Caption under the image on this page: ELECTRIC LIGHT AT SEA
"MIRACLES OF SCIENCE" OR FOUR NEW WONDERS OF THE WORLD --- 1876
The "miracles of science," or the "four new wonders of the world," is the
familiar phraseology with which those remarkable achievements in the world of discovery and invention ---the Electric Light, the Telephone, the Phonograph, and the Microphone, --- are referred to, and the American citizen may well speak with pride of those accomplishments, from the fact that they are, either exclusively or in the most promising sense, the offspring of his own native land. The first of these, the electric light, which has recently attracted such attention as never before was bestowed upon it, has been aptly pronounced the brightest meteor that has flashed across the horizon of promise during the present century, --- and, indeed, the splendor of the rays emitted, and the representations of the small cost required to produce such an intense illumination, have led many to believe that gas-lighting was drawing to a close, and that night would be turned into day by this wonderful agent.
The evident priority of American genius in this line, it is safe to assert; though not alone in this country, but in Europe as well, electricity has been successfully employed in lighting assembly halls, factories, depots, streets, parks, lighthouses, etc., --- and is adaptation for marine purposes, as exhibited in the accompanying illustration, is looked upon as likely to mitigate the perils of light and of fogs, and increase the facilities of ocean enterprise.
The inventions claiming to realize the best results in this direction are very numerous, and constantly accumulating. Acknowledging, as do all men of science, the practicability of the thing when applied on a large scale, and especially out of doors, the desideratum of chief importance has seemed to be its application to in-door service. That this was accomplished by Prof. Farmer, at his home in Salem, Mass., in 1859, is abundantly demonstrated. To realize this object conveniently, agreeably, abundantly and inexpensively, many contrivances have been brought forward, foremost among which may be said to be those due to the wonder-working brain of Mr. Edison.
This invention, as summarily described by Mr. Edison himself, consists, first, in the combination with an electric light of a thermal circuit regulator to lessen the electric action in the light when the maximum intensity has been attained; the combination with the electric light of a circuit closing lever, operated by heat from the electric current or from the light, and a shunt or short circuit to divert the current or a portion thereof from the light; the combination with the electric light and a resistance of a circuit closer operated by heat, and serving to place more or less resistance in the circuit of the light; the combination with an electric light of a diaphragm operated by the expansion of a gas or fluid in proportion to the temperature of the light, to regulate the electric current; the combination with a vibrating body, similar to a tuning fork, of mechanism for maintaining the vibration and magnets, cores, and helices, by means of which a secondary current is set up, so as to convert mechanical motion into electric force, or the reverse; and, finally, the combination with the electric lights of means for regulating the electric current to the same, in proportion to the heat evolved in the light, so as to prevent injury to the apparatus. His improved alloy of the refractory metals, and the thermo-static regulator, are the means, in this case, of securing a light which is alleged to be the most steady, clear, inexpensive, and reliable, of any electric light yet proposed. In other words, the plan consists in placing an electric light in branch circuits passing across from the positive to the negative conductor, and the lights are controlled by switches which connect the branches with or disconnect them from the main conductors. The lamp consists of a suitable standard, surmounting which is a transparent glass case, resembling an ordinary lamp chimney, except that it is closed at the top; within this is suspended a spiral of metal wire, hardly larger than a knitting needle in diameter, and about three-quarters of an inch in length. When the electricity is turned on, this spiral glows with a white light, of great brilliancy and steadiness. Should the sanguine expectations of the inventor of this device be realized, a revolution in artificial illumination, especially in-doors, will indeed take place, involving, practically, the disuse of every other method and material.
