordinary discovery1 may1 in all likelihood1 provide the lacking device in the form of his interrupter1 which breaks an electric circuit as often as two thousand times a second4 ,the means for this amazing performance are simplicity itself 7,fig4 #gd74 ,a jar1 a1 containing a solution of sulphuric acid has two electrodes immersed in it2 one of them is a lead plate of large surface1 b2 the other is a small platinum wire which protrudes from a glass tube1 d4 ,a current passing through the cell between the two metals at c is interrupted1 in ordinary cases five hundred times a second1 and in extreme cases four times as often1 by bubbles of gas given off from the wire instant by instant4 ,,footnotes3 #c ,history of the ,wireless ,telegraph1 by ,j4 ,j4 ,fahie4 ,edinburgh and ,london1 ,william ,blackwood ,sons2 ,new ,york1 ,dodd1 ,mead ,co41 #ahii4 ,this work is full of interesting detail1 well illustrated4 #d ,the value of wireless telegraphy in relation to disasters at sea was proved in a remarkable way yesterday morning4 ,while the ,channel was enveloped in a dense fog1 which had lasted throughout the greater part of the night1 the ,east ,goodwin ,lightship had a very narrow escape from sinking at her moorings by being run into by the steamship ,r4 ,f4 ,matthews1 #a1ifd tons gross burden1 of ,london1 outward bound from the ,thames4 ,the ,east ,goodwin ,lightship is one of four such vessels marking the ,goodwin ,sands1 and1 curiously enough1 it happens to be the one ship which has been fitted out with ,signor ,marconi's installation for wireless telegraphy4 ,the vessel was moored about twelve miles to the northeast of the ,south ,foreland ,lighthouse 7where there is another wireless-telegraphy installation71 and she is about ten miles from the shore1 being directly opposite ,deal4 ,the information regarding the collision was at once communicated by wireless telegraphy from the disabled lightship to the ,south ,foreland ,lighthouse1 where ,mr4 ,bullock1 assistant to ,signor ,marconi1 received the following message3 ,we have just been run into by the steamer ,r4 ,f4 ,matthews of ,london4 ,steamship is standing by us4 ,our bows very badly damaged4 ,mr4 ,bullock immediately forwarded this information to the ,trinity ,house authorities at ,ramsgate4--,times1 ,april #bi1 #ahii4 ,,electricity1 ,,what ,,its ,,mastery ,,means3 ,,with ,a ,,review ,,and ,a ,,prospect ,,george ,,iles ,from ,flame1 ,electricity and the ,camera1 copyright by ,doubleday1 ,page ,co41 ,new ,york4 ,with the mastery of electricity man enters upon his first real sovereignty of nature4 ,as we hear the whirr of the dynamo or listen at the telephone1 as we turn the button of an incandescent lamp or travel in an electromobile1 we are partakers in a revolution more swift and profound than has ever before been enacted upon earth4 ,until the nineteenth century fire was justly accounted the most useful and versatile servant of man4 ,to-day electricity is doing all that fire ever did1 and doing it better1 while it accomplishes uncounted tasks far beyond the reach of flame1 however ingeniously applied4 ,we may thus observe under our eyes just such an impetus to human intelligence and power as when fire was first subdued to the purposes of man1 with the immense advantage that1 whereas the subjugation of fire demanded ages of weary and uncertain experiment1 the mastery of electricity is1 for the most part1 the assured work of the nineteenth century1 and1 in truth1 very largely of its last three decades4 ,the triumphs of the electrician are of absorbing interest in themselves1 they bear a higher significance to the student of man as a creature who has gradually come to be what he is4 ,in tracing the new horizons won by electric science and art1 a beam of light falls on the long and tortuous paths by which man rose to his supremacy long before the drama of human life had been chronicled or sung4 ,of the strides taken by humanity on its way to the summit of terrestrial life1 there are but four worthy of mention as preparing the way for the victories of the electrician--the attainment of the upright attitude1 the intentional kindling of fire1 the maturing of emotional cries to articulate speech1 and the invention of written symbols for speech4 ,as we examine electricity in its fruitage we shall find that it bears the unfailing mark of every other decisive factor of human advance3 its mastery is no mere addition to the resources of the race1 but a multiplier of them4 ,the case is not as when an explorer discovers a plant hitherto unknown1 such as ,indian corn1 which takes its place beside rice and wheat as a new food1 and so measures a service which ends there4 ,nor is it as when a prospector comes upon a new metal1 such as nickel1 with the sole effect of increasing the variety of materials from which a smith may fashion a hammer or a blade4 ,almost infinitely higher is the benefit wrought when energy in its most useful phase is1 for the first time1 subjected to the will of man1 with dawning knowledge of its unapproachable powers4 ,it begins at once to marry the resources of the mechanic and the chemist1 the engineer and the artist1 with issue attested by all its own fertility1 while its rays reveal province after province undreamed of1 and indeed unexisting1 before its advent4 ,every other primal gift of man rises to a new height at the bidding of the electrician4 ,all the deftness and skill that have followed from the upright attitude1 in its creation of the human hand1 have been brought to a new edge and a broader range through electric art4 ,between the uses of flame and electricity have sprung up alliances which have created new wealth for the miner and the metal-worker1 the manufacturer and the shipmaster1 with new insights for the man of research4 ,articulate speech borne on electric waves makes itself heard half-way across ,america1 and words reduced to the symbols of symbols--expressed in the perforations of a strip of paper--take flight through a telegraph wire at twenty-fold the pace of speech4 ,because the latest leap in knowledge and faculty has been won by the electrician1 he has widened the scientific outlook vastly more than any explorer who went before4 ,beyond any predecessor1 he began with a better equipment and a larger capital to prove the gainfulness which ever attends the exploiting a supreme agent of discovery4 ,as we trace a few of the unending interlacements of electrical science and art with other sciences and arts1 and study their mutually stimulating effects1 we shall be reminded of a series of permutations where the latest of the factors1 because latest1 multiplies all prior factors in an unexampled degree4#e ,we shall find reason to believe that this is not merely a suggestive analogy1 but really true as a tendency1 not only with regard to man's gains by the conquest of electricity1 but also with respect to every other signal victory which has brought him to his present pinnacle of discernment and rule4 ,if this permutative principle in former advances lay undetected1 it stands forth clearly in that latest accession to skill and interpretation which has been ushered in by ,franklin and ,volta1 ,faraday and ,henry4 ,although of much less moment than the triumphs of the electrician1 the discovery of photography ranks second in importance among the scientific feats of the nineteenth century4 ,the camera is an artificial eye with almost every power of the human retina1 and with many that are denied to vision--however ingeniously fortified by the lens-maker4 ,a brief outline of photographic history will show a parallel to the permutative impulse so conspicuous in the progress of electricity4 ,at the points where the electrician and the photographer collaborate we shall note achievements such as only the loftiest primal powers may evoke4 ,a brief story of what electricity and its necessary precursor1 fire1 have done and promise to do for civilization1 may have attraction in itself2 so1 also1 may a review1 though most cursory1 of the work of the camera and all that led up to it3 for the provinces here are as wide as art and science1 and their bounds comprehend well-nigh the entirety of human exploits4 ,and between the lines of this story we may read another--one which may tell us something of the earliest stumblings in the dawn of human faculty4 ,when we compare man and his next of kin1 we find between the two a great gulf1 surely the widest betwixt any allied families in nature4 ,can a being of intellect1 conscience1 and aspiration have sprung at any time1 however remote1 from the same stock as the orang and the chimpanzee8 ,since #ahei1 when ,darwin published his ,origin of ,species1 the theory of evolution has become so generally accepted that to-day it is little more assailed than the doctrine of gravitation4 ,and yet1 while the average man of intelligence bows to the formula that all which now exists has come from the simplest conceivable state of things1--a universal nebula1 if you will1--in his secret soul he makes one exception--himself4 ,that there is a great deal more assent than conviction in the world is a chiding which may come as justly from the teacher's table as from the preacher's pulpit4 ,now1 if we but catch the meaning of man's mastery of electricity1 we shall have light upon his earlier steps as a fire-kindler1 and as a graver of pictures and symbols on bone and rock4 ,as we thus recede from civilization to primeval savagery1 the process of the making of man may become so clear that the arguments of ,darwin shall be received with conviction1 and not with silent repulse4 ,as we proceed to recall1 one by one1 the salient chapters in the history of fire1 and of the arts of depiction that foreran the camera1 we shall perceive a truth of high significance4 ,we shall see that1 while every new faculty has its roots deep in older powers1 and while its growth may have been going on for age after age1 yet its flowering may be as the event of a morning4 ,even as our gardens show us the century-plants1 once supposed to bloom only at the end of a hundred years1 so history1 in the large1 exhibits discoveries whose harvests are gathered only after the lapse of aeons instead of years4 ,the arts of fire were slowly elaborated until man had produced the crucible and the still1 through which his labours culminated in metals purified1 in acids vastly more corrosive than those of vegetation1 in glass and porcelain equally resistant to flame and