From the 1924 book, A Popular History of American Invention. Original chapter title, “The Rise of Electricity.”
THE FIRST SPARKS
THE history of the rise of electricity is every whit as fascinating as the story of Aladdin’s lamp. Aladdin rubbed his lamp and all things were possible of accomplishment. Today we press a button to achieve similar wonders. From the days of Thales, 600 years before Christ, to the time of Benjamin Franklin, the world’s philosophers and inventors were busy briskly rubbing amber, sulphur balls, and pieces of glass, and getting wonderful electric sparks. Their simple experiments one may repeat now on a dry, cold day by chafing a hard-rubber penholder on the sleeve of one’s coat, or by merely shuffling one’s feet on the carpet.
Most of us have lit a gas-jet with finger-tip sparks. That spark has greater magic than Aladdin’s lamp. The lamp and its owner were unreal. The electric spark is omnipotent, its power everlasting. Inventors, experimenting with electricity, soon noted that this “frictional” electricity could be “conducted” from one place to another; and Stephen Gray, in England, about 200 years ago, began sending the current hundreds of feet over circuits of packthread held up by silken loops, or “insulators.” Living at a famous London charity school, Gray, as a poor pensioner, was glad to get the inexpensive help of the boys for his queer experiments.
While the youngsters were doubtless scared, they must have found Gray’s experiments more amusing than their school lessons, especially as there were such things to handle as a hot poker, a live chicken, a big map, and one of those new, fashionable articles, an “umbrella.” The boys were hung up in the air, and electrified. They blew soap-bubbles to which the “charge” jumped from their toes or their noses. When they got tired of bobbing around in loops of hair, like trapeze performers, they were stood up on cakes of resin and charged and discharged, all crackling and sparkling, until that gloomy playground of the grimy old Charterhouse School anticipated a dazzling comic scene at the Hippodrome in modern New York. The show was free to anybody who would poke his head through the stone gateway.
C. F. Dufay, in France, repeated these experiments and sent electricity over a wet string 1,256 feet long, and was merciful enough to use only one child. He found there were two kinds of electricity, which he called “vitreous” and “resinous,” names that stuck long after scientists began to use the terms “negative” and “positive.” He saw that like electricities repelled each other, while unlike electricities attracted. He also used solid insulators of Spanish wax, in place of silken loops, to hold up his circuit of thread. Dufay noted that bodies might be electrified either by direct touch or by “induction” through the air, and he conceived the clever idea of a whirl or “field of force” around his glass tubes, on which there was a charge of static electricity, due to the same old rubbing.
|Charles Duffy Demonstrates Electricity.|
Cheered by friendly advices from the great Frenchman, who founded the famous Botanic Gardens in Paris, poverty- stricken Gray in his humble Grey Friars’ shelter, went at it again, overworking his little collection of accessories, which now included tea-kettles, fishing-rods, a “pint pot,” pewter plates, and a sirloin of beef—not forgetting the small boys, wincing as they felt the sparks through their woolen stockings. Above all, Stephen Gray hoped that a way might be found “to collect a greater quantity of electric fire.” Like others, he was impressed by the crackles, the “brushes” of flame, glows, and ”rays of light,” and he set it down in memorable black and white, that the force he was demonstrating seemed, comparing small effects with great, “to be of the same nature with thunder and lightning.”
EARLY ATTEMPTS AT HARNESSING ELECTRICITY
The boys, handy to philosophers, must have had an uncomfortable time while sparks of greater size, sting, and dazzle were being obtained and tested. Eventually the electricity obtained from the frictional machines was actually “stored.” A Scottish monk, Gordon, teaching in Germany, soon after Gray’s death, in 1736, invented the first electric bell. It had two little gongs, between which hung a metal ball on a silken pendulum. The charged ball struck one gong, gave up its electricity in doing so, and, being repelled, struck the other gong; so on, over and over again.
Gordon, perhaps more of a mechanic than a monk, then invented a tiny motor. It was a metal star pivoted at its centre with the ends of its rays slightly bent aside all in the same direction. The reaction of the electric discharge kicked the star around on its pivot. This same monk, Alexander Gordon, was also the inventor of electrocution; for he killed many chaffinches with a smart discharge from his frictional machine, by which same principle Thomas A. Edison, about a century later, got rid of the cockroaches when they came uninvited to eat his supper as he worked at the night operator’s telegraph-key in Boston.
Following Gordon’s discoveries, the stage had arrived where electricity became useful to man rather than serving him merely as a medium for philosophical diversion. Up to the middle of the eighteenth century, practically only one really useful invention, the compass, could be attributed to the discovery of magnetism.
A period of electrical invention had now dawned, and continuing his excellent experiments, Gordon ignited spirits by contact with a jet of electrified water. Many an American fireman, fighting flames, has since then found that the stream thrown against a burning building could carry inversely at the same time, a deadly current back to him from some adjacent bare wire.
Not to be outdone by Gordon, a clever apothecary in London, named Watson, set fire to hydrogen with the electric spark, just as gas is now ignited in automobiles. Watson also exploded gunpowder and fired a musket after this fashion, thus being the first inventor of a vast range of various methods for electrically detonating explosives, mines, torpedoes, and other industrial and warlike devices.