Already, in this country and in Europe, the various arrangements for electric illumination which have seemed the most practicable have been put into operation, with various degrees of success, and, in the case of large inclosures or areas, there appears to be no doubt as to its superiority. For light-houses, it has some valuable points of adaptation, and for various purposes at sea its employment must be found extremely serviceable. The results of its introduction in the light-house at South Foreland prove its usefulness in this relation. The electric current for this light is generated by means of large magneto-electric machines, which are driven by belting connected with a steam-engine, each machine being composed of ninety-six helices, mounted upon six gun-metal wheels, each carrying sixteen helices; between these wheels are placed the magnets, eight in each division, forty of which are composed of six layers or leaves riveted together, while the sixteen end ones have but three leaves each. The magnets, which are mounted in frames, are stationary, while the helices revolve at the rate of four hundred revolutions per minute. The power absorbed by the electric machine alone, including friction, is four indicated horse-power. The power of a magneto-electric machine is according to the gross attractive power of its magnets, each magnet having a certain lifting or attractive power expressed in pounds. In the machines at South Foreland, each of the six-plate magnets lift one hundred and eight pounds, and each of the three-plate magnets fifty-four pounds, making the attractive power of the magnets, in one machine, 5,184 pounds. Each of the six-plate magnets weighs forty-three and one-half pounds. The machines are connected by underground cables with the electric lamps placed in the lenses of the tower.
The success which has attended the use of such machines or devices as the Lontin, Gramme-Jablochkoff, Rapieff, Werdermann, DeMeritens, Siemens, Wallace Farmer, Sawyer-Mann, Brush, Fuller, and some others, shows that, whatever may come of the efforts to secure the convenient and economical use of electric illumination in dwellings, there can scarcely be a doubt, as has already been remarked, of the substitution of this system for all others, at no distant day, outdoors and in halls and other public buildings of considerable size. Quite a large number of one of the devices just mentioned have for some time past been in operation in some of the largest business and industrial establishments in the United States; the teSts of power absorbed by this apparatus, taken with a dynamometer, shows 13 85/100 horse-power, the number of lights being sixteen to seventeen to a machine, each light being of two thousand candle power.
The details of the scientific principles and of the mechanical intricacies involved in these various remarkable inventions would cover many pages. It may be stated, therefore, generally, that the carbon points of a powerful machine for electric illumination are equal to the sun in lustre --- it is thought possible, indeed, that even this limit may be overpassed, as the sun does not occupy the first position in the universe. In quantity and quality, too, the electric light greatly exceeds all flames; it is, in fact, precisely this immense profusion of illuminating power that has proved objectionable. Nothing is easier, however, than to reduce the lustre of the light to any degree that may be desired --- that is, by covering the arc with a large opalescent globe, which, while hiding the light, receives all the rays, and disperses them in the same way as if the globe itself were luminous. To be suitable for purposes of illumination, a light should contain, according to chemical authority, the seven primitive colors of the spectrum in certain proportions; the flames of oil and gas do not contain the true proportions of these, which is the cause of their inferiority. The electric light is white --- absolutely the same as that of the sun --- and contains all the simple rays in the same proportions. The subdivision of the light, as it is termed, to accomplish which inventors have put forth the most ingenious endeavors, is one of the claimed peculiarities of Edison's device, a single machine being thus utilized for the production of several smaller illuminators, instead of for one large volume of light.
We come now to the TELEPHONE, the patent for which wonderful device was taken out at Washington, in March, 1876, by Prof. A. G. Bell, affording fresh evidence of the versatility of American inventive genius. Though habitually sensitive to the honor and claims, in this direction, of its own countrymen, the London Westminster Review frankly admits that, of all modern inventions connected with the transmission of telegraphic signals, the telephone has deservedly excited the most widespread interest and astonishment, --- an instrument which undertakes not only to convey intelligible signals to great distances without the use of a battery, but to transmit in fac-simile the tones of the human voice, so that the latter shall as certainly be recognized when heard over a distance of hundreds of miles, as if the owner were speaking to a friend at his side in the same room. The telephone --- as the tens of thousands now in use show --- does all this.
This marvelous little apparatus produces, as already remarked, cheap and instantaneous articulate communication, that is, by direct sound, --- neither battery, nor moving machinery, nor skill being required, but merely the voice of ordinary conversation, and attentive listening. It conveys the quality of the voice, so that the tone of the person speaking can be recognized at the other end of the line; it enables the manufacturer to talk with his factory superintendent, and the physician with his patients; establishes instantaneous intercourse between the main and the branch office, the home and the store, the country residence and the stable or any part of the grounds, the mouth of the mine and its remotest workings, --- in fact, between any two points miles apart.