the electric wave4 ,these were combined in an hour by ,volta to build his cell1 and in that hour began a new era for human faculty and insight4 ,it is commonly imagined that the progress of humanity has been at a tolerably uniform pace4 ,our review of that progress will show that here and there in its course have been leaps1 as radically new forces have been brought under the dominion of man4 ,we of the electric revolution are sharply marked off from our great-grandfathers1 who looked upon the cell of ,volta as a curious toy4 ,they1 in their turn1 were profoundly differenced from the men of the seventeenth century1 who had not learned that flame could outvie the horse as a carrier1 and grind wheat better than the mill urged by the breeze4 ,and nothing short of an abyss stretches between these men and their remote ancestors1 who had not found a way to warm their frosted fingers or lengthen with lamp or candle the short1 dark days of winter4 ,throughout the pages of this book there will be some recital of the victories won by the fire-maker1 the electrician1 the photographer1 and many more in the peerage of experiment and research4 ,underlying the sketch will appear the significant contrast betwixt accessions of minor and of supreme dignity4 ,the finding a new wood1 such as that of the yew1 means better bows for the archer1 stronger handles for the tool-maker2 the subjugation of a universal force such as fire1 or electricity1 stands for the exaltation of power in every field of toil1 for the creation of a new earth for the worker1 new heavens for the thinker4 ,as a corollary1 we shall observe that an increasing width of gap marks off the successive stages of human progress from each other1 so that its latest stride is much the longest and most decisive4 ,and it will be further evident that1 while every new faculty is of age-long derivation from older powers and ancient aptitudes1 it nevertheless comes to the birth in a moment1 as it were1 and puts a strain of probably fatal severity on those contestants who miss the new gift by however little4 ,we shall1 therefore1 find that the principle of permutation1 here merely indicated1 accounts in large measure for three cardinal facts in the history of man3 ,first1 his leaps forward2 second1 the constant accelerations in these leaps2 and third1 the gap in the record of the tribes which1 in the illimitable past1 have succumbed as forces of a new edge and sweep have become engaged in the fray4#f ,the interlacements of the arts of fire and of electricity are intimate and pervasive4 ,while many of the uses of flame date back to the dawn of human skill1 many more have become of new and higher value within the last hundred years4 ,fire to-day yields motive power with tenfold the economy of a hundred years ago1 and motive power thus derived is the main source of modern electric currents4 ,in metallurgy there has long been an unwitting preparation for the advent of the electrician1 and here the services of fire within the nineteenth century have won triumphs upon which the later successes of electricity largely proceed4 ,in producing alloys1 and in the singular use of heat to effect its own banishment1 novel and radical developments have been recorded within the past decade or two4 ,these1 also1 make easier and bolder the electrician's tasks4 ,the opening chapters of this book will1 therefore1 bestow a glance at the principal uses of fire as these have been revealed and applied4 ,this glance will make clear how fire and electricity supplement each other with new and remarkable gains1 while in other fields1 not less important1 electricity is nothing else than a supplanter of the very force which made possible its own discovery and impressment4 ,here follow chapters which outline the chief applications of flame and of electricity4 ,let us compare electricity with its precursor1 fire1 and we shall understand the revolution by which fire is now in so many tasks supplanted by the electric pulse which1 the while1 creates for itself a thousand fields denied to flame4 ,copper is an excellent thermal conductor1 and yet it transmits heat almost infinitely more slowly than it conveys electricity4 ,one end of a thick copper rod ten feet long may be safely held in the hand while the other end is heated to redness1 yet one millionth part of this same energy1 if in the form of electricity1 would traverse the rod in one #ajj1jjj1jjjth part of a second4 ,compare next electricity with light1 often the companion of heat4 ,light travels in straight lines only2 electricity can go round a corner every inch for miles1 and1 none the worse1 yield a brilliant beam at the end of its journey4 ,indirectly1 therefore1 electricity enables us to conduct either heat or light as if both were flexible pencils of rays1 and subject to but the smallest tolls in their travel4 ,we have remarked upon such methods as those of the electric welder which summon intense heat without fire1 and we have glanced at the electric lamps which shine just because combustion is impossible through their rigid exclusion of air4 ,then for a moment we paused to look at the plating baths which have developed themselves into a commanding rivalry with the blaze of the smelting furnace1 with the flame which from time immemorial has filled the ladle of the founder and moulder4 ,thus methods that commenced in dismissing flame end boldly by dispossessing heat itself4 ,but1 it may be said1 this usurping electricity usually finds its source1 after all1 in combustion under a steam-boiler4 ,true1 but mark the harnessing of ,niagara1 of the ,lachine ,rapids near ,montreal1 of a thousand streams elsewhere4 ,in the near future motive power of ,nature's giving is to be wasted less and less1 and perforce will more and more exclude heat from the chain of transformations which issue in the locomotive's flight1 in the whirl of factory and mill4 ,thus in some degree is allayed the fear1 never well grounded1 that when the coal fields of the globe are spent civilization must collapse4 ,as the electrician hears this foreboding he recalls how much fuel is wasted in converting heat into electricity4 ,he looks beyond either turbine or shaft turned by wind or tide1 and1 remembering that the metal dissolved in his battery yields at his will its full content of energy1 either as heat or electricity1 he asks1 ,why may not coal or forest tree1 which are but other kinds of fuel1 be made to do the same8 ,one of the earliest uses of light was a means of communicating intelligence1 and to this day the signal lamp and the red fire of the mariner are as useful as of old4 ,but how much wider is the field of electricity as it creates the telegraph and the telephone6 ,in the telegraph we have all that a pencil of light could be were it as long as an equatorial girdle and as flexible as a silken thread4 ,in the telephone for nearly two thousand miles the pulsations of the speaker's voice are not only audible1 but retain their characteristic tones4 ,in the field of mechanics electricity is decidedly preferable to any other agent4 ,heat may be transformed into motive power by a suitable engine1 but there its adaptability is at an end4 ,an electric current drives not only a motor1 but every machine and tool attached to the motor1 the whole executing tasks of a delicacy and complication new to industrial art4 ,on an electric railroad an identical current propels the train1 directs it by telegraph1 operates its signals1 provides it with light and heat1 while it stands ready to give constant verbal communication with any station on the line1 if this be desired4 ,in the home electricity has equal versatility1 at once promoting healthfulness1 refinement and safety4 ,its tiny button expels the hazardous match as it lights a lamp which sends forth no baleful fumes4 ,an electric fan brings fresh air into the house--in summer as a grateful breeze4 ,simple telephones1 quite effective for their few yards of wire1 give a better because a more flexible service than speaking-tubes4 ,few invalids are too feeble to whisper at the light1 portable ear of metal4 ,sewing-machines and the more exigent apparatus of the kitchen and laundry transfer their demands from flagging human muscles to the tireless sinews of electric motors--which ask no wages when they stand unemployed4 ,similar motors already enjoy favour in working the elevators of tall dwellings in cities4 ,if a householder is timid about burglars1 the electrician offers him a sleepless watchman in the guise of an automatic alarm2 if he has a dread of fire1 let him dispose on his walls an array of thermometers that at the very inception of a blaze will strike a gong at headquarters4 ,but these1 after all1 are matters of minor importance in comparison with the foundations upon which may be reared1 not a new piece of mechanism1 but a new science or a new art4 ,in the recent swift subjugation of the territory open alike to the chemist and the electrician1 where each advances the quicker for the other's company1 we have fresh confirmation of an old truth--that the boundary lines which mark off one field of science from another are purely artificial1 are set up only for temporary convenience4 ,the chemist has only to dig deep enough to find that the physicist and himself occupy common ground4 ,delve from the surface of your sphere to its heart1 and at once your radius joins every other4 ,even the briefest glance at electro-chemistry should pause to acknowledge its profound debt to the new theories as to the bonding of atoms to form molecules1 and of the continuity between solution and electrical dissociation4 ,however much these hypotheses may be modified as more light is shed on the geometry and the journeyings of the molecule1 they have for the time being recommended themselves as finder-thoughts of golden value4 ,these speculations of the chemist carry him back perforce to the days of his childhood4 ,as he then joined together his black and white bricks he found that he could build cubes of widely different patterns4 ,it was in propounding a theory of molecular architecture that ,kekule gave an impetus to a vast and growing branch of chemical industry--that of the synthetic production of dyes and allied compounds4 ,it was in pure research1 in paths undirected to the market-place1 that such theories have been thought out4 ,let us consider electricity as an aid to investigation conducted for its own sake4 ,the chief physical generalization of our