The fairy tales of science/The Amber Spirit
The Amber Spirit.
Puck. "I go, I go; look, how I go,
Swifter than arrow from the Tartar's bow."
That merry wanderer of the night, Puck, who boasted that he could "put a girdle round about the earth in forty minutes," was a sluggard compared with the fairy messenger who now flies hither and thither at our bidding, with a velocity which might carry him round the globe several times in a single second. Four and twenty centuries have elapsed since Thales of Miletus evoked this nimble Spirit by rubbing a piece of yellow amber; just as the heroes of Romance summoned genii, fairies, and hobgoblins, by the friction of rings and amulets. The Greek name for amber was electron, and thus our Spirit came to be called Electricity.
The ancients were ignorant of the potency of this ethereal being; indeed, their knowledge was confined to the isolated fact that amber, when rubbed, acquired the property of attracting light bodies.
The grander manifestations of the Amber Spirit's power received a religious interpretation; thus, the forked flashes which sometimes darted through the sky were supposed to come from the hand of the mighty Thunderer, and those fiery meteors which now and then rested on the javelins of the Roman legionaries, were looked upon as omens of victory sent by the War-god.
It was left for modern philosophers to trace these great phenomena to the Amber Spirit, and to show that his presence may be detected, not only in the fossil gum which Thales imagined to be his favourite haunt, but in every particle of dust and every drop of water.
Let us now describe the cunning means which man employed to enslave this wild Spirit. Two hundred years ago, the fragments of amber were laid aside, and a large globe of sulphur was set whirling on a vertical axis, whilst it was rubbed by the hand. By this machine the Spirit was dragged from his hiding place, and made to reveal some important secrets. Flashes of light issued from this revolving globe, and balls of pith, feathers, and straw danced towards it as though endowed with life.
Sixty years later, the discovery was made that all solid bodies may be divided into two great classes, namely, those which, when held in the hand and rubbed, set free the Amber Spirit; and those which, under similar circumstances, fail to exhibit any attractive force. Amber, sulphur, and glass belong to the first class; all the metals to the second. It was also found that certain bodies allowed the Spirit to pass along them with great celerity, while others completely obstructed his passage.
Towards the middle of the last century, cylinders, spheres, and plates of glass, were substituted for the cumbrous globe of sulphur, and with these new implements man began to forge the chains which were to bind the subtle Spirit.
In the year 1746, an ingenious Dutchman actually managed to coax him into a glass bottle, coated within and without with metal,[1] but the Spirit soon escaped from his narrow prison by passing through the limbs and body of the experimentalist, who received such a violent shock that he was compelled to take to his bed. This incident, however, did not deter the philosopher from prosecuting his inquiries, and his endeavours to construct a secure prison were eventually crowned with success.
Six years after this, an American sage summoned the now docile Spirit from the clouds during a thunderstorm, by means of a boy's kite, and thus proved the identity of lightning and that force which for two thousand years was regarded as an emanation peculiar to rubbed amber.
The nineteenth century was heralded in by the announcement of a still greater fact. A learned Italian now found that he could dispense with all the old machinery of incantation, and evoke the Amber Spirit by the action of acids upon metals. He piled up alternate disks of zinc and copper, kept separate by the interposition of moistened pasteboard, and with this simple apparatus[2] he obtained absolute control over the movements of the Spirit. He compelled him to travel along metal wires of any length; to force asunder the elementary atoms of water; to bring to light substances hitherto unknown, and to perform a hundred other feats equally wonderful. The Spirit was vanquished—the lightning was chained—and man reigned supreme.
It had long been suspected that the magnet owed its peculiar properties to the Amber Spirit, but the occult relation that subsisted between them had never been detected. This mystery was now cleared up by a Danish philosopher. He caused the Spirit to travel along a wire from south to north, and beneath this wire he placed a compass-needle. The Spirit passed, and lo! the magic needle moved, and assumed a position at right angles with the wire. It no longer pointed to the north, but obeyed the peremptory mandates of the potent Spirit. New facts were soon brought to light; thus it was shown that the Spirit could render iron magnetic. A copper wire was coiled round a bar of soft iron, and our Spirit was made to run along the wire; the iron at once became a powerful magnet, and exhibited all the properties of the loadstone.
These discoveries enabled man to employ the Amber Spirit as a courier, a vocation for which he is eminently suited, as the speed at which he travels has been estimated at 288,000 miles in a second.
Let us see how our messages may be conveyed.
In London we have a pile of zinc and copper disks, or what amounts to the same thing, an arrangement of metal plates and acids which we call a battery. We have only to connect the extremities of this machine by means of a wire to set the Amber Spirit in motion, and he will continue to move as long as the connexion remains complete, but will stop the instant it is broken. His route is from the zinc to the copper through the acid solution, and along the wire back again to the zinc. He will never leave the battery at one end unless he is quite satisfied that he can re-enter it at the other, but while there is nothing to obstruct his course he will continue to circulate through the arrangement without exhibiting the least sign of fatigue.