Out of all these inventions, one stood out by reason of its greatness. It was called the “condenser.” As often happens when there is a wave of invention along a particular line, several men claimed the condenser to be the product of their individual genius. In the maze of electrical experiments of this period, it is hard to decide whose claim was the most justifiable. Probably two or three hit upon the identical idea simultaneously.
|The Leyden Jar was an early form of a capacitor and could store electrical energy.|
In Leyden, Holland, Pieter Van Musschenbroek, in 1746, having noted that electrified bodies lose their charge, conceived the idea of bottling a quantity of it for preservation. To do this he decided to electrify some water in a jar. The experiment, though absolutely successful, almost resulted in disaster. While his assistant was disconnecting the communicating wire, Van Musschenbroek received a nasty shock in his arms and chest as all the stored static electricity ferociously leaped out at him. The astounded professor instantly indulged in language which had nothing to do with scientific research, and he wrote to his friend René Réaumur, the famous French physicist, that he was literally all broken up and would not chance another such shock for a kingdom.
In 1745, Dean von Kleist had done just about the same thing with a medicine bottle, and perhaps, as we say to-day, the patent should have gone to him. Watson, however, put some neat touches on what ever since has been known as the “Leyden jar,” by coating it inside and out with tin-foil. Then came some magnificent experiments to close this whole series of observations and investigations, extending over a period of two thousand years. In France, the Abbé Nollet took a company of the king’s soldiers, joined their hands to form the circuit, then knocked them over like human ninepins with a shock not far inferior to that which the dough-boys got in the late war when they ran into some “live” barbed-wire entanglements set up by the foe. In England a committee of the Royal Society sent an “electrical commotion” from the “charged phial” over “wire” circuits set upon “dry sticks”; circuits of a total length of four miles, inclusive of water in large ponds. Then came Benjamin Franklin.
FRANKLIN DRAWS THE LIGHTNING FROM THE SKY
It has been forcefully said that Franklin’s proof of the identity of man-made frictional electricity with the electricity of the thunder-storm subdivided history much as the birth of Christ subdivided the forms of worship. Franklin snatched the lightning from the sky with a bit of a kite and a silk handkerchief stretched on two light strips of cedar. In Philadelphia to-day, in a dingy old building, one may still see Franklin’s glass-globe friction-machine, made in America, with the aid of which and other quaint appliances he pioneered in the detection of many new electrical principles and phenomena.
With his six-gallon Leyden jar he knocked out six men at one discharge. The only pity is that instead of giving all his time to the study of electricity, Franklin was able to devote to it barely nine years of his life. He was interested in so many things: printing, books, libraries, schools, and, above all, politics. Many million American citizens to-day are toasting their shins in front of Franklin stoves, reading Franklin journals, putting money into Franklin savings-banks, and using Franklin post-office facilities. He dearly hated King George of England, and it is interesting to recall that his remote predecessor, Thales the Grecian, fell out of royal favor “by being too free in his opinions concerning monarchs.”
Franklin, as early as 1750, imitated the effects of lightning before catching and taming it. Moreover, experimenting with ship compasses, “we have frequently given polarity to needles and reversed it at pleasure.” In 1752, primitive Franklin lightning-rods were stuck up in France, and without fail they became electrified, though it was not shown that the aerial lightning had done it. To Franklin himself was fitly left the supreme proof. In June, 1752, he sent up his toy kite. A sharp-pointed wire stuck out and above from its upright crossbar of wood. To the twine of the kite-string, a silk bow was tied at the land end, and a key was knotted into the bow. Sheltered in a doorway to keep the silk bow dry, Franklin and his son, a youth of twenty-two, amid the sharp shower of rain, flagged the oncoming thunder-heads. Soon the loose filaments of the twine stood out like porcupine quills, a finger could attract them, and before long the key sparked briskly when touched by Franklin’s knuckle. The daring experiment was a success!
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|Left—BENJAMIN FRANKLIN, THE FIRST AMERICAN ELECTRICIAN. Right— Michael Faraday, “THE GREATEST EXPERIMENTER WHO EVER LIVED”, discoverer of electrical induction, the basis of the modern generator, motor, telegraph, telephone, and radio communication. Du Bois Reymond regarded him as “the greatest experimenter who ever lived.”|
Electricity from the very skies was thereafter stored in Leyden jars as easily as if it had come from a friction-machine, and all the familiar effects were produced with unbelievable success. Franklin, to make conviction doubly sure, showed that the distant clouds were sometimes charged positively, sometimes negatively. The next great step was the invention and universal use of lightning-rods to protect buildings. Franklin, as a human lightning-rod, had challenged death in making one of the greatest discoveries and inventions possible to mortal man. Fourteen months later, a physicist at St. Petersburg, Russia, having put up a plain iron rod to collect the electricity of the heavens, and trying to read the indications of an “electrometer,” forming part of his apparatus, was hit by a globe of blue fire from the rod, which killed him as swiftly as would a bullet from a pistol. The truth is that Franklin’s is one of the most remarkable cases of good luck on record.