time1 and of all time1 the persistence of force1 emerged to view only with the dawn of electric art4 ,when it was observed that electricity might become heat1 light1 chemical action1 or mechanical motion1 that in turn any of these might produce electricity1 it was at once indicated that all these phases of energy might differ from each other only as the movements in circles1 volutes1 and spirals of ordinary mechanism4 ,the suggestion was confirmed when electrical measurers were refined to the utmost precision1 and a single quantum of energy was revealed a very ,proteus in its disguises1 yet beneath these disguises nothing but constancy itself4 ,there is that scattereth1 and yet increaseth2 and there is that withholdeth more than is meet1 but it tendeth to poverty4 ,because the geometers of old patiently explored the properties of the triangle1 the circle1 and the ellipse1 simply for pure love of truth1 they laid the corner-stones for the arts of the architect1 the engineer1 and the navigator4 ,in like manner it was the disinterested work of investigation conducted by ,ampere1 ,faraday1 ,henry and their compeers1 in ascertaining the laws of electricity which made possible the telegraph1 the telephone1 the dynamo1 and the electric furnace4 ,the vital relations between pure research and economic gain have at last worked themselves clear4 ,it is perfectly plain that a man who has it in him to discover laws of matter and energy does incomparably more for his kind than if he carried his talents to the mint for conversion into coin4 ,the voyage of a ,columbus may not immediately bear as much fruit as the uncoverings of a mine prospector1 but in the long run a ,columbus makes possible the finding many mines which without him no prospector would ever see4 ,therefore let the seed-corn of knowledge be planted rather than eaten4 ,but in choosing between one research and another it is impossible to foretell which may prove the richer in its harvests2 for instance1 all attempts thus far economically to oxidize carbon for the production of electricity have failed1 yet in observations that at first seemed equally barren have lain the hints to which we owe the incandescent lamp and the wireless telegraph4 ,perhaps the most promising field of electrical research is that of discharges at high pressures2 here the leading ,american investigators are ,professor ,john ,trowbridge and ,professor ,elihu ,thomson4 ,employing a tension estimated at one and a half millions volts1 ,professor ,trowbridge has produced flashes of lightning six feet in length in atmospheric air2 in a tube exhausted to one-seventh of atmospheric pressure the flashes extended themselves to forty feet4 ,according to this inquirer1 the familiar rending of trees by lightning is due to the intense heat developed in an instant by the electric spark2 the sudden expansion of air or steam in the cavities of the wood causes an explosion4 ,the experiments of ,professor ,thomson confront him with some of the seeming contradictions which ever await the explorer of new scientific territory4 ,in the atmosphere an electrical discharge is facilitated when a metallic terminal 7as a lightning rod7 is shaped as a point2 under oil a point is the form least favourable to discharge4 ,in the same line of paradox it is observed that oil steadily improves in its insulating effect the higher the electrical pressure committed to its keeping2 with air as an insulator the contrary is the fact4 ,these and a goodly array of similar puzzles will1 without doubt1 be cleared up as students in the twentieth century pass from the twilight of anomaly to the sunshine of ascertained law4 ,before there can be applied science there must be science to apply1 and it is by enabling the investigator to know nature under a fresh aspect that electricity rises to its highest office4 ,the laboratory routine of ascertaining the conductivity1 polarisability1 and other electrical properties of matter is dull and exacting work1 but it opens to the student new windows through which to peer at the architecture of matter4 ,that architecture1 as it rises to his view1 discloses one law of structure after another2 what in a first and clouded glance seemed anomaly is now resolved and reconciled2 order displays itself where once anarchy alone appeared4 ,when the investigator now needs a substance of peculiar properties he knows where to find it1 or has a hint for its creation--a creation perhaps new in the history of the world4 ,as he thinks of the wealth of qualities possessed by his store of alloys1 salts1 acids1 alkalies1 new uses for them are borne into his mind4 ,yet more--a new orchestration of inquiry is possible by means of the instruments created for him by the electrician1 through the advances in method which these instruments effect4 ,with a second and more intimate point of view arrives a new trigonometry of the particle1 a trigonometry inconceivable in pre-electric days4 ,hence a surround is in progress which early in the twentieth century may go full circle1 making atom and molecule as obedient to the chemist as brick and stone are to the builder now4 ,the laboratory investigator and the commercial exploiter of his discoveries have been by turns borrower and lender1 to the great profit of both4 ,what ,leyden jar could ever be constructed of the size and revealing power of an ,atlantic cable8 ,and how many refinements of measurement1 of purification of metals1 of precision in manufacture1 have been imposed by the colossal investments in deep-sea telegraphy alone6 ,when a current admitted to an ocean cable1 such as that between ,brest and ,new ,york1 can choose for its path either #c1edj miles of copper wire or a quarter of an inch of gutta-percha1 there is a dangerous opportunity for escape into the sea1 unless the current is of nicely adjusted strength1 and the insulator has been made and laid with the best-informed skill1 the most conscientious care4 ,in the constant tests required in laying the first cables ,lord ,kelvin 7then ,professor ,william ,thomson7 felt the need for better designed and more sensitive galvanometers or current measurers4 ,his great skill both as a mathematician and a mechanician created the existing instruments1 which seem beyond improvement4 ,they serve not only in commerce and manufacture1 but in promoting the strictly scientific work of the laboratory4 ,now that electricity purifies copper as fire cannot1 the mathematician is able to treat his problems of long-distance transmission1 of traction1 of machine design1 with an economy and certainty impossible when his materials were not simply impure1 but impure in varying and indefinite degrees4 ,the factory and the workshop originally took their magneto-machines from the experimental laboratory2 they have returned them remodelled beyond recognition as dynamos and motors of almost ideal effectiveness4 ,a galvanometer actuated by a thermo-electric pile furnishes much the most sensitive means of detecting changes of temperature2 hence electricity enables the physicist to study the phenomena of heat with new ease and precision4 ,it was thus that ,professor ,tyndall conducted the classical researches set forth in his ,heat as a ,mode of ,motion1 ascertaining the singular power to absorb terrestrial heat which makes the aqueous vapours of the atmosphere act as an indispensable blanket to the earth4 ,and how vastly has electricity1 whether in the workshop or laboratory1 enlarged our conceptions of the forces that thrill space1 of the substances1 seemingly so simple1 that surround us--substances that propound questions of structure and behaviour that silence the acutest investigator4 ,you ask me1 said a great physicist1 if ,i have a theory of the universe8 ,why1 ,i haven't even a theory of magnetism6 ,the conventional phrase conducting a current is now understood to be mere figure of speech2 it is thought that a wire does little else than give direction to electric energy4 ,pulsations of high tension have been proved to be mainly superficial in their journeys1 so that they are best conveyed 7or convoyed7 by conductors of tubular form4 ,and what is it that moves when we speak of conduction8 ,it seems to be now the molecule of atomic chemistry1 and anon the same ether that undulates with light or radiant heat4 ,indeed1 the conquest of electricity means so much because it impresses the molecule and the ether into service as its vehicles of communication4 ,instead of the old-time masses of metal1 or bands of leather1 which moved stiffly through ranges comparatively short1 there is to-day employed a medium which may traverse #ahf1djj miles in a second1 and with resistances most trivial in contrast with those of mechanical friction4 ,and what is friction in the last analysis but the production of motion in undesired forms1 the allowing valuable energy to do useless work8 ,in that amazing case of long distance transmission1 common sunshine1 a solar beam arrives at the earth from the sun not one whit the weaker for its excursion of #ib1jjj1jjj miles4 ,it is highly probable that we are surrounded by similar cases of the total absence of friction in the phenomena of both physics and chemistry1 and that art will come nearer and nearer to nature in this immunity is assured when we see how many steps in that direction have already been taken by the electrical engineer4 ,in a preceding page a brief account was given of the theory that gases and vapours are in ceaseless motion4 ,this motion suffers no abatement from friction1 and hence we may infer that the molecules concerned are perfectly elastic4 ,the opinion is gaining ground among physicists that all the properties of matter1 transparency1 chemical combinability1 and the rest1 are due to immanent motion in particular orbits1 with diverse velocities4 ,if this be established1 then these motions also suffer no friction1 and go on without resistance forever4 ,as the investigators in the vanguard of science discuss the constitution of matter1 and weave hypotheses more or less fruitful as to the interplay of its forces1 there is a growing faith that the day is at hand when the tie between electricity and gravitation will be unveiled--when the reason why matter has weight will cease to puzzle the thinker4 ,who can tell what relief of man's estate may be bound up with the ability to transform any phase of energy into any other without the circuitous methods and serious losses of to-day6 ,in the sphere of economic