In its mechanism, the telephone consists of a steel cylindrical magnet, about five inches long and three eighths of an inch in diameter, encircled at one extremity by a short bobbin of wood or ebonite, on which is wound a quantity of very fine insulated copper wire. The magnet and coil are contained in a wooden cylindrical case. The two ends of the coil are soldered to thicker pieces of copper wire, which traverse the wooden envelope from one end to the other, and terminate in the binding screws at its extremity. Immediately in front of the magnet is a thin circular iron plate; which is kept in its place by being jammed between the main portion of the wooden case, and a wooden cap carrying the mouth or ear trumpet. These two parts are screwed together. The latter is cut away at the centre so as to expose a portion of the iron plate, about half an inch in diameter. In the experiments made to determine the influence of the various parts of the telephone on the results produced, and their relations to each other in obtaining the best effects, iron plates were employed of various areas and thicknesses, from boiler plate of three-eighths' inch to the thinnest plate procurable. Wonderful to relate, it appeared that scarcely any plate was too thin or too thick for the purpose, though that of the ferrotype plate used by photographers seemed preferable, thin tin plate also answering very well. To accomplish the purpose sought, the iron plate was cut into the form of a disk, about two inches in diameter, and placed as near as possible to the extremity of the steel magnet without actually touching it, --- the effect of this position being that, while the induced magnetism of the plate amounted to considerable, it was susceptible to very rapid changes owing to the freedom with which the plate could vibrate. Good results are obtainable by means of a magnet only an inch and a half long, and a working instrument need not be too large for the waistcoat pocket. There is no difference between the transmitting and the receiving telephone, each instrument serving both purposes. As already remarked, no skill or training is required for the effective use of the instrument, --- the operator has merely to press the apparatus to his ear to hear distinctly every sound transmitted from the distant end. For this, it is true, an effort of attention is required, and some persons use the instrument at the first trial with more success than others. Individuals differ in the facility with which they are able to concentrate their attention on one ear, so as to be practically insensible to what goes on around them; but this habit of attention is readily acquired, and, when once acquired, the telephone may be used by any one who has ears to hear and a tongue to speak. In sending a message, the instrument is held about an inch in front of the mouth, and the sender merely talks into the mouthpiece in his ordinary natural manner. The words are repeated by the instrument at the other end of the circuit with the same pitch, the same cadences, and the same relative loudness; one voice is readily distinguished from another, the character of the speaker's voice being faithfully preserved and reproduced. Other instruments of this nature, or improvements upon it, brought forward by Gray, Dolbear, Edison, Phelps, and others, cover substantially the same general principles of construction and method.
Following closely in point of time, and, if possible, really eclipsing in wonderfulness the invention just named, is Edison's PHONOGRAPH, discovered purely by accident, --- a simple apparatus, consisting, in its original mechanism, of a simple cylinder of hollow brass mounted upon a shaft, at one end of which is a crank for turning it, and at the other a balance-wheel, the whole being supported by two iron uprights.
In front of the cylinder is a movable bar or arm, which supports a mouthpiece of gutta-percha, on the side of which is a disk of thin metal, such as is used for taking 'tin-type' pictures. Against the centre of the lower aide of this disk, a fine steel point is held by a spring attached to the rim of the mouthpiece; an india-rubber cushion between the point and the disk controls the vibration of the spring. The cylinder is covered with a fine spiral groove running continuously from end to end.