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|FRANKLIN’S KITE EXPERIMENT. Franklin’s kite experiment proved that lightning and laboratory electric sparks are tne same in nature. Theoretically Franklin ought to have been killed. One of his imitators in Europe fell a victim to similar daring.|
It must be clearly understood, however, that the Thales, Watson, and Franklin kind of electricity is of little practical value or use, except in radio. We cannot light electric lamps, run trolley-cars, or work electric motors by sparks from rubbed glass, or even by captive lightning. The great tasks that electricity now performs for mankind need a steadily flowing stream of energy; in other words, a current. And we now proceed to narrate how the current came to be generated and applied.
THE DISCOVERY OF THE ELECTRIC CURRENT
Luigi Galvani could hardly understand why Franklin wanted to toy with the thunder-clouds when electricity was all around and even in us. Although his reasoning was profound, Galvani was seemingly unable to apply it successfully. The Italian physician, father of modern medical electricity, was one of those men who try to find out more than books can teach them. In order to get a better understanding of the human body, he studied the muscles, nerves, and bones of birds, frogs, and other small animals. He was keenly interested in electricity, and of course had a friction-machine, similar to the one used by Franklin. He also knew that the “electric eel” and other fishes could give a severe shock.
One day, in 1786, Galvani was working over the legs of a skinned frog, when an assistant started to spin the electric machine which stood on the same table. The dissecting knife Galvani was using happened to touch one of the wires of the machine. Instantly the frogs’ legs kicked in the most lifelike manner. This gave Galvani an idea. “If an electrical charge can make the legs of a dead frog act as though they were alive,” he thought, “they must have been charged with electricity when they were alive. Therefore, electricity must be the thing that makes us live.”
If this were true, it was indeed a most important discovery. Galvani became eager to prove it. During the course of one of his experiments, he fixed the legs of a frog to a copper hook and hung the hook on an iron railing. But no sooner had the two metals come into contact than the legs kicked vigorously. Here was something even more extraordinary. This time there was no electric machine around. Why did the legs kick? “Because,” said Galvani, highly delighted, “these legs are so fresh, they are still full of electricity! My theory is correct!” He immediately wrote a book on the subject, and soon frogs’ legs were kicking in every laboratory in Europe.
Most of the scientists who thus amused themselves believed what Galvani told them. But there was one man who tested the truth of everything for himself. This was Alessandro Volta, who taught science in the Italian University of Pavia. In 1789 he studied this strange kicking very carefully, and gradually made up his mind that the electricity was caused by the contact of the two different metals, and not by the frog.
Galvani was very angry. “You are wrong!“ he wrote to Volta. “I have proved that electricity is life.”
“I am not wrong,” replied Volta, “and I’ll prove it by producing electricity with metals only, and without frogs’ legs!“
Volta then took a number of silver coins, made an equal number of zinc disks of the same size, and piled them alternately one on top of another, with pieces of moist cloth in between. He fastened wires to the top and bottom of the pile, and when he joined the two wires together, he produced, for the first time, a steadily flowing current of electricity. This he accomplished about 1799.
|THE FIRST ELECTRIC CELL. Volta’s first battery or voltaic “pile,” made in 1800, consisted of a number of silver coins and equal number of zinc disks of the same size. The silver and zinc disks were piled alternately on top of one another, with pieces of moist cloth between the disks. Wires were fastened to the top and bottom of the pile, and when they were joined, Volta obtained a steadily flowing current of electricity. Thus did electrical engineering begin. Courtesy General Electric Company.|
Why an electric current should be produced by the contact of two different metals we do not as yet know. But that it is produced in this way, can easily be proved. Touch the underside of your tongue with a silver coin and the upper side with a steel key. Then bring the outer parts of the coin and the key together. You will notice a distinctly sour taste that is different from the flat taste of either metal by itself, and your tongue will tingle for several minutes afterward. This sourness is caused by a feeble electric current, which flows when two different metals are placed in contact with moisture. Volta’s “pile” was the first electric battery. It is one of the most important inventions ever made, for it gave us the electric current. It aroused little interest, however, and when it was demonstrated to the great Napoleon he was unable to see any value in it, though its power was infinitely greater than that of his whole army.
Volta’s pile was soon greatly improved. Everybody imitated it for purposes of experiment and research, and a considerable number of different kinds of batteries were invented. These batteries opened up an entirely new field of knowledge, and discovery quickly followed discovery.
One of these discoveries was the ability of the electric current to break up certain substances, such as lime, which no chemist had been able to analyze. In this way, a number of previously unknown chemical elements have been obtained in their pure state, one after another, down to this day. Electrochemistry is one of the great new arts thus founded.
THE RELATION BETWEEN ELECTRICITY AND MAGNETISM
The electric current was a link, like the Panama Canal, between two great oceans: electricity and magnetism. These vast realms the electric current joined and converted into one inseparable body.
Human acquaintance with the effects of the lodestone, or natural magnet, is as ancient as the knowledge of the properties of amber. Magnetic iron ore, or magnetic iron sand, may be found in all parts of the world, and the appreciation of its mysterious power seems always to have been common. Sir Isaac Newton, the discoverer of gravitation (the magnetic pull that all the heavenly bodies exert upon one another through space), had a finger-ring in which was set a three-grain magnet that would lift 700 grains of iron. Long before the science of magnetism was academically established, the corroborative fact had been observed that magnets had polarity.