progress one of the supreme advances was due to the invention of money1 the providing a medium for which any salable thing may be exchanged1 with which any purchasable thing may be bought4 ,as soon as a shell1 or a hide1 or a bit of metal was recognized as having universal convertibility1 all the delays and discounts of barter were at an end4 ,in the world of physics and chemistry the corresponding medium is electricity2 let it be produced as readily as it produces other modes of motion1 and human art will take a stride forward such as when ,volta disposed his zinc and silver discs together1 or when ,faraday set a magnet moving around a copper wire4 ,for all that the electric current is not as yet produced as economically as it should be1 we do wrong if we regard it as an infant force4 ,however much new knowledge may do with electricity in the laboratory1 in the factory1 or in the exchange1 some of its best work is already done4 ,it is not likely ever to perform a greater feat than placing all mankind within ear-shot of each other4 ,were electricity unmastered there could be no democratic government of the ,united ,states4 ,to-day the drama of national affairs is more directly in view of every ,american citizen than1 a century ago1 the public business of ,delaware could be to the men of that little ,state4 ,and when on the broader stage of international politics misunderstandings arise1 let us note how the telegraph has modified the hard-and-fast rules of old-time diplomacy4 ,to-day1 through the columns of the press1 the facts in controversy are instantly published throughout the world1 and thus so speedily give rise to authoritative comment that a severe strain is put upon negotiators whose tradition it is to be both secret and slow4 ,railroads1 with all they mean for civilization1 could not have extended themselves without the telegraph to control them4 ,and railroads and telegraphs are the sinews and nerves of national life1 the prime agencies in welding the diverse and widely separated ,states and ,territories of the ,union4 ,a ,boston merchant builds a cotton-mill in ,georgia2 a ,new ,york capitalist opens a copper-mine in ,arizona4 ,the telegraph which informs them day by day how their investments prosper tells idle men where they can find work1 where work can seek idle men4 ,chicago is laid in ashes1 ,charleston topples in earthquake1 ,johnstown is whelmed in flood1 and instantly a continent springs to their relief4 ,and what benefits issue in the strictly commercial uses of the telegraph6 ,at its click both locomotive and steamship speed to the relief of famine in any quarter of the globe4 ,in times of plenty or of dearth the markets of the globe are merged and are brought to every man's door4 ,not less striking is the neighbourhood guild of science1 born1 too1 of the telegraph4 ,the day after ,roentgen announced his ,x rays1 physicists on every continent were repeating his experiments--were applying his discovery to the healing of the wounded and diseased4 ,let an anti-toxin for diphtheria1 consumption1 or yellow fever be proposed1 and a hundred investigators the world over bend their skill to confirm or disprove1 as if the suggester dwelt next door4 ,on a stage less dramatic1 or rather not dramatic at all1 electricity works equal good4 ,its motor freeing us from dependence on the horse is spreading our towns and cities into their adjoining country4 ,field and garden compete with airless streets4 ,the sunny cottage is in active rivalry with the odious tenement-house4 ,it is found that transportation within the gates of a metropolis has an importance second only to the means of transit which links one city with another4 ,the engineer is at last filling the gap which too long existed between the traction of horses and that of steam4 ,in point of speed1 cleanliness1 and comfort such an electric subway as that of ,south ,london leaves nothing to be desired4 ,throughout ,america electric roads1 at first suburban1 are now fast joining town to town and city to city1 while1 as auxiliaries to steam railroads1 they place sparsely settled communities in the arterial current of the world1 and build up a ready market for the dairyman and the fruit-grower4 ,in its saving of what ,mr4 ,oscar ,t4 ,crosby has called man-hours the third-rail system is beginning to oust steam as a motive power from trunk-lines4 ,already shrewd railroad managers are granting partnerships to the electricians who might otherwise encroach upon their dividends4 ,a service at first restricted to passengers has now extended itself to the carriage of letters and parcels1 and begins to reach out for common freight4 ,we may soon see the farmer's cry for good roads satisfied by good electric lines that will take his crops to market much more cheaply and quickly than horses and macadam ever did4 ,in cities1 electromobile cabs and vans steadily increase in numbers1 furthering the quiet and cleanliness introduced by the trolley car4 ,a word has been said about the blessings which electricity promises to country folk1 yet greater are the boons it stands ready to bestow in the hives of population4 ,until a few decades ago the water-supply of cities was a matter not of municipal but of individual enterprise2 water was drawn in large part from wells here and there1 from lines of piping laid in favoured localities1 and always insufficient4 ,many an epidemic of typhoid fever was due to the contamination of a spring by a cesspool a few yards away4 ,to-day a supply such as that of ,new ,york is abundant and cheap because it enters every house4 ,let a centralized electrical service enjoy a like privilege1 and it will offer a current which is heat1 light1 chemical energy1 or motive power1 and all at a wage lower than that of any other servant4 ,unwittingly1 then1 the electrical engineer is a political reformer of high degree1 for he puts a new premium upon ability and justice at the ,city ,hall4 ,his sole condition is that electricity shall be under control at once competent and honest4 ,let us hope that his plea1 joined to others as weighty1 may quicken the spirit of civic righteousness so that some of the richest fruits ever borne in the garden of science and art may not be proffered in vain4 ,flame1 the old-time servant1 is individual2 electricity1 its successor and heir1 is collective4 ,flame sits upon the hearth and draws a family together2 electricity1 welling from a public source1 may bind into a unit all the families of a vast city1 because it makes the benefit of each the interest of all4 ,but not every promise brought forward in the name of the electrician has his assent or sanction4 ,so much has been done by electricity1 and so much more is plainly feasible1 that a reflection of its triumphs has gilded many a baseless dream4 ,one of these is that the cheap electric motor1 by supply power at home1 will break up the factory system1 and bring back the domestic manufacturing of old days4 ,but if this power cost nothing at all the gift would leave the factory unassailed2 for we must remember that power is being steadily reduced in cost from year to year1 so that in many industries it has but a minor place among the expenses of production4 ,the strength and profit of the factory system lie in its assembling a wide variety of machines1 the first delivering its product to the second for another step toward completion1 and so on until a finished article is sent to the ware-room4 ,it is this minute subdivision of labour1 together with the saving and efficiency that inure to a business conducted on an immense scale under a single manager1 that bids us believe that the factory has come to stay4 ,to be sure1 a weaver1 a potter1 or a lens-grinder of peculiar skill may thrive at his loom or wheel at home2 but such a man is far from typical in modern manufacture4 ,besides1 it is very questionable whether the lamentations over the home industries of the past do not ignore evil concomitants such as still linger in the home industries of the present--those of the sweater's den1 for example4 ,this rapid survey of what electricity has done and may yet do--futile expectation dismissed--has shown it the creator of a thousand material resources1 the perfector of that communication of things1 of power1 of thought1 which in every prior stage of advancement has marked the successive lifts of humanity4 ,it was much when the savage loaded a pack upon a horse or an ox instead of upon his own back2 it was yet more when he could make a beacon-flare give news or warning to a whole country-side1 instead of being limited to the messages which might be read in his waving hands4 ,all that the modern engineer was able to do with steam for locomotion is raised to a higher plane by the advent of his new power1 while the long-distance transmission of electrical energy is contracting the dimensions of the planet to a scale upon which its cataracts in the wilderness drive the spindles and looms of the factory town1 or illuminate the thoroughfares of cities4 ,beyond and above all such services as these1 electricity is the corner-stone of physical generalization1 a revealer of truths impenetrable by any other ray4 ,the subjugation of fire has done much in giving man a new independence of nature1 a mighty armoury against evil4 ,in curtailing the most arduous and brutalizing forms of toil1 electricity1 that subtler kind of fire1 carries this emancipation a long step further1 and1 meanwhile1 bestows upon the poor many a luxury which but lately was the exclusive possession of the rich4 ,in more closely binding up the good of the bee with the welfare of the hive1 it is an educator and confirmer of every social bond4 ,in so far as it proffers new help in the war on pain and disease it strengthens the confidence of man in an ,order of ,right and ,happiness which for so many dreary ages has been a matter rather of hope than of vision4 ,are we not1 then1 justified in holding electricity to be a multiplier of faculty and insight1 a means of dignifying mind and soul1 unexampled since man first kindled fire and rejoiced8 ,we have traced how dexterity rose to fire-making1 how fire-making led to the subjugation of electricity4 ,much of the most telling work of fire can be better done by its great successor1 while electricity performs many tasks possible only to itself4 ,unwitting truth there was in the simple fable of the captive who let down a spider's film1 that drew up a thread1 which in turn brought up