In using the Phonograph, the first operation is to wrap a sheet of tin-foil close around the cylinder; the mouthpiece is then adjusted against the left-hand end of the cylinder so closely that the vibration of the voice on the disk will cause the point to press the tin-foil into the groove, making minute indentations resembling, on a very small scale, the characters of the Morse telegraph. The cylinder is moved from right to left by the screw crank, so nicely adjusted that the steel point is always against the centre of the spiral groove. While turning the crank, the operator talks into the mouthpiece in a voice slightly elevated above the ordinary tone of conversation. Every vibration of his voice is faithfully recorded on the tin-foil by the steel point, the cylinder making about one revolution to a word. In order to reproduce the words --- that is, to make the machine talk, --- the cylinder is turned back, so that the steel point may go over the indentations made by speaking into the mouthpiece. A funnel, like a speaking trumpet, is attached to the mouthpiece, to keep the sounds from scattering. Now, turning the crank again, every word spoken into the mouthpiece is exactly reproduced, with the utmost distinctness, to the astonishment and delight of the hearer. Thus the disk is either a tympanum or a diaphragm, as the case may be, the first when it listens, the second when it talks. Of course, the original device would, true to the characteristic of American inventive genius, he carried forward from step to step, in its mechanism and capabilities. It soon became a beautiful construction, nothing being lost sight of in the way of devices for quick adjustment and in respect to other details. Among the improvements which soon followed was that of a mica diaphragm in place of the original disk of metal, this having been found to obviate the objectionable metallic tone of the sound noticeable in the original machine.
Among the facts or results which the inventor claims to be realized by this wonderful apparatus, are --- the captivity of all manner of sound-waves heretofore designated as 'fugitive', and their permanent retention; their reproduction with all their original characteristics at will, without the presence or consent of the original source, and after the lapse of any period of time; the transmission of such captive sounds through the ordinary channels of commercial intercourse and trade in material form, for purposes of communication Or as merchantable goods; the indefinite multiplication and preservation of such sounds, without regard to the existence or non-existence of the original source; the captivation of sounds, with or without the knowledge or consent of the source of their origin. These five features may well be said to constitute a mechanical marvel hitherto undreamed of. Indeed, the instrument was in no sense the child of design or even forethought. In experimenting with the telephone, Edison happened to notice the manner in which the disks of that contrivance vibrated in accordance with the breath used in speaking. Believing these vibrations could be recorded so as to be reproduced, he set to work to manufacture a machine for the purpose, the result being the phonograph, --- an apparatus that will faithfully record and repeat every syllable uttered, with all the peculiarities of vocalization or articulation, that will sing, whistle, sneeze, cough, sigh, echo, &c., &c.
With the improvements upon the Phonograph already in progress, --- among which is that of impelling the apparatus by clockwork or machinery suited to the special purpose to which it is to be put, --- some of the expected applications, as enumerated by the inventor, are those of letter-writing and other forms of dictation, books, education, public or private readings, music, family record, also such electrotype applications as books, musical boxes, toys, clocks, advertising and signaling apparatus, speeches, etc. Of the first of these uses, (and which may be said to illustrate representatively the ingenuity involved in the adaptation of the contrivance to other specialties), the general principles of construction adopted by Mr. Edison consist in having a flat plate or disk, with spiral groove on the face, operated by clock-work underneath the plate, the grooves being cut very closely together so as to give a great total length to each surface --- close calculation showing the capacity of each sheet of foil upon which the record is had to be in the neighborhood of forty thousand words. Allowing the sheets to be ten inches square, the cost would be so trifling that but one hundred words might be put upon a single sheet economically, the chief point to be effectuated by experiment in this case, being, of course, that each sheet have as great capacity as possible. This form of Phonograph for communications Mr. Edison characterizes as very simple in practice. Thus, a sheet of tin-foil is placed in the phonograph, the clock-work set in motion, and the matter dictated into the mouthpiece, without other effort than when dictating to a stenographer. It is then removed, placed in a suitable form of envelope, and sent though the ordinary channels to the correspondent for whom designed, --- he, placing it upon his phonograph, starts his clock-work and listens to what his correspondent has to say; inasmuch, then, as it gives the tone of voice of his correspondent, it is identified, and, as it may be filed away as other letters, and at any subsequent time reproduced, it is a perfect record.