At least a thousand years ago, sailors depended on the use of the compass, a noble invention of the highest rank. An iron needle that had been rubbed by a natural magnet was put on a pivot, or floated in a bowl of water, so as to swing around, indicating north and south, as well as east and west, when it came to rest. Easy to falsify, one who tampered with it, if detected, met a punishment that fitted the crime; his hand was nailed to the mast, or he was “keelhauled” under the ship, or thrown overboard. The Dutch mariners added the familiar point-card to the compass.
Columbus, who without the help of his compass would never have discovered America, noticed that it did not always point exactly to the true north. His solution was that the needle had not received the proper magnetic rubbing; but in this he was wrong. For the most part, the theories of the magnet and the compass were mere guesswork in those days, and no real ideas or inventions of profound importance came for two hundred years. The best of the investigations were those of the English physician, Gilbert, about 1600, whose splendid work, De Magnete, was an addition to scientific research. Progress, however, was slow until the immortal discoveries, in 1819, of Hans Christian Oersted, professor of natural philosophy in the University of Copenhagen.
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There was such a similarity between the separate accomplishments and properties of electricity and magnetism, that it would have been curious if, by 1800, somebody had not guessed they were closely related. Hans Christian Oersted, with grim determination and patience, set out to prove it. He was a rather clumsy experimenter, but possessed with the right idea. Even though his magnetic needle did not at first respond to the flow of current from a voltaic cell, he stuck to his discouraging task.
Finally, in 1819, he and his students went wild with joy and excitement when they saw Oersted’s magnetic needle spin round as the circuit was opened or closed. There was good reason for celebration. Oersted had slaved for this success for thirteen years, and it stimulated philosophical investigation to the highest degree. When Faraday, in 1831, made a wire conveying a current revolve around the poles of a magnet, he also celebrated his discovery, rubbing his hands in glee, skipping gaily about the table, making holiday the rest of the day, and winding up with a night off at Astley’s Circus to see the performing horses.
It should be noted that Oersted did not really invent anything. Apparently he did not care to, preferring “knowledge as his highest aim.” But his splendid discovery was seized upon with avidity by all the scientific men of the world. Inventions and other discoveries came thick and fast. As Faraday said, Oersted had “opened the gates of a domain in science, dark till then, and filled it with a flood of light.” This was indeed an achievement for one who at twelve years of age had been an errand boy in a little apothecary’s shop on a small island in the Baltic Sea.
Within a few months, that metaphysical genius, Ampere, had seized upon the inner meaning of the work done at Copenhagen; and between 1820 and 1828 he founded the great workaday science of electrodynamics, by laying down its laws and predicting some of their applications. It is only right that the very unit of electric current should be named after him; for Ampere soon proved that all the phenomena of magnets, action and reaction, pull and push, revolution and polarity, could be repeated with coils of wire through which an electric current was passing—and all the more emphatically if iron was put within the coils. He also showed that currents themselves behaved like magnets, and indeed were magnets.
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Arago, another great French philosopher, in 1820, had invented electromagnets. He discovered that if he wrapped a live wire around a small bunch of iron wires, the wires became magnets, and stayed magnets as long as current flowed in the wire. Davy, to whose great work we are soon coming, also discovered independently the power of the electric current to magnetize iron and steel, and so helped set the stage at the Royal Institution in London for the magnificent performances of his pupil and successor, Faraday.
Before leaving behind Ampere in this swift advance, it may well be noted that, like Thales and Franklin, he also had strong political democratic tendencies. South American patriots visiting France found a warm welcome in Ampere’s pleasant Parisian home, and, next to electromagnetism, nothing stirred him more to red-blooded enthusiasm than discussing the heroic feats of Bolivar and Canaris in creating new republics out of the wrecks of Spanish dominion. Ampere was never ashamed of telling the story of his early years. When only thirteen he read a paper before a certain society in which he solemnly informed the learned members how they could square the circle!
ARC-LIGHTS AND DYNAMOS
About this time the Royal Institution in London, founded by an American in 1800, became the home and work place of two very notable men. Its creator, Count Rumford, was a plain Massachusetts Yankee, Benjamin Thompson, but the fortunes of the War of Independence carried him to Europe, where his genius and ability soon made their mark. The ruler of Bavaria engaged him to manage the royal arsenals. Being a real philosopher, he took the opportunity, while boring a cannon, to prove that heat could be produced by mechanical power. He also taught the Bavarians many arts of peace, and was soon made a count of the Holy Roman Empire. Going back to England, where he had also been created a knight, he secured the charter for the Royal Institution, and chose a clever young Cornishman, Humphry Davy, as lecturer and director of the laboratory.
Davy, whose widowed mother was a poor milliner, became apprenticed to an apothecary-surgeon, and taking up chemistry as a study, soon discovered that the properties of pure nitrous oxide, “laughing-gas,” were respirable and had the power to lessen physical pain, the beginning of modern ansthetics. Electricity also interested him, and his originality justified Rumford’s selection of him as a Royal Institution lecturer. In electrical annals, Davy stands out distinctly in the white glory of his own arc-light, with which his name is associated, and he was one of the most distinguished precursors of the electrical engineer¬¬s of to-day.