a rope--and freedom4 ,it was in #ahjj on the threshold of the nineteenth century1 that ,volta devised the first electric battery4 ,in a hundred years the force then liberated has vitally interwoven itself with every art and science1 bearing fruit not to be imagined even by men of the stature of ,watt1 ,lavoisier1 or ,humboldt4 ,compare this rapid march of conquest with the slow adaptation1 through age after age1 of fire to cooking1 smelting1 tempering4 ,yet it was partly1 perhaps mainly1 because the use of fire had drawn out man's intelligence and cultivated his skill that he was ready in the fulness of time so quickly to seize upon electricity and subdue it4 ,electricity is as legitimately the offspring of fire as fire of the simple knack in which one savage in ten thousand was richer than his fellows4 ,the principle of permutation1 suggested in both victories1 interprets not only how vast empire is won by a new weapon of prime dignity2 it explains why such empires are brought under rule with ever-accelerated pace4 ,every talent only pioneers the way for the richer talents which are born from it4 ,,footnotes3 #e ,permutations are the various ways in which two or more different things may be arranged in a row1 all the things appearing in each row4 ,permutations are readily illustrated with squares or cubes of different colours1 with numbers1 or letters4 ,permutations of two elements1 #a and #b1 are 7#a x #b7 two2 #a1 #b2 #b1 #a2 or a1 b2 b1 a4 ,of three elements the permutations are 7#a x #b x #c7 six2 #a1 #b1 #c2 #a1 #c1 #b2 #b1 #a1 #c2 #b1 #c1 #a2 #c1 #a1 #b2 #c1 #b1 #a2 or a1 b1 c2 a1 c1 b2 b1 a1 c2 b1 c1 a2 c1 a1 b2 c1 b1 a4 ,of four elements the permutations are 7#a x #b x #c x #d7 twenty-four2 of five elements1 one hundred and twenty1 and so on4 ,a new element or permutator multiplies by an increasing figure all the permutations it finds4 #f ,some years ago ,i sent an outline of this argument to ,herbert ,spencer1 who replied3 ,i recognize a novelty and value in your inference that the law implies an increasing width of gap between lower and higher types as evolution advances4 ,,count ,,rumford ,,identifies ,,heat ,,with ,,motion4 ,benjamin ,thompson1 who received the title of ,count ,rumford from the ,elector of ,bavaria1 was born in ,woburn1 ,massachusetts1 in #agec4 ,when thirty-one years of age he settled in ,munich1 where he devoted his remarkable abilities to the public service4 ,twelve years afterward he removed to ,england2 in #ahjj he founded the ,royal ,institution of ,london1 since famous as the theatre of the labours of ,davy1 ,faraday1 ,tyndall1 and ,dewar4 ,he bequeathed to ,harvard ,university a fund to endow a professorship of the application of science to the art of living3 he instituted a prize to be awarded by the ,american ,academy of ,sciences for the most important discoveries and improvements relating to heat and light4 ,in #ahjd he married the widow of the illustrious chemist ,lavoisier3 he died in #ahad4 ,count ,rumford on ,january #be1 #agih1 read a paper before the ,royal ,society entitled ,an ,enquiry ,concerning the ,source of ,heat ,which ,is ,excited by ,friction4 ,the experiments therein detailed proved that heat is identical with motion1 as against the notion that heat is matter4 ,he thus laid the corner-stone of the modern theory that heat light1 electricity1 magnetism1 chemical action1 and all other forms of energy are in essence motion1 are convertible into one another1 and as motion are indestructible4 ,the following abstract of ,count ,rumford's paper is taken from ,heat as a ,mode of ,motion1 by ,professor ,john ,tyndall1 published by ,d4 ,appleton ,co41 ,new ,york4 ,this work and ,the ,correlation and ,conservation of ,forces1 edited by ,dr4 ,e4 ,l4 ,youmans1 published by the same house1 will serve as a capital introduction to the modern theory that energy is motion which1 however varied in its forms1 is changeless in its quantity4 ,being engaged in superintending the boring of cannon in the workshops of the military arsenal at ,munich1 ,count ,rumford was struck with the very considerable degree of heat which a brass gun acquires1 in a short time1 in being bored1 and with the still more intense heat 7much greater than that of boiling water7 of the metallic chips separated from it by the borer1 he proposed to himself the following questions3 ,whence comes the heat actually produced in the mechanical operations above mentioned8 ,is it furnished by the metallic chips which are separated from the metal8 ,if this were the case1 then the capacity for heat of the parts of the metal so reduced to chips ought not only to be changed1 but the change undergone by them should be sufficiently great to account for all the heat produced4 ,no such change1 however1 had taken place1 for the chips were found to have the same capacity as slices of the same metal cut by a fine saw1 where heating was avoided4 ,hence1 it is evident1 that the heat produced could not possibly have been furnished at the expense of the latent heat of the metallic chips4 ,rumford describes these experiments at length1 and they are conclusive4 ,he then designed a cylinder for the express purpose of generating heat by friction1 by having a blunt borer forced against its solid bottom1 while the cylinder was turned around its axis by the force of horses4 ,to measure the heat developed1 a small round hole was bored in the cylinder for the purpose of introducing a small mercurial thermometer4 ,the weight of the cylinder was #aac4ac pounds avoirdupois4 ,the borer was a flat piece of hardened steel1 #j4fc of an inch thick1 four inches long1 and nearly as wide as the cavity of the bore of the cylinder1 namely1 three and one-half inches4 ,the area of the surface by which its end was in contact with the bottom of the bore was nearly two and one-half inches4 ,at the beginning of the experiment the temperature of the air in the shade1 and also that of the cylinder1 was #fj deg4 ,fahr4 ,at the end of thirty minutes1 and after the cylinder had made #ifj revolutions round its axis1 the temperature was found to be #acj deg44 ,having taken away the borer1 he now removed the metallic dust1 or rather scaly matter1 which had been detached from the bottom of the cylinder by the blunt steel borer1 and found its weight to be #hcg grains troy4 ,is it possible1 he exclaims1 that the very considerable quantity of heat produced in this experiment--a quantity which actually raised the temperature of above #aac pounds of gun-metal at least #gj deg4 of ,fahrenheit's thermometer--could have been furnished by so inconsiderable a quantity of metallic dust and this merely in consequence of a change in its capacity of heat8 ,but without insisting on the improbability of this supposition1 we have only to recollect that from the results of actual and decisive experiments1 made for the express purpose of ascertaining that fact1 the capacity for heat for the metal of which great guns are cast is not sensibly changed by being reduced to the form of metallic chips1 and there does not seem to be any reason to think that it can be much changed1 if it be changed at all1 in being reduced to much smaller pieces by a borer which is less sharp4 ,he next surrounded his cylinder by an oblong deal-box1 in such a manner that the cylinder could turn water-tight in the centre of the box1 while the borer was pressed against the bottom of the cylinder4 ,the box was filled with water until the entire cylinder was covered1 and then the apparatus was set in action4 ,the temperature of the water on commencing was #fj deg44 ,the result of this beautiful experiment1 writes ,rumford1 was very striking1 and the pleasure it afforded me amply repaid me for all the trouble ,i had had in contriving and arranging the complicated machinery used in making it4 ,the cylinder had been in motion but a short time1 when ,i perceived1 by putting my hand into the water1 and touching the outside of the cylinder1 that heat was generated4 ,at the end of one hour the fluid1 which weighed #ah4gg pounds1 or two and one-half gallons1 had its temperature raised forty-seven degrees1 being now #ajg deg44 ,in thirty minutes more1 or one hour and thirty minutes after the machinery had been set in motion1 the heat of the water was #adb deg44 ,at the end of two hours from the beginning1 the temperature was #agh deg44 ,at two hours and twenty minutes it was #bjj deg41 and at two hours and thirty minutes it actually boiled6 ,it would be difficult to describe the surprise and astonishment expressed in the countenances of the bystanders on seeing so large a quantity of water heated1 and actually made to boil1 without any fire4 ,though1 there was nothing that could be considered very surprising in this matter1 yet ,i acknowledge fairly that it afforded me a degree of childish pleasure which1 were ,i ambitious of the reputation of a grave philosopher1 ,i ought most certainly rather to hide than to discover4 ,he then carefully estimates the quantity of heat possessed by each portion of his apparatus at the conclusion of the experiment1 and1 adding all together1 finds a total sufficient to raise #bf4eh pounds of ice-cold water to its boiling point1 or through #ahj deg4 ,fahrenheit4 ,by careful calculation1 he finds this heat equal to that given out by the combustion of #b1cjc4h grains 7equal to four and eight-tenths ounces troy7 of wax4 ,he then determines the celerity with which the heat was generated1 summing up thus3 ,from the results of these computations1 it appears that the quantity of heat produced equably1 or in a continuous stream1 if ,i may use the expression1 by the friction of the blunt steel borer against the bottom of the hollow metallic cylinder1 was greater than that produced in the combustion of nine wax-candles1 each three-quarters of an inch in diameter1 all burning together with clear bright flames4 ,one horse would have been equal to the work performed1 though two were actually employed4 ,heat may thus be produced merely by the strength of a horse1 and1 in a case of necessity1 this heat might be used in cooking victuals4 ,but no circumstances could be imagined in which this method of procuring heat would be advantageous1 for more heat might be obtained by using the fodder necessary for the support of a horse as fuel4 ,this is an extremely significant passage1 intimating as it does1 that ,rumford saw clearly that the force of animals was derived from the food2 no creation of force taking place