Let the wire which connects the opposite ends of the battery be long enough to reach to Edinburgh and back; and at the northern capital let there be a mariner's compass placed so that the needle shall be directly below, and parallel to the wire. It is evident that with this simple apparatus we can compel our courier to travel to Scotland and back. Every time we connect the homeward wire with the zinc end of the battery, the Spirit will rush to Edinburgh, and cause the magic needle stationed there to move.
The deflections of this needle may be converted into intelligible signs. They can be made to spell words; thus, one movement may stand for a; two for b; three for c, and so on to the end of the alphabet.
We have said that our courier will refuse to leave the battery unless he be provided with a return ticket, or in other words, unless he can secure a safe passage home; it does not follow, however, that his homeward path must be a wire, as by a peculiar arrangement we can force him to find his way from Edinburgh to London through the earth.
We have supposed that only one kind of motion can be given to the magnetic needle, and that the Amber Spirit can only be made to travel in one direction, that is to say, from the copper end of the battery through the wire, and back again through the earth. If we connect the wire with the zinc end this direction is reversed, and, as a matter of course, the Spirit passes over the needle from north to south, instead of from south to north as before.
This new direction is at once detected by the needle, and its north pole moves to the right, whereas it had previously moved to the left. We may take advantage of this double movement in simplifying our alphabet; thus, one movement to the right may stand for a; one to the left for b; one right and one left for c, and so forth.
We will not trouble our reader with any more explanations, but will confine ourselves to a consideration of some of the ingenious methods which have been devised to render the Amber Spirit a useful messenger.
Some twenty years ago, a native of this country proposed a system of five wires, in connexion with as many needles, which indicated the letters of the alphabet at the rate of twenty a minute. Attention was to be drawn to the signals by the stroke of a bell, the hammer of which was moved by the magnetic force which the Spirit communicated to a piece of iron; thus the ear as well as the eye was to be addressed. He afterwards simplified this instrument by employing only two wires, and so increased its power that thirty letters could be indicated in a minute.[3]
In America, another philosopher was simultaneously engaged in perfecting a still more extraordinary contrivance, by means of which the Spirit was made to jot down an alphabet of dots and strokes which represented definite characters. The marks were written on a strip of chemically prepared paper, which was made to pass under a fine steel point.[4]
The Spirit had no sooner been taught to write, than man set about teaching him the art of printing. Behold him now, a master of the art, printing messages letter by letter, in the ordinary Roman characters, under the direction of an operator stationed at a distant city![5]
The Spirit's education was not yet considered to be complete—he had to acquire another accomplishment. He could communicate intelligence by means of moving needles and revolving dials, by written dots and printed characters, but he could not yet imitate the handwriting of the individual who forwarded the message. An ingenious gentleman now took him in hand, and soon made him an expert copyist. We can now write a letter, have it copied at a remote town in a minute or less, and receive a reply in our correspondent's handwriting, almost as soon as the ink is dry with which it was penned![6]
The philosopher Thales wondered to see certain minute bodies fly towards a piece of amber; but how great would have been his astonishment had some superior intelligence informed him that the invisible being which moved the particles would one day be taught to trace figures upon paper exactly like those just written by some one far away! We will not attempt to explain the action of the Spirit's magic copying-press, as it would lead us too far into the dark domain of chemistry.
A hundred systems of communication might be enumerated in addition to those we have noticed, so great has been the intellectual activity of the last twenty years.
In England, America, and many continental countries, iron wires, plated with zinc to prevent rusting, form the roads along which our ethereal courier travels. These wires are supported by wooden posts, erected some sixty yards apart on every railway; they are not permitted to touch the wood, but are passed through short tubes of porcelain attached to the posts. Were we to omit these little tubes, the Spirit would shirk his duty, and would travel no further than the first post, down which he would pass to the earth.
These aerial roads are sometimes rendered impassable by fogs, snow-storms, and heavy rains; they are, moreover, seriously affected by Amber Spirit himself when he takes the form of Lightning. During a thunderstorm everything goes wrong, and the Spirit having escaped from his thraldom, sets man at defiance. He takes possession of the wires and plays a hundred antics. The signal bells ring without ceasing; the needles vibrate to and fro, or remain for hours deflected to one side; while the printing machines strike off unmeaning rows of dots and lines, or long sentences of an unknown tongue.
In Prussia, Saxony, and Austria, copper wires, covered with gutta percha, and buried at some little depth in the ground, are employed as a means of communication. These subterranean wires are not subject to the influence of thunderstorms, but in other respects they are more troublesome than those suspended in mid air. The buried wires are greatly affected by the earth's magnetism and other disturbing influences; moreover, trenches have to be dug for their reception, and they are with difficulty reached when deranged. Thus we see that each kind of road has its peculiar advantages and defects.