Passing the current from a powerful battery which had no fewer than 2,000 plates dipped in acid solution, he secured intensely brilliant illumination from the consumption of two sticks of charcoal. This was in 1808. He called it an “arc” light because the little blue-silvery bow of light formed an “arch” as it wavered between the glowing pieces of carbon rod. With his giant battery, Davy was also able to isolate metallic potassium and sodium; and although France and England were at war, the French Academy magnanimously recommended Davy as the first recipient of the gold medal promised by the vigilant Napoleon for the “best experiment that should be made in each year on the galvanic fluid.” But the world owed him another gold medal for discovering and befriending no less a genius than Michael Faraday, the Columbus of electromagnetic induction.
|Sir Humphrey Davy demonstrates his arc light. Batteries were in the basement.|
Born of humble parents in a remote suburb of London, Faraday had practically no school education. The facts of his early life and how he attended Sir Humphry Davy’s lectures in natural philosophy is told in the chapter on “Radio Communication.” To young Faraday, those clever lectures by Davy had far more fascination than his work in a bookbindery. Faraday’s initial scientific task was the unpleasant one of extracting sugar from beet-roots; and it was succeeded by something even more disagreeable, the manufacture of stinking bisuiphide of carbon. Even that did not discourage him, nor the fact that, when he went abroad with Sir Humphry Davy in 1815, Lady Davy, socially ambitious, refused to dine at the same table with one whom she regarded as the equal of her husband’s valet.
On Christmas Day, 1821, the young wife of the laboratory assistant was invited by her husband to leave the simple domestic part of the stern old Institution where they kept house, and share his delight over a wonderful new experiment. All she saw was a small vase nearly filled with mercury, into which a tiny copper wire dipped. On the mercury floated a little bar magnet, held by a thread to the bottom of the vessel. Now, the wire was in circuit with a “voltaic” battery, and every time the circuit was closed to the mercury, that floating bar, like a chip in a swirl of tide, revolved around the wire. No simpler way could be devised of producing a continuous regular mechanical motion from the action of an electric current.
Faraday always stripped his demonstrations down to the barest elements. Ten years later, before the Royal Society, in 1831, Faraday described his “new electrical machine,” first of many millions that since have embodied the same vital, cardinal idea. His “dynamo” consisted essentially of a disk of copper, twelve inches across, mounted to rotate between the poles of a big permanent magnet. Two collecting brushes, one resting on the axis hub of the wheel and the other on its rim, carried off the current generated as the revolving disk cut through the unseen “lines of magnetic force” of the permanent magnet. Thus was mechanical motion converted into electrical energy; and then by successive stages Faraday, in 1831 and 1832, developed the phenomena of electromagnetic induction, the basis of all our modern dynamo-electric machinery, generators, and motors.
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Moreover, he showed that his “induced” current had all the earmarks of the “voltaic” battery current, and then by an ever-memorable series of experiments he went on to prove that all the electricities are the same: static, dynamo, magneto, voltaic, thermo, animal, etc.—just as all men belong to the human family. Other important discoveries followed, for which there is no room here. Faraday lived a life worthy of one of the world’s greatest scientists. Bence Jones, in his Life and Letters of Faraday, wrote: “His was a lifelong strife to seek and say that which he thought was true; and to do that which he thought was kind.” Long before he died, the world had begun to reap wonderful harvests in his “fields of magnetic force” and from all the great electromagnetic arts that are now “human nature’s daily food.”
William Sturgeon, in England, shared with Arago, in France, the credit of making the first electromagnets. Joseph Henry, in America, shared with Faraday the credit of the first demonstrations of the new principles of induction, magnetic repulsion and attraction. Then, in 1832, came the vanguard of inventors, headed perhaps by H. Pixii, a Frenchman, who began with the invention of magnetos with coils of wire spun around in front of permanent magnets, and later produced “dynamos” in which, instead of permanent magnets, they employed electromagnets, using some of the “self-exciting” current from the machine itself. This was a great stride forward, and, in i86o, Doctor Antonio Pacinotti devised the first dynamo to give “continuous” current, all in one direction, or of one sign, + or -, in place of the “alternating” current which reversed itself incessantly, as in the machines of Varley, Wheatstone, and Siemens.
Next came the famous Belgian, Z. T. Gramme, who in Paris, 1870—72, produced the first practical generator yielding absolutely continuous or direct current. Adopting the soft iron ring of Pacinotti, the Italian professor of vine culture, this master mechanic wrapped around it consecutive lengths of insulated wire, thus forming a number of short, distinct coils, whose ends were brought out to a commutator. Like a series of pipes all leading out one way, each coil as it passed in front of the magnets squirted out its little discharge of current through the commutator ring of copper strips, and that current, of positive sign, could be used for all the innumerable purposes to which continuous or “direct” current is now applied.