in the animal body4 ,by meditating on the results of all these experiments1 we are naturally brought to that great question which has so often been the subject of speculation among philosophers1 namely1 ,what is heat--is there any such thing as an igneous fluid8 ,is there anything that1 with propriety1 can be called caloric8 ,we have seen that a very considerable quantity of heat may be excited by the friction of two metallic surfaces1 and given off in a constant stream or flux in all directions1 without interruption or intermission1 and without any signs of diminution or exhaustion4 ,in reasoning on this subject we must not forget that most remarkable circumstance1 that the source of the heat generated by friction in these experiments appeared evidently to be inexhaustible4 ,the italics are ,rumford's4 ,it is hardly necessary to add1 that anything which any insulated body or system of bodies can continue to furnish without limitation cannot possibly be a material substance2 and it appears to me to be extremely difficult1 if not quite impossible1 to form any distinct idea of anything capable of being excited and communicated in those experiments1 except it be ,,motion4 ,when the history of the dynamical theory of heat is written1 the man who1 in opposition to the scientific belief of his time1 could experiment and reason upon experiment1 as ,rumford did in the investigation here referred to1 cannot be lightly passed over4 ,hardly anything more powerful against the materiality of heat has been since adduced1 hardly anything more conclusive in the way of establishing that heat is1 what ,rumford considered it to be1 ,motion4 ,,victory ,,of ,,the ,,rocket ,,locomotive4 ,part of ,chapter ,,xii4 ,part ,,ii1 of ,the ,life of ,george ,stephenson and of ,his ,son1 ,robert ,stephenson1 by ,samuel ,smiles ,new ,york1 ,harper ,brothers1 #ahfh4 ,the works of the ,liverpool and ,manchester ,railway were now approaching completion4 ,but1 strange to say1 the directors had not yet decided as to the tractive power to be employed in working the line when open for traffic4 ,the differences of opinion among them were so great as apparently to be irreconcilable4 ,it was necessary1 however1 that they should1 come to some decision without further loss of time1 and many board meetings were accordingly held to discuss the subject4 ,the old-fashioned and well-tried system of horse-haulage was not without its advocates2 but1 looking at the large amount of traffic which there was to be conveyed1 and at the probable delay in the transit from station to station if this method were adopted1 the directors1 after a visit made by them to the ,northumberland and ,durham railways in #ahbh1 came to the conclusion that the employment of horse-power was inadmissible4 ,fixed engines had many advocates2 the locomotive very few3 it stood as yet almost in a minority of one--,george ,stephenson4444 ,in the meantime the discussion proceeded as to the kind of power to be permanently employed for the working of the railway4 ,the directors were inundated with schemes of all sorts for facilitating locomotion4 ,the projectors of ,england1 ,france1 and ,america seemed to be let loose upon them4 ,there were plans for working the waggons along the line by water-power4 ,some proposed hydrogen1 and others carbonic acid gas4 ,atmospheric pressure had its eager advocates4 ,and various kinds of fixed and locomotive steam-power were suggested4 ,thomas ,gray urged his plan of a greased road with cog-rails2 and ,messrs4 ,vignolles and ,ericsson recommended the adoption of a central friction-rail1 against which two horizontal rollers under the locomotive1 pressing upon the sides of this rail1 were to afford the means of ascending the inclined planes4444 ,the two best practical engineers of the day concurred in reporting substantially in favour of the employment of fixed engines4 ,not a single professional man of eminence could be found to coincide with the engineer of the railway in his preference for locomotive over fixed engine power4 ,he had scarcely a supporter1 and the locomotive system seemed on the eve of being abandoned4 ,still he did not despair4 ,with the profession against him1 and public opinion against him--for the most frightful stories went abroad respecting the dangers1 the unsightliness1 and the nuisance which the locomotive would create--,stephenson held to his purpose4 ,even in this1 apparently the darkest hour of the locomotive1 he did not hesitate to declare that locomotive railroads would1 before many years had passed1 be the great highways of the world4 ,he urged his views upon the directors in all ways1 in season1 and1 as some of them thought1 out of season4 ,he pointed out the greater convenience of locomotive power for the purposes of a public highway1 likening it to a series of short unconnected chains1 any one of which could be removed and another substituted without interruption to the traffic2 whereas the fixed-engine system might be regarded in the light of a continuous chain extending between the two termini1 the failure of any link of which would derange the whole4 ,but the fixed engine party was very strong at the board1 and1 led by ,mr4 ,cropper1 they urged the propriety of forthwith adopting the report of ,messrs4 ,walker and ,rastrick4 ,mr4 ,sandars and ,mr4 ,william ,rathbone1 on the other hand1 desired that a fair trial should be given to the locomotive2 and they with reason objected to the expenditure of the large capital necessary to construct the proposed engine-houses1 with their fixed engines1 ropes1 and machinery1 until they had tested the powers of the locomotive as recommended by their own engineer4 ,george ,stephenson continued to urge upon them that the locomotive was yet capable of great improvements1 if proper inducements were held out to inventors and machinists to make them2 and he pledged himself that1 if time were given him1 he would construct an engine that should satisfy their requirements1 and prove itself capable of working heavy loads along the railway with speed1 regularity1 and safety4 ,at length1 influenced by his persistent earnestness not less than by his arguments1 the directors1 at the suggestion of ,mr4 ,harrison1 determined to offer a prize of ,l#ejj for the best locomotive engine1 which1 on a certain day1 should be produced on the railway1 and perform certain specified conditions in the most satisfactory manner4#g ,the requirements of the directors as to speed were not excessive4 ,all that they asked for was that ten miles an hour should be maintained4 ,perhaps they had in mind the animadversions of the ,quarterly ,review on the absurdity of travelling at a greater velocity1 and also the remarks published by ,mr4 ,nicholas ,wood1 whom they selected to be one of the judges of the competition1 in conjunction1 with ,mr4 ,rastrick1 of ,stourbridge1 and ,mr4 ,kennedy1 of ,manchester4 ,it was now felt that the fate of railways in a great measure depended upon the issue of this appeal to the mechanical genius of ,england4 ,when the advertisement of the prize for the best locomotive was published1 scientific men began more particularly to direct their attention to the new power which was thus struggling into existence4 ,in the meantime public opinion on the subject of railway working remained suspended1 and the progress of the undertaking was watched with intense interest4 ,during the progress of this important controversy with reference to the kind of power to be employed in working the railway1 ,george ,stephenson was in constant communication with his son ,robert1 who made frequent visits to ,liverpool for the purpose of assisting his father in the preparation of his reports to the board on the subject4 ,mr4 ,swanwick remembers the vivid interest of the evening discussions which then took place between father and son as to the best mode of increasing the powers and perfecting the mechanism of the locomotive4 ,he wondered at their quick perception and rapid judgment on each other's suggestions2 at the mechanical difficulties which they anticipated and provided for in the practical arrangement of the machine2 and he speaks of these evenings as most interesting displays of two actively ingenious and able minds stimulating each other to feats of mechanical invention1 by which it was ordained that the locomotive engine should become what it now is4 ,these discussions became more frequent1 and still more interesting1 after the public prize had been offered for the best locomotive by the directors of the railway1 and the working plans of the engine which they proposed to construct had to be settled4 ,one of the most important considerations in the new engine was the arrangement of the boiler1 and the extension of its heating surface to enable steam enough to be raised rapidly and continuously for the purpose of maintaining high rates of speed--the effect of high pressure engines being ascertained to depend mainly upon the quantity of steam which the boiler can generate1 and upon its degree of elasticity when produced4 ,the quantity of steam so generated1 it will be obvious1 must chiefly depend upon the quantity of fuel consumed in the furnace1 and1 by necessary consequence1 upon the high rate of temperature maintained there4 ,it will be remembered that in ,stephenson's first ,killingworth engines he invited and applied the ingenious method of stimulating combustion in the furnace by throwing the waste steam into the chimney after performing its office in the cylinders1 thereby accelerating the ascent of the current of air1 greatly increasing the draught1 and consequently the temperature of the fire4 ,this plan was adopted by him1 as we have seen1 as early as #ahae1 and it was so successful that he himself attributed to it the greater economy of the locomotive as compared with horse-power4 ,hence the continuance of its use upon the ,killingworth ,railway4 ,though the adoption of the steam blast greatly quickened combustion and contributed to the rapid production of high-pressure steam1 the limited amount of heating surface presented to the fire was still felt to be an obstacle to the complete success of the locomotive engine4 ,mr4 ,stephenson endeavoured to overcome this by lengthening the boilers and increasing the surface presented by the flue-tubes4 ,the ,lancashire ,witch1 which he built for the ,bolton and ,leigh ,railway1 and used in forming the ,liverpool and ,manchester ,railway embankments1 was constructed