A kindred instrument, in some respects, with the preceding, --- and like that a genuine marvel,--- is the MICROPHONE, or transmitter of sound, by the use of which, a mere touch, or so small a sound as the tick of a watch, for instance, may be heard at the distance of miles, and the walking of a fly resembles the tramp of an elephant or the tread of a horse on a rough road. The telephone brings the sound from a distance, and the microphone magnifies the sound when it is thus brought near, --- thus rendering the latter just as applicable to the sounds transmitted from London or Dublin to New York, if transmissible so far, as to the sounds in a vibrating plate which is within a few inches of the listener's ear. The invention depends on so breaking, by the interposition of charcoal permeated by fine atoms of mercury, the currents transmitted by the telephonic wire, that the sound is vastly increased by the interruption --- just as heat is known to be vastly increased by a similar interruption of a current, even to the turning of metallic wire to a red or white heat. Thus the microphone will make a minute sound audible, whether it be close or far off.
In Edison's pile instrument, a piece of cork is fastened to the diaphragm, and presses upon a strip of platinum which is attached to a plate of copper; the latter is one of the terminals of an ordinary galvanic pile. The other terminal slate presses against the metallic frame of the instrument. When the pile is included in a closed telephone circuit, it furnishes a continuous current, the strength of this current depending upon the internal resistance of the pile and its polarization, and these are varied by vibrating the diaphragm; the pile is composed of alternate plates of zinc and copper, and a bibulous medium between the pairs of plates.
A simple form of microphone, also, is constructed with a wooden diaphragm one-eighth of an inch thick and four inches square, this being glued to a narrow frame supported by suitable legs. Two pieces of battery carbon are secured by means of sealing wax to the diaphragm, about an inch apart, and at equal distances from the centre. They are both inclined downward at an angle of about thirty degrees. One of the pieces of carbon is longer than the other, and has in its under surface three conical holes, made with a penknife point, which are large enough to receive the upper ends of the graphite pencils, the lower ends of the pencils resting in slight cavities in the lower carbon; these pencils are simply pencil leads sharpened at both ends and placed loosely between the carbons, --- they are also inclined at different angles, so that the motion of the diaphragm which would jar one of them would simply move the others so as to transmit the sound properly.
The development or conception of the microphone is stated to have been as fortuitous as the discovery of the phonograph. Thus, in the Hughes device, the Professor was led by his experiments to place a small electric battery in circuit with the telephone. He was surprised to find, on adding weights to a fine wire through which the current was flowing, that, just before the breaking strain was reached --- just when the fibres of the metal were torn asunder --- a peculiar rushing sound was observable in the telephone. He then tried whether he could reproduce this noise by loosely binding the wires again together, and he found that by this means he had hit upon a wonderfully sensitive detector of sounds, --- any noise near the wires being immediately taken up by the telephone with startling distinctness. The slightest attachment of the wires procured the same results, and then the joined wires were modified into an apparatus which merely consisted of three nails, two being parallel and connected with the battery wires, and the third resting upon them. Although this ridiculously simple arrangement was capable of transmitting all kinds of noises to a distant place, the sounds were confused. This led to experiments with different conducting substances, the most reliable results, however, being obtained from the various forms of carbon. An arrangement was then devised which not only proved successful, but so sensitive, in fact, as to be almost beyond control, namely, a tiny pencil of fine gas coke dropped into indentations in two blocks of the same material. This compact little instrument, fastened to a cigar box, it was found would transmit to a long distance the ticking of a watch placed near it, --- the gentle touch of a feather, or a camel's hair pencil, reached the ear as the rasping of a file, while the scratch of a quill pen in the act of writing was augmented to a loud noise. But better than this form, of course, is that of a base board about three inches long, having screwed upon it two little angle pieces of brass plate, and a metallic bar, pivoted on to these brass supports, with a piece of carbon at its end; this carbon block rests upon two similar pieces kept together by a cloth hinge placed at the side, and the lower block, to which one of the battery wires is attached, is fastened to the board; the pressure upon these carbon surfaces is controlled by a delicate spring of brass wire, which is attached to a screw with a milled head. By turning this screw, the pressure is nicely adjusted, from the very light contact required for delicate sounds to the comparatively heavy pressure wanted when the sounds are more intense. But, to describe this marvelous instrument in the various forms of construction already given to it by inventors at home and abroad, notwithstanding its recent introduction, would require scores of pages.