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|EVOLUTION OF THE ELECTROMAGNET. (left) Saxton, 1833; Two coils of wire rotate in front of the poles of a steel magnet. The induced current is conducted to the line by a brush or collector. (right) Wheatstone, 1845; In order to obtain more powerful magnets, Wheatstone used electromagnets which were excited by galvanic energy.|
|(left) Wilde, 1861; In order to obtain more powerful electromagnetic effects without the aid of a galvanic current, Wilde used a small auxiliary machine and steel magnets to generate energy for the electromagnets of the main machine. (right) Werner von Siemens, 1866; Von Siemens used the residual magnetism of an electromagnet to induce a feeble current in the armature. This induced current augmented the magnetism of the electromagnet and was itself augmented until the electromagnet was completely saturated.|
|THE GENERATION OF ELECTRICITY BY MOVING WIRES NEAR MAGNETS. (left) In 1831 Michael Faraday discovered that an electric current can be induced in the iron core of a wire coil when a steel magnet was moved toward and from the coil. (right) In the same year, Faraday discovered that electric currents can also be induced in a coil when a near-by coil is electrified or de-electrified. These induced currents were most powerful when both coils had a common ring-shaped iron core.|
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|Historic magneto-electric machines. (left) Pixii, 1832; The coils A, provided with an iron core, rotate in front of the steel magnet B. The electric current induced in the coils by the alternations of magnetic effect in the iron core is collected by the brushes a and b. (right) Wheatstone-Cooke, 1845; The coils A, rotate with their iron core in front of the electromagnet B. The electromagnet B consists of an iron core wound with wire through which flows the electric current obtained from a galvanic element. Thus the iron core is magnetized. The magnetic effect is greater and hence a more powerful current is obtained.|
|REPLICA OF PACINOTTI’S DYNAMO OF 1860. Courtesy of Deutsches Museum.|
|ORIGINAL RING-ARMATURE DYNAMO OF GRAMME (1870). Courtesy of Deutsches Museum.|
|EDISON DYNAMO OF 1883. Courtesy General Electric Company.|
HOW THE ELECTRIC MOTOR WAS ACCIDENTALLY INVENTED
Up to the time of Gramme, people had built electric motors to be operated by current from batteries; then machines to generate current, first for electric lighting and then for electroplating with copper or silver. It was a case of putting the cart before the horse. The dynamo should have come first. But at an industrial exhibition in Vienna, 1873, a number of Gramme dynamos were being set up as exhibits. In making the electrical connections to one of these machines, not yet belted to the shaft of the driving steam-engine, a careless workman by mistake attached to its binding posts the ends of two wires already connected to another dynamo actually in operation. It was the sort of mistake that often happens in an electrical plant, when “hooking up” the machinery.
To the intense astonishment of everybody looking on, the armature of the second machine at once began to revolve with great rapidity. When the attention of Gramme was directed to this highly novel phenomenon, he saw that the second machine was functioning as a motor, with current from the first, and that what took place was an actual transfer of mechanical energy through the agency of electricity. With that remarkable incident began the period of the great modern use of the electric motor for power and domestic purposes, and the development of the art of electric-power transmission, which, in turn, led to the vast water-power utilization of to-day.
Separate chapters in this volume deal with the arts and inventions in electric lighting, electric traction, and telegraphy and telephony, all of which depend for their current supply upon current taken directly from dynamos or from storage batteries whose chemical reactions enable them to deliver the “stored” energy when it is needed, and when the dynamo is out of operation. We shall confine ourselves here to a brief note of some of the other fields of electrical application developed since the days of Pacinotti and Gramme, and mention a few of the “star performers,” to whom a leading share in such utilization must be credited.
APPLICATIONS OF ELECTRICITY
With the invention of the dynamo or generator, came the possibility of electric illumination. How the arc was developed by Brush and the incandescent lamp by Edison is told in the chapter “From Rushlight to Incandescent Lamp.” Both Brush and Edison saw that the dynamo would have to be vastly improved if houses were to be lit by electricity. To Edison belongs the credit of having devised the modern system of generating current in a central station, and supplying it to houses by wires fed from mains. Lamps, dynamos, fuses, switches, all the paraphernalia with which we are now so familiar are his creations—the work of the early eighties.
|THE FIRST CENTRAL STATION. Built by Edison and the nucleus of the present Edison Company. It was opened for operation in 1882. This picture is made from a contemporary print in the Scientific American.|
Edison had barely got his incandescent-lighting system introduced, Brush had not yet finished refining his famous arc-lighting system, and Sprague was at the beginning of his electric-motor development, when the outward urge of all this expansion necessitated some device that would enable central-station plants and electric-trolley railroads to cover larger areas of service from the one source of current supply. It was found in the “transformer” and the alternating current, to which George Westinghouse, inventor of the air-brake, devoted nearly all of his life after 1884.
To understand the transformer, we must go back to Faraday’s discovery, made in 1831, when he wound two coils of wire on a soft ring of iron. When he shot current through one coil he saw by the galvanometer needle in the circuit of the other, that “induced” current was flowing in it also. That is about all we do with the modern transformer, which in its various forms is simply Faraday’s induction-coil.
About 1884, an erratic Frenchman named Gaulard, backed by a sporty Englishman, Gibbs, showed with a crude “secondary generator,” or transformer, that current could be sent miles and miles. The device was like a spring-board or a catapult. Low-pressure current could be put through it in large volume, and, by induction from one coil to the other, could be raised in voltage for long-distance transmission over a very small wire. Conversely, if the alternating current thus raised in pressure was to be used at low pressure, it could be put through a “step-down” transformer at the consumption end of the line, by being received by a fine wire coil, and lowered in pressure and increased in volume by the big wire coil alongside it.