As gutta percha effectually cuts off all communication between a wire and surrounding conductors, we make use of this marvellous substance to enclose the wires which convey our Spirit through the sea.
The practicability of these submarine roads was demonstrated in 1849, when a trial was made with two miles of covered wire laid in water. Soon after this a cable was constructed, which enclosed four copper wires covered with gutta percha; and by means of this cable France and England were brought within a speaking distance of each other.
The Amber Spirit soon gave proofs of his ability as a continental messenger, and on the 14th of November, 1851, our great morning journal published a despatch from Paris, dated seven o'clock the preceding evening!
Another cable was now stretched across the Irish Sea, by means of which England was able to exchange civilities with her sister isle. Others followed, and man, emboldened by their success, now began to think of despatching his obedient courier across the Ocean. Europe was covered with a network of wires, and so was America—to unite these two great systems of communication would be a feat unparalleled in the annals of Science.
This wondrous feat has at last been accomplished, and the two great Continents are now connected by a cable which lies at the bottom of the Atlantic. At Man's bidding the Amber Spirit speeds along this tremendous cable, and having registered a single letter at its further end, finds his way back to the battery through the pathless deep. Again and again he makes this extraordinary circuit, until every letter in his despatch has been registered; so that, in spelling a word of one syllable, he has to perform a series of journeys which together far exceed the length of Puck's famous girdle.
The Amber Spirit has had other duties imposed upon him besides those of a courier.
He has been taught to measure time with great accuracy, an accomplishment which scarcely seems to harmonize with his astonishing fleetness. Measuring time must be a tedious occupation to one accustomed to annihilate it; nevertheless, clocks are moved by our versatile Spirit, which have neither weights nor springs, and which will go for ever without winding.
We have seen how needles may be moved and bells rung; let us now consider how a pendulum may be set in motion. A battery is connected with a pendulum of peculiar construction, its bob being formed of a hollow brass reel on which a long copper wire covered with silk is coiled. In the clock-case, on either side are magnets, fixed so that their opposite poles enter the reel.
Our readers have already been informed that a magnet freely supported, as in the mariner's compass, will move when the Amber Spirit passes over it. We will now confide to them another secret, namely, that a fixed magnet will give motion to a moveable wire along which the Spirit is passing. We shall now be able to explain the motion of our magic pendulum.
As soon as the Spirit is sent along the coil of wire, the pendulum moves towards one side, being attracted by the one magnet and repelled by the other; but by an ingenious contrivance the connexion between the coil and the battery is now broken, and the pendulum falls back by its own weight, again to be pulled aside by the magnets. The pendulum is thus made to oscillate; and so long as there is power enough in the battery to force the Spirit through the coil, it will keep swinging, and give motion to a series of wheels acting upon each other which carry round the hands of the clock.[7]
Other methods have been devised to render the Spirit an effective time-keeper, but the simple arrangement we have described may be taken as the type of them all.
The great peculiarity of these wonderful clocks is, that they may be connected by wires, and made to keep exactly equal time, though separated from each other by hundreds of miles. With a single battery of sufficient power all the clocks in London might be kept going; and what is still more extraordinary, the London clocks might be made to regulate those of Edinburgh and Dublin, or even those of Paris and New York!
The Spirit has been employed to move more ponderous things than pendulums. He has been taught to turn a lathe, work a pump, and propel a boat through the water; but as it is much more expensive to evoke the Spirit by means of metals and acids, than to raise Steam from water, he is not likely to supersede Steam as a mover of machinery.
In the useful Arts the Amber Spirit has long been employed as a worker of metals, and with his assistance we now cast copper medallions, vases, and statues, without making use of a furnace; we gild or silver all kinds of utensils, and cover the most delicate productions of nature with thin films of metal. We will proceed to consider these mysterious operations. When the Spirit is made to travel through a solution of copper, silver, or gold, he decomposes it, and deposits the metal, particle by particle, on the wire which conducts him back to the battery. Now by attaching a suitable model or mould to this wire we can procure this metallic deposit in any shape, and by substituting any utensil for this mould, we may cover it with a film of gold or silver.[8]
We have not done full justice to our Spirit's abilities, as we have omitted to mention the many services he has rendered to the astronomer, the geographer, the chemist, and the physician; we have said enough, however, to give the reader an idea of his versatile powers.
We have shown that he can travel with the rapidity of thought across a continent or an ocean; that he can write and print our messages in the most distant places; that he can measure time as it flies, move all kinds of machinery, and melt copper in cold water. We may search through our old fairy tales and romances in vain to find a spirit capable of performing such miracles as these.
- ↑ The Leyden Jar.
- ↑ The Voltaic Pile.
- ↑ Wheatstone's Telegraphs
- ↑ Morse's Telegraph.
- ↑ Bain's Printing Telegraph.
- ↑ Bakewell's Copying Telegraph.
- ↑ Bain's Electric Clock.
- ↑ The Electrotype.