with a double tube1 each of which contained a fire1 and passed longitudinally through the boiler4 ,but this arrangement necessarily led to a considerable increase in the weight of those engines1 which amounted to about twelve tons each2 and as six tons was the limit allowed for engines admitted to the ,liverpool competition1 it was clear that the time was come when the ,killingworth engine must undergo a farther important modification4 ,for many years previous to this period1 ingenious mechanics had been engaged in attempting to solve the problem of the best and most economical boiler for the production of high-pressure steam4 ,the use of tubes in boilers for increasing the heating surface had long been known4 ,as early as #aghj1 ,matthew ,boulton employed copper tubes longitudinally in the boiler of the ,wheal ,busy engine in ,cornwall--the fire passing through the tubes--and it was found that the production of steam was thereby considerably increased4 ,the use of tubular boilers afterwards became common in ,cornwall4 ,in #ahjc1 ,woolf1 the ,cornish engineer1 patented a boiler with tubes1 with the same object of increasing the heating surface4 ,the water was inside the tubes1 and the fire of the boiler outside4 ,similar expedients were proposed by other inventors4 ,in #ahae ,trevithick invented his light high-pressure boiler for portable purposes1 in which1 to expose a large surface to the fire1 he constructed the boiler of a number of small perpendicular tubes opening into a common reservoir at the top4 ,in #ahbc ,w4 ,h4 ,james contrived a boiler composed of a series of annular wrought-iron tubes1 placed side by side and bolted together1 so as to form by their union a long cylindrical boiler1 in the centre of which1 at the end1 the fireplace was situated4 ,the fire played round the tubes1 which contained the water4 ,in #ahbf ,james ,neville took out a patent for a boiler with vertical tubes surrounded by the water1 through which the heated air of the furnace passed1 explaining also in his specification that the tubes might be horizontal or inclined1 according to circumstances4 ,mr4 ,goldsworthy1 the persevering adaptor of steam-carriages to travelling on common roads1 applied the tubular principle in the boiler of his engine1 in which the steam was generated within the tubes2 while the boiler invented by ,messrs4 ,summer and ,ogle for their turnpike-road steam-carriage consisted of a series of tubes placed vertically over the furnace1 through which the heated air passed before reaching the chimney4 ,about the same time ,george ,stephenson was trying the effect of introducing small tubes in the boilers of his locomotives1 with the object of increasing their evaporative power4 ,thus1 in #ahbi1 he sent to ,france two engines constructed at the ,newcastle works for the ,lyons and ,st4 ,etienne ,railway1 in the boilers of which tubes were placed containing water4 ,the heating surface was thus considerably increased2 but the expedient was not successful1 for the tubes1 becoming furred with deposit1 shortly burned out and were removed4 ,it was then that ,m4 ,seguin1 the engineer of the railway1 pursuing the same idea1 is said to have adopted his plan of employing horizontal tubes through which the heated air passed in streamlets1 and for which he took out a ,french patent4 ,in the meantime ,mr4 ,henry ,booth1 secretary to the ,liverpool and ,manchester ,railway1 whose attention had been directed to the subject on the prize being offered for the best locomotive to work that line1 proposed the same method1 which1 unknown to him1 ,matthew ,boulton had employed but not patented1 in #aghj1 and ,james ,neville had patented1 but not employed1 in #ahbf2 and it was carried into effect by ,robert ,stephenson in the construction of the ,rocket1 which won the prize at ,rainhill in ,october1 #ahbi4 ,the following is ,mr4 ,booth's account in a letter to the author3 ,i was in almost daily communication with ,mr4 ,stephenson at the time1 and ,i was not aware that he had any intention of competing for the prize till ,i communicated to him my scheme of a multitubular boiler4 ,this new plan of boiler comprised the introduction of numerous small tubes1 two or three inches in diameter1 and less than one-eighth of an inch thick1 through which to carry the fire instead of a single tube or flue eighteen inches in diameter1 and about half an inch thick1 by which plan we not only obtain a very much larger heating surface1 but the heating surface is much more effective1 as there intervenes between the fire and the water only a thin sheet of copper or brass1 not an eighth of an inch thick1 instead of a plate of iron of four times the substance1 as well as an inferior conductor of heat4 ,when the conditions of trial were published1 ,i communicated my multitubular plan to ,mr4 ,stephenson1 and proposed to him that we should jointly construct an engine and compete for the prize4 ,mr4 ,stephenson approved the plan1 and agreed to my proposal4 ,he settled the mode in which the fire-box and tubes were to be mutually arranged and connected1 and the engine was constructed at the works of ,messrs4 ,robert ,stephenson ,co41 ,newcastle-on-,tyne4 ,i am ignorant of ,m4 ,seguin's proceedings in ,france1 but ,i claim to be the inventor in ,england1 and feel warranted in stating1 without reservation1 that until ,i named my plan to ,mr4 ,stephenson1 with a view to compete for the prize at ,rainhill1 it had not been tried1 and was not known in this country4 ,from the well-known high character of ,mr4 ,booth1 we believe his statement to be made in perfect good faith1 and that he was as much in ignorance of the plan patented by ,neville as he was of that of ,seguin4 ,as we have seen1 from the many plans of tubular boilers invented during the preceding thirty years1 the idea was not by any means new2 and we believe ,mr4 ,booth to be entitled to the merit of inventing the method by which the multitubular principle was so effectually applied in the construction of the famous ,rocket engine4 ,the principal circumstances connected with the construction of the ,rocket1 as described by ,robert ,stephenson to the author1 may be briefly stated4 ,the tubular principle was adopted in a more complete manner than had yet been attempted4 ,twenty-five copper tubes1 each three inches in diameter1 extended from one end of the boiler to the other1 the heated air passing through them on its way to the chimney2 and the tubes being surrounded by the water of the boiler1 it will be obvious that a large extension of the heating surface was thus effectually secured4 ,the principal difficulty was in fitting the copper tubes in the boiler ends so as to prevent leakage4 ,they were manufactured by a ,newcastle coppersmith1 and soldered to brass screws which were screwed into the boiler ends1 standing out in great knobs4 ,when the tubes were thus fitted1 and the boiler was filled with water1 hydraulic pressure was applied2 but the water squirted out at every joint1 and the factory floor was soon flooded4 ,robert went home in despair2 and in the first moment of grief he wrote to his father that the whole thing was a failure4 ,by return of post came a letter from his father1 telling him that despair was not to be thought of--that he must try again2 and he suggested a mode of overcoming the difficulty1 which his son had already anticipated and proceeded to adopt4 ,it was1 to bore clean holes in the boiler ends1 fit in the smooth copper tubes as tightly as possible1 solder up1 and then raise the steam4 ,this plan succeeded perfectly1 the expansion of the copper tubes completely filling up all interstices1 and producing a perfectly water-tight boiler1 capable of withstanding extreme external pressure4 ,the mode of employing the steam-blast for the purpose of increasing the draught in the chimney was also the subject of numerous experiments4 ,when the engine was first tried1 it was thought that the blast in the chimney was not sufficiently strong for the purpose of keeping up the intensity of fire in the furnace1 so as to produce high-pressure steam with the required velocity4 ,the expedient was therefore adopted of hammering the copper tubes at the point at which they entered the chimney1 whereby the blast was considerably sharpened2 and on a farther trial it was found that the draught was increased to such an extent as to enable abundance of steam to be raised4 ,the rationale of the blast may be simply explained by referring to the effect of contracting the pipe of a water-hose1 by which the force of the jet of water is proportionately increased4 ,widen the nozzle of the pipe1 and the jet is in like manner diminished4 ,so it is with the steam-blast in the chimney of the locomotive4 ,doubts were1 however1 expressed whether the greater draught obtained by the contraction of the blast-pipe was not counterbalanced in some degree by the negative pressure upon the piston4 ,hence a series of experiments was made with pipes of different diameters1 and their efficiency was tested by the amount of vacuum that was produced in the smoke-box4 ,the degree of rarefaction was determined by a glass tube fixed to the bottom of the smoke-box and descending into a bucket of water1 the tube being open at both ends4 ,as the rarefaction took place1 the water would1 of course1 rise in the tube1 and the height to which it rose above the surface of the water in the bucket was made the measure of the amount of rarefaction4 ,these experiments proved that a considerable increase of draught was obtained by the contraction of the orifice2 accordingly1 the two blast-pipes opening from the cylinders into either side of the ,rocket chimney1 and turned up within it1 were contracted slightly below the area of the steam-ports1 and before the engine left the factory1 the water rose in the glass tube three inches above the water in the bucket4 ,the other arrangements of the ,rocket were briefly these3 the boiler was cylindrical1 with flat ends1 six feet in length1 and three feet four inches in diameter4 ,the upper half of the boiler was used as a reservoir for the steam1 the lower half being filled with water4 ,through the lower part the copper tubes extended1 being open to the fire-box at one end1 and to the chimney at the other4 ,the fire-box1 or furnace1 two feet wide and three feet high1 was attached immediately behind the boiler1 and was also surrounded with water4 ,the cylinders of the engine were placed on each side of the boiler1 