A very brilliant young engineer from the Berkshire Hills of Massachusetts, William Stanley, Jr., took hold of this crude appliance and soon worked out the transformers that were to be the prototypes and forerunners of all those in use in America to-day. Erecting a little laboratory workshop in his native Great Barrington, he gave that town the honor of being the first to illustrate the momentous new departure in electric light and power. The first large alternating-current station was installed by Westinghouse, using the Stanley transformers, in Buffalo, New York, the same year, 1886.
|(Left) THOMAS ALVA EDISON. Edison was the first to supply electricity commerciaily. To him is due the whole modern system of generating current in a central station and distributing it to homes and factories. (Right) WILLIAM STANLEY, INVENTOR OF THE MODERN TRANSFORMER. Courtesy General Electric Company.|
All this early alternating-current work was done with what is called “single-phase” alternating current. Few such generators are made to-day. The first alternating dynamos were “single phase,” so were the first transformers, and their chief virtue was this ability to annihilate distance, although they had many drawbacks. Away on the Serbian borderland of Eastern Europe was born, in 1857, a genius, Nikola Tesla, son of a clergy man in the Greek Church. The Serbians have had little time to give to invention; their task has been the guarding of the Balkan Mountains, the preservation of their little country; and in their language there are a hundred words for knife to one for bread.
As a young student at Graz, Austria, brooding, imaginative Nikola Tesla saw and ran a Gramme dynamo, and with quick intuition he decided that the commutator and brushes were not necessary. Forthwith, he began a career that soon brought him to America, there to invent what is now worldwide in name and application, namely the “polyphase” system; two-phase or three, the latter perhaps predominating to-day.
The first power transmission of Niagara energy began with the Tesla two-phase apparatus built by Westinghouse. Tesla went on to develop other ideas and inventions employing high frequency currents, and thirty years ago he began to demonstrate the wireless transmission of signals and power, becoming the pioneer of all the “broadcasting” now so familiar and fascinating. He also showed many incandescent-lighting effects in lamps without filaments and unconnected to any circuit, and took the first photograph ever secured by fluorescence and phosphorescence—the light of the firefly. At the time of writing, this temperamental genius was still hard at it in the very centre of the “wireless” stage.
|Multi-phase generators at Niagara Falls were a Tesla/Westinghouse cooperative project.|
Of a different type is Doctor Elihu Thomson, who spent all his vastly productive life in America, to which he was brought when only a few years old by his skilful father, a north of England machinist. Thomson’s development of “repulsion phenomena” became the basis of several useful arts, but he might prefer for special mention his creation of the great modern industry of electric welding. Lecturing at the Franklin Institute in Philadelphia, he noted that in one of his experiments the wires of a Ruhmkorff spark-coil had been welded by the instantaneous discharge of a heavy current. With the swift vision of genius, he glimpsed at once the possibilities of electric welding. In 1885, he worked the whole process out, and made the first electric welds that finally became the basis of the enormous extension in welding now seen everywhere in the most varied of arts, from wire manufacture up to the making of hulls of battleships and ocean liners.
A similar new art has grown up out of electrodynamics in the use of the electric furnace. About 1877, that great German pioneer, Siemens, conceived the idea that it should be possible to melt steel commercially by means of the electric arc. He took a crucible, bored holes in the sides, stuck electrodes through the holes, started an arc, and melted steel by radiation. Since then a vast variety of such furnaces have come into use, “not because the electricity plays any peculiar part in the process, but simply because they furnish a convenient means of obtaining very high temperatures which can be easily controlled”; temperatures up to 6,000 degrees Fahrenheit.
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|TWENTY-TON HEROULT ELECTRIC FURNACE. Siemens conceived the idea of melting steel commercially by means of the electric arc. The Frenchman Héroult did much to make this idea practical. This Héroult furnace is used by the Carnegie Steel Company. The annual production of electrosteel throughout the world is now 1,500,000 tons. Courtesy General Electric Company.|
A French chemist, Moissan, specially distinguished himself by work in this field, dealing with refractory substances. In 1893, he actually produced diamonds from common graphite. True, they can barely be seen, unless you look at them under the microscope, but some day artificial diamonds may upset the market for precious stones and compete with nature’s output from the mines of South Africa.
Meantime, the electric furnace is invading the whole field of metallurgy. At the beginning of 1920 no fewer than 900 electric steel-making furnaces were in use throughout the world, with an annual production of I,500,000 tons. But there are also very many electric furnaces for the non-iron metals, such as brass, aluminum, and copper.
In 1881, chancing to hear a remark of a famous gem expert on the value of abrasives, a young American, E. G. Acheson, born in Washington, Pennsylvania, and then only twenty-five years old, set to work along original lines. To him is due the world’s most widely used artificial abrasive, carborundum. He was only sixteen years old when he started work in his father’s blast-furnaces; then, in turn, he became a surveyor’s chainman, a railroad ticket clerk, a worker in the iron mines, and eventually a draftsman for Edison. Under that great inventor’s supervision, Acheson helped in the early perfection and introduction in America and Europe of the incandescent-lighting system; he finally became an inventor on his own account.
In 1891, with an ordinary solder melting-pot for a furnace, Acheson, experimenting with high temperatures in the hope of producing artificial diamonds, and using sand and ground coke for the charge, accidentally obtained “carborundum,” a silicate of carbon. It was a positively new substance and an important abrasive. To-day, with the help of electrical energy from Niagara, millions of pounds of this compound are produced annually.
