The Telephone. Thattheconversion of thequality of speechintomotionsof electridty and that the reproduction of the effect in audible a each is no myth, has recently been proved by what Sir lWilliam Thomson rightly cals " one of the most interesting of the scientific inventions made in this century, or that has ever been made in the history of science." There were telephones before that of Mlr. Alex- ander Graham Bell, but those telephones differed from Mir. Bell's in the same sense as a series of claps of the hand differs from the human voice. They were instruments in which, by electric action, a succession of shocks was produced by suddenly stopping and starting the electric corrents. Mr Bell conceived the original idea of giving continuity to the shocks, and of producing claps which would be in simple proportion to the motion of the air created by the voice, and of reproducing that effect at the remote end of the telegraph wire, be that end far or near, with a motion so nearly sirilar to the motion of the air caused by the voice as that not only is ,the articula- tion of the voice heard, but the different qualities of different voices are distinguished. John Smith in London converses with Thomas Jones in Liverpool as easily as though the distance between them could ,be measured by a few y3ards of spealing tube. No more time is required in the one instance than in the other. The fal of an apple inspired the theory of gravitation; the twitching of a frog's leg led to the electric telegraph, and from equally small beginnings comes Mr. Bell s Tele- phone. While carrying on experiments in regard to the relation of electricity and magnetism, Professor Charles Page, of Salem, Massachusetts, investigated the produc- tion of sound by electric current, and, in 1837, pub- lished the result of his researches in an article en. titled " Galvanic Music," which attracted so much attention in America and Europe that numerous investi- gators went to work to discover the cause of many curious electric sounds. Mr. Bell's own researches in electrical telephony began with the artificial production of musical sounds,he beingat the time engaged inBoston,United States, in the work of teaching the deaf and dumb to speak. Deaf mutes are dumb merely because they are deaf. T'here is no vocal defect to prevent utterance, and Mr. Bell has practically demonstrated by 2,000 of his own papils that when the deaf and dumb Imow how to control the action of their vocal organs they can articulate with comparative facility. Striving to perfect hiis ingenious system of teach- ing, it occurred to Mr. Bell that if, istead of presenting to the eye of the deal mute a system of symbols, he could make visible the vibrations of the air, the appa- ratus might be used as a means of teaching articula- tion. Experimenting with different instruments Mr. Bell found great assistance from the phonautograph, which had justbeen greatly unproved by Mr.Maurey, a student of the Boston Institute of Technology. He had succeeded in vibrating by the voice a stylus of wood, about a foot in length, which vwas attached to the membrane of the phonautograph; and with tlis he obtained enlarged tracings of the vibrations of the, air, pro- duced by the vowel sounds upon a plane surface of smokedglass. M1r.Bell traced a imilarity between the manner iu which this piece of,wood was vibrated by the membrane of the phonautograph, and the manner in which the ossiculse of the human ear were moved by the tympa. nun membrane. This discovery led him to construct a phonautograph modelled losely upon the mechanism of the human ear, calling to his aid Dr. Clarence J. Blake, a distingished aurist of Boston, who suggested the use of the human ear itself and prepared a specimen for this pur- pose. The stapes were removed, and, being lighter, a stylus of hay, about an inch in length, was attached to the end of the incus. Upon moistening the membrana-tympani and the auricoles with a mixture of glycerine and water, the necessary mobility of the parts was obtained, and upon singing into the extenal ar tificial ear, the stylus of hay was throwrn into vibration, and tracings were obtained upon a plane surface of smoked glass passed rapidly mdermeath. While engaged in these experiments, Mr. Bell's attention was arrested by observing the wonderful disproportion which existed between the weight of the membrane and that of the bones vibhted by it. "If a membrane as thinastissue paper," argued Mfr. Bell, "can control thevibration of bones which, oompared to it, are of immense weight and size,why may not a larger and thicker membrane vibrate a piece of iron in front of an electro-magnet.? If this be so, the com- plication of steel rods, suggested by the harp arrangement. can be done away with, and a simple piece of iron.attached to a membrane take their place." Action followed thought. Employing apparats by whic ho he%d been pro- ducing undulatory currents of clectricity for the pur- pose of multiple telegraphy, Mr. Bell attached a rod loosely by one extremity to the uncbvered pole of a magnet and fastened the other extremity to the centre of a strctched membrane of goldbeater skin. }e supposed that [upon speaking in the neighbourhood of the membrane it would be thrown into vibration and cause the stee rod tomovein a similar manner, thereby occasioning undulations in the electrical current that would correspond to the variations in the density of the sir during the pro- duction of sound; and further, that the chnnge in the intensity of the current at the receiving end would cause the magnet there to attract its rod so as to copy the motion imparted to that at the sending end. Mr. Thomas A.u Watson, Mr. Bell's assistant, declsred, during the; experiment, that he heard a faint sound proceea. from the instrument at whiclr he listenedv butb Mr. Bell was less fortunate. Perseveirlng in hl re i searches, Mr. Bell at lut determined to reducethe ize uRn weight of the spring attached to the disphragm as much s possible, and thereupon glued a piece ef clocl;-.spring, abo4t the