in an oblique position1 one end being nearly level with the top of the boiler at its after end1 and the other pointing toward the centre of the foremost or driving pair of wheels1 with which the connection was directly made from the piston-rod to a pin on the outside of the wheel4 ,the engine1 together with its load of water1 weighed only four tons and a quarter2 and it was supported on four wheels1 not coupled4 ,the tender was four-wheeled1 and similar in shape to a waggon--the foremost part holding the fuel1 and the hind part a water cask4 ,when the ,rocket was finished it was placed upon the ,killingworth ,railway for the purpose of experiment4 ,the new boiler arrangement was found perfectly successful4 ,the steam was raised rapidly and continuously1 and in a quantity which then appeared marvellous4 ,the same evening ,robert despatched a letter to his father at ,liverpool1 informing him1 to his great joy1 that the ,rocket was all right1 and would be in complete working trim by the day of trial4 ,the engine was shortly after sent by waggon to ,carlisle1 and thence shipped for ,liverpool4 ,the time so much longed for by ,george ,stephenson had now arrived1 when the merits of the passenger locomotive were about to be put to the test4 ,he had fought the battle for it until now almost single-handed4 ,engrossed by his daily labours and anxieties1 and harassed by difficulties and discouragements which would have crushed the spirit of a less resolute man1 he had held firmly to his purpose through good and through evil report4 ,the hostility which he experienced from some of the directors opposed to the adoption of the locomotive was the circumstance that caused him the greatest grief of all2 for where he had looked for encouragement1 he found only carping and opposition4 ,but his pluck never failed him2 and now the ,rocket was upon the ground to prove1 to use his own words1 whether he was a man of his word or not4 ,on the day appointed for the great competition of locomotives at ,rainhill the following engines were entered for the prize3 #a4 ,messrs4 ,braithwaite and ,ericsson's ,novelty4 #b4 ,mr4 ,timothy ,hackworth's ,sanspareil4 #c4 ,messrs4 ,r4 ,stephenson ,co4's ,rocket4 #d4 ,mr4 ,burstall's ,perseverance4 ,the ground on which the engines were to be tried was a level piece of railroad1 about two miles in length4 ,each was required to make twenty trips1 or equal to a journey of seventy miles1 in the course of the day1 and the average rate of travelling was to be not under ten miles an hour4 ,it was determined that1 to avoid confusion1 each engine should be tried separately1 and on different days4 ,the day fixed for the competition was the #ast of ,october1 but1 to allow sufficient time to get the locomotives into good working order1 the directors extended it to the #fth4 ,it was quite characteristic of the ,stephensons that1 although their engine did not stand first on the list for trial1 it was the first that was ready1 and it was accordingly ordered out by the judges for an experimental trip4 ,yet the ,rocket was by no means the favourite with either the judges or the spectators4 ,nicholas ,wood has since stated that the majority of the judges were strongly predisposed in favour of the ,novelty1 and that nine-tenths1 if not ten-tenths1 of the persons present were against the ,rocket because of its appearance4 ,nearly every person favoured some other engine1 so that there was nothing for the ,rocket but the practical test4 ,the first trip made by it was quite successful4 ,it ran about twelve miles1 without interruption1 in about fifty-three minutes4 ,the ,novelty was next called out4 ,it was a light engine1 very compact in appearance1 carrying the water and fuel upon the same wheels as the engine4 ,the weight of the whole was only three tons and one hundred-weight4 ,a peculiarity of this engine was that the air was driven or forced through the fire by means of bellows4 ,the day being now far advanced1 and some dispute having arisen as to the method of assigning the proper load for the ,novelty1 no particular experiment was made further than that the engine traversed the line by way of exhibition1 occasionally moving at the rate of twenty-four miles an hour4 ,the ,sanspareil1 constructed by ,mr4 ,timothy ,hackworth1 was next exhibited1 but no particular experiment was made with it on this day4 ,this engine differed but little in its construction from the locomotive last supplied by the ,stephensons to the ,stockton and ,darlington ,railway1 of which ,mr4 ,hackworth was the locomotive foreman4 ,the contest was postponed until the following day2 but1 before the judges arrived on the ground1 the bellows for creating the blast in the ,novelty gave way1 and it was found incapable of going through its performance4 ,a defect was also detected in the boiler of the ,sanspareil1 and some further time was allowed to get it repaired4 ,the large number of spectators who had assembled to witness the contest were greatly disappointed at this postponement2 but1 to lessen it1 ,stephenson again brought out the ,rocket1 and1 attaching it to a coach containing thirty persons1 he ran them along the line at a rate of from twenty-four to thirty miles an hour1 much to their gratification and amazement4 ,before separating1 the judges ordered the engine to be in readiness by eight o'clock on the following morning1 to go through its definite trial according to the prescribed conditions4 ,on the morning of the #hth of ,october the ,rocket was again ready for the contest4 ,the engine was taken to the extremity of the stage1 the fire-box was filled with coke1 the fire lighted1 and the steam raised until it lifted the safety-valve loaded to a pressure of fifty pounds to the square inch4 ,this proceeding occupied fifty-seven minutes4 ,the engine then started on its journey1 dragging after it about thirteen tons' weight in waggons1 and made the first ten trips backward and forward along two miles of road1 running the thirty-five miles1 including stoppages1 in an hour and forty-eight minutes4 ,the second ten trips were in like manner performed in two hours and three minutes4 ,the maximum velocity attained during the trial trip was twenty-nine miles an hour1 or about three times the speed that one of the judges of the competition had declared to be the limit of possibility4 ,the average speed at which the whole of the journeys was performed was fifteen miles an hour1 or five miles beyond the rate specified in the conditions published by the company4 ,the entire performance excited the greatest astonishment among the assembled spectators2 the directors felt confident that their enterprise was now on the eve of success2 and ,george ,stephenson rejoiced to think that1 in spite of all false prophets and fickle counsellors1 the locomotive system was now safe4 ,when the ,rocket1 having performed all the conditions of the contest1 arrived at the grand stand at the close of its day's successful run1 ,mr4 ,cropper--one of the directors favourable to the fixed engine system--lifted up his hands1 and exclaimed1 ,now has ,george ,stephenson at last delivered himself4444 ,the ,rocket had eclipsed the performance of all locomotive engines that had yet been constructed1 and outstripped even the sanguine expectations of its constructors4 ,it satisfactorily answered the report of ,messrs4 ,walker and ,rastrick1 and established the efficiency of the locomotive for working the ,liverpool and ,manchester ,railway1 and1 indeed1 all future railways4 ,the ,rocket showed that a new power had been born into the world1 full of activity and strength1 with boundless capability of work4 ,it was the simple but admirable contrivance of the steam-blast1 and its combination with the multitubular boiler1 that at once gave locomotion a vigorous life1 and secured the triumph of the railway system4#h ,illustration3 ,the ,rocket ,,footnotes3 #g ,the conditions were these3 #a4 ,the engine must effectually consume its own smoke4 #b4 ,the engine1 if of six tons' weight1 must be able to draw after it1 day by day1 twenty tons' weight 7including the tender and water-tank7 at ten miles an hour1 with a pressure of steam on the boiler not exceeding fifty pounds to the square inch4 #c4 ,the boiler must have two safety-valves1 neither of which must be fastened down1 and one of them be completely out of the control of the engine-man4 #d4 ,the engine and boiler must be supported on springs1 and rest on six wheels1 the height of the whole not exceeding fifteen feet to the top of the chimney4 #e4 ,the engine1 with water1 must not weigh more than six tons2 but an engine of less weight would be preferred on its drawing a proportionate load behind it2 if of only four and a half tons1 then it might be put on only four wheels4 ,the company will be at liberty to test the boiler1 etc41 by a pressure of one hundred and fifty pounds to the square inch4 #f4 ,a mercurial gauge must be affixed to the machine1 showing the steam pressure above forty-five pounds per square inch4 #g4 ,the engine must be delivered1 complete and ready for trial1 at the ,liverpool end of the railway1 not later than the #ast of ,october1 #ahbi4 #h4 ,the price of the engine must not exceed ,l#eej4 ,many persons of influence declared the conditions published by the directors of the railway chimerical in the extreme4 ,one gentleman of some eminence in ,liverpool1 ,mr4 ,p4 ,ewart1 who afterward filled the office of ,government ,inspector of ,post-office ,steam ,packets1 declared that only a parcel of charlatans would ever have issued such a set of conditions2 that it had been proved to be impossible to make a locomotive engine go at ten miles an hour2 but if it ever was done1 he would undertake to eat a stewed engine-wheel for his breakfast4 #h ,when heavier and more powerful engines were brought upon the road1 the old ,rocket1 becoming regarded as a thing of no value1 was sold in #ahcg4 ,it has since been transferred to the ,museum of ,patents at ,south ,kensington1 ,london1 where it is still to be seen4 ,transcriber's ,notes3 ,page #cj--;imployed changed to employed4 ,page #ca--subsequenty changed to subsequently4 ,page #dg--;build changed to building4 ,page #adg--suggestor changed to suggester4 ,page #aff--supgestion changed to suggestion4 ,footnote #g--;,changed question mark for a period4 ,inconsistencies in hyphenated words have been made consistent4 ,obvious printer errors1 including punctuation1 have been corrected without note4