size and shape of his thumb-nail, to the centre of the diaphragm. This produced audible results, and o the model thus obtained, Mr. Bell constructed his telephone, which consisted of a permanent magnet with a coil of wire round it and an iron plate in front. The vibration of the voloi causvd the vibration of the iron -plate. Tat vibration produced a current of electricity; the current of elec- tricity caused a variation of power iu the magnet in the distant instrument; the variation of power in +he distant magnet caused the iron plate in front of the xagnet t vibrate, andthat vibration produced a sound. he volc was converted into electridty at one end- ma.electrl'ty~ became voice at tha other end. Suck was the instrmeut that Mr. TelpbIt to the Cen.e tenmial Exhibition at Philadelphia, where it attracted the attention of electricans and inspired the following offlciil reporb, signed by Sir William Thomson and others.- "Mr. Alexander Graham Bell exhibitp apparatus by which he has achieved a result of transcendent scicntifhz interest-the transmission of spoken wvords by electrio cur- rents through a telegraph wire. To obtain this result Mr. Bell perceived that he must produce averiationof strength of current in the telegraph wire as nearly as may be in exact proportion to the velocity of a particle of air inoved4 by the sound, and he invented a method of doing so-apiece of iron attached to a membrane, and thus mnpved to and fFr intheneighbourhoodofanelectro-magnet--vhichhs sproved perfectly successful, The battery and wire of this electro- magnet are in circuit with the relegra,ch wire and the wire ef another electro-magnet at the receiving station. This second electro-magnet has a solid bar of iron for core, which is connected at one end by a thick disc of iron to an iron tube surrounding the coil and bar. The free circular end of the tube constitutes one pole of the electro-magnet, and the adjacent free end of the bar core the other. A thin circular iron disc, held pressed against the end of the tube by the electrio magnetio attraction and free to vibrate through a verysmall space without touching the central pole, constitutes the sounder by which the electric etfect is reconverted into wound. WVith my ear pressed against this disc I heard it speak distinctly several sentences. 1 need scarcely say I was astonished and delighted; so were others, including some judges of our group who wit-' nessed the experiments andveriiied with their own can the electric transnission of speech. Thia,perhaps the greatest marvel hitherto achieved by the electrio telegraph,has been obtained by appliances of quite a homespun and rudimen- tary character. With somewhat more advanced plans and more powerful apparatus, we may confidently expect that MIr. Bell wll give us the means of maldng voice and spoken words audible through the electric wire to an ear hundreds. of mfles distant." Inspired by so enthuiastic a verdict, mr. Bell re-: turned to his experiments with renewed energy, aud on the 4th of lay, 1877, theze were strange scenes in the Bolton Music-hall. Going to the small telephone box with itb slender wire attachments, Mr. Bell coolly asked, as though addressing some one in an adjoining room, "Mr.: Wabon, are you ready 2" mr. Watson, five miles a6way in Somerville, promptly answeread in the affirmative, and soon was heard a voice singing " America." Then followed the Portuguese Iymn, to tbh amazement of a hushed audience. Going to another istruent connected by nire with Px6vidence, 43 mniles distant, Mr. Bell listened a mo- menat, ad said, " Signor Brignoli, who is assisting at a concert in the Providence Music-hall, will now sing for us." In a moment tbe cadence of the tenor's notes rose and fel, the sound being faint, sometimes lost, anud then again audible. Later, a cornet solo, played in Somer- ville,wSverydistinctlyheard. Still later, a three-parb songUfloated over the wire from the Somerville terminus, and r. .Bell amused his audience exceedingly by ex- claimng, " I wll switch off the song from one part of tlhe hall to another, so that all canhear." Shuntiggmusic comimg over a wire 43 miles lonag, s thongh it were a rail- way train I This shunting was done effectively through a central telephone suspended in the middle of the hall. Not long after,th tephone vowputtoaremarkLble test at New- haven, Ocunacticut,ina eompayincluding members of the facelty of Yale College. The wires were extended from a telephon-e through several apartments into a room where 13Wraom stood ia two ranks The fb eaCltza* took the end of one wire, and the eighth peron in each touched vires attached to the magnet of a second instra- mcnt, tha tones of the voice being sent successfully through these 16 human bodies %vi:lloat any perceptible shock. At the Newport torpiedo statiou, in Rhode Island, speaking has been carriel on tlrough a line, iucluding five miles of submerged cable and an equal length of land wire. Siemens' resistance coils were added, 2,000 ohms it a time. until 12,000 ohms were introduced in the circuit without iazerfering with the transmission of speech. The importance of this test will be understood when it is remembered that the resistance of the Atlantic Cable is equal to 7,000 ohms only. The experiments at Newuort were continued by the addition of a total resist- ance of 30,000 ohms, but beyond 12,000 ohms the sound was found to diminish in intensity. MIr. Bell states that the ssuximus amornt of resistance through which the undulating current will pass and yot retain suffident force to produce an audible sound at tho distant end. has yet to be determine(. In the laboratory he has conversed through a resistance of 63,000 ohms. The longest length of practical telegraph line spoken through by himis from Boston to New York, a distance of 250 miles. At Montreal five telephones were recently attached to one end of a line ten miles in length, while a single telephone was connected with the other end. Spealkng end siDging from the single telephone were heard simultaneously by five listeners at the instruments in Mlontreal, and questions put indifferently through any of the fix e telephones were immediately answered from the other end of the line. Again, in the same town, a line extending from one private house to another had one telephone at one end and three telephones at the other. Two of the throe were held by singers, while the person holding the third stood on the sounding-loard of the piano. The consbined effect of vocal duet and instrumental accompaniment was distinctly heard through the single telephoneattheotherend of the line. At Hamilton, Canada, nine telephones were placed on the same circuit, on a line connecting three private houses. Speaking or singing from any one of the telephones came distinctly to all the listeners at the other houses on the circuit. " Auld Lang Syne" and "Oldl Hundred," sung at the same time at two of the bouses, were heard simultaneously at the third. On holding a telophone against the sounding board of a piano at one house, the music was enjoyed by six listeners at the other houses. On one occasion an attempt was made to speak at a distance of 125 miles, but the wire in running bcside nume- rous other busy wires stretched on the same poles, Fathered up the myriad sounds into a din that filed the telephone with the click and clang of a boiler-nmaker's rivetting shop. The voice was drowned in consequence. The telephone seems to defy distance, but requires a silent line; because of this latter fact, it has been feared that it could not be practicable over any wire having other wires for neighbours; bht within a few days a very clever electrician, Mlr. Preees, of the Post Office,has disovered a means by which this serious obstade is entirely overcome. The ftrst practical application of the telephone was made Ln May, 1877, by tho WYater Board of Cambridge, Massa- chusetts, who established telephonic communica:ion with the waterworks at Fresh Pond in order to facilitate the sending of messages. Now more than 500 houses in New England hold telephonic communmication, and more than 3,000 telephones are in operation in the United States. Gen- tlemen in their libraries give orders to clerks in their offlces, ftire brigades have called the telephone into requisition, and it is used extensively in the mines of Pennsylvania, Nevada, end California. In fact, the invention has passed out of the region of speculation, and ingenious minds are constantly finding new work for it to do. Its application in diving is already under discussion. The size of the telephone-box is of no consequence,and a complete instrunent may be made not larger than the palm of the hand. This could be easily attached to the diver's armour in a way to allow him at any time to sneak with his assistants above. Although Mr. Bell has been but a few months in Eng- gland, his invention has already commanded the attention it deserves. There has been telephonic communication between this island and Jersey; several business honses are similarly connected with private residences, and on the fifth of this month some remarkable experiments were made at the Prescot Colliery of the Wigau and Whiston Coal Company, near Liverpool, under the personal super- intendence of Sir William Thomson. In these experi- ments 600 yards of ordinary electric wire were used, the ends in one instance being at the bottom of the pit, while the other ends to which the tubes or trumpet-like orifices which resemble ordinary stethoscopes, were attached, were brought into the office of the company, which is some distance from the pit's mouth. While one of the Govern- maent colliery inspectors and others went to the bottom of the pit, the majority of the audience remained in the office. Complete success crowned the first experiment, whicn was merely to test the telephone as a means of com- munication. Questions asked in the offlce were answered in- atantaneously from the pit. Even the cheering of the colrers at a distance from the instrument was distinctly heard; and those at the lower instrument stated that they not only heard the messages forwarded, but alsothe buzz of animated conversation. The instrument was then applied to the in- dicating overhead the anemometer below. Up to the pre- sent time, the rate of the current of air in the passages of the mine could only be known by reading it off the re- gister of the anemometer. By means of the telephone the registry may be tested at any moment by a person above the mine. Deceit becomes impossible. it has been a com- mon practice to remedy insnfficient ventilation merely when the men have vwarning that an official is about to descend the shaft. The registration above is attained by having the air measarer always connected with a telephone, aud so adjusted that after a fixed number of revolutions the instrument may act on a spring which vibrates against the telephone and, seLting it in action, enables the overseer above ground to know at what rate of current the air is running in the mine. This vwas done on the 5th of November to the complete satisfac- tion of Blr. Hall, the inventor of the anemumeter. It was proved at the same time that the telephone used to register the ventilation could be also used for communication with allparts of the mine by the same wire. Given one wire and the requisite number of telephones, and a perfect record can be obained of the quantity of air going into a mine, as well as perfect communica.ion beesaablished be- tween the surface and the interior. It is hardly ossible to conceive a greater benefit to colliers than this discovery entails. During the experimentsSirWilliamThomson gave ashort lecture on the telephone to a double audience-one being in the mine and the other in the office,-expressing his amazement at the great improvement which the instrument haad undergone since trst tested by him at Philadelphia in the presence of the Emperor of Brazl. If such admirable results have been accumplished by the telephone while, ac- cordiLng to the inventor, it is still in eabryo, what may not be hoped from the future ? THE TELEPHOZVE.