Acheson continued his experiments in an incandescent furnace. One day, after overheating the furnaces, in which, like Moissan, he actually produced minute diamonds, Acheson noted a black substance with a greasy surface. It was graphite. Once more, a whole realm of electric metallurgy and chemistry was opened up. Acheson next proceeded to divide this artificial graphite by “deflocculation,” thereby grinding it up about as far as mechanic processes can go, and discovered a new series of lubricants. Kindred researches have carried Acheson far into the electrical manufacture of clays, fine crucibles, and into several other arts.
The chapter, thus far, has dealt but slightly with electrochemistry, or “electrolysis,” which includes the arts of electroplating and the refining of copper—most American copper now being thus heated to secure very high purity. A large part of the electric current generated at Niagara Falls is thus employed in making bleaching powders. In much the same way a very persevering American, T. L. Willson, made calcium carbide, from which is obtained the illuminating gas called acetylene, an account of which discovery will be found in the chapter, — “From Rushlight to Incandescent Lamp.” Most notable of all has been the extraction, from very ordinary earthy substances, of the metal aluminum, so vital to many industries, such as aviation. Before American inventors, such as the Cowles brothers and Charles M. Hall, put their wits to work in 1886, aluminum sold at four dollars a pound and was hard to get; but after they and Héroult, the Frenchman, had developed their processes and “baths,” it could be bought in ingots like pig iron at only twenty cents a pound.
This work brings us into another great field of modern electrical development, that of electric heating and cooking, particularly for domestic purposes. Benjamin Franklin, in 1747, proposed an “Electrical Dinner” when a turkey was to be killed by electric shock, and roasted by the electric jack before a fire kindled by the electric bottle. But it was more than 150 years later before the prophetic fancy passed into a commonplace actuality.
In 1891, an Englishman, H. J. Downing, gave an exhibit of his “radiant heat” electric-cooking appliances at the Sydenham Crystal Palace. Before that nothing really worth while in electric cooking had been invented. Four years later, a young American, W. S. Hadway, devised a little plant for cooking, which instantly proved practicable. The equipment consisted of an oven, small portable stoves, “spider,” plate-warmer, coffee-pot, and teakettle. In 1896-97, Hadway installed an electric range in the Fifth Avenue mansion of Andrew Carnegie, New York City.
|ELECTRIC OVEN USED FOR BAKING DOLLS’ HEADS. Courtesy of General Electric Company.|
Within a few years, many inventors and manufacturers were in the field, and in 1920 the production of electric ranges in the United States exceeded 40,000, from some eighteen producers. But the electric ranges are only one of a group of such electrical appliances now made and used in America. There are more than fifty varieties on the market, in the purchase of which for use in the home, the public spent no less than $175,000,000 in 1919. Associated with all these articles that lessen enormously the burden of housekeeping and the need for domestic servants, is another ingenious group of appliances such as electric vacuum cleaners and washing-machines, all helped in adoption by the fact that, whereas the cost of nearly everything has gone up enormously in the last ten years, the price of electric current has steadily gone down.
Millions of these ingenious and useful devices due to American inventors are now produced yearly, but probably none more numerously than the universal fan motor, by which our civilization furnishes itself with cooling breezes in summer and heated currents of air in winter. The punkah coolies of India and fan-bearers of all the Eastern world, are outmatched by this little American device. In 1904, the Franklin Institute awarded to Doctor Schuyler S. Wheeler its John Scott gold medal for his invention of an electric fan, reduced to practice in 1886. Wheeler, who had to struggle very hard to complete his education at Columbia University, secured a position with the first Edison electric light company, started in New York in 1882.
While working, he and his great chief, Edison, slept in the famous Pearl Street station, on cots set up right alongside the steam-engines, so that they did not leave the plant for several days and nights. Later Wheeler became a maker of small electric motors, and it occurred to him that by increasing the “shaft height” and by turning upside down the type of motor made to run sewing-machines, a little wind-blowing propeller could be hitched on—and there was the fan motor! Useful fan motors are now countless, and Wheeler proceeded to “fabricate” millions of horse-power in industrial motors, equipping notably some of the largest American steel works for “electric drive.”
|ELECTRIC AUGER DRILLING HOLES IN A PIANO FRAME. Courtesy Van Dorn L Tool Company.|
|MOTOR-DRIVEN MILK-AND-CREAM SEPARATOR. Courtesy Society for Electric Development.|
It is now a rare day that does not bring news of yet another electrical invention or application. No sphere of life is left untouched. “Behold, I make all things new” is the inspired Scriptural phrase that might be applied to this renovating influence. A late discovery is the electrolytic waterproofing of textile fabrics, by the process of A. 0. Tate, a brilliant young Canadian engineer, once private secretary to Edison, for whom, as an expert telegrapher, he did original work.
In developing storage-batteries and electric filters of his own, Tate came to the conclusion that by means of electric current he could impregnate fibrous materials with a water-repelling substance. Thus he manufactured a fabric not only water-proof, but mildew-proof, and of a higher grade of quality. The process was first installed in Montreal, Canada, in 1916, and operated by an Imperial Commission. In July, 1920, the celebrated Cranston Print Works, Rhode Island, were equipped for an output of 30,000,000 yards per annum of electrolytically waterproofed and electrically “converted” fabrics. Cottons and woollens alike gain by the process, as do most of the clothes we wear; duck and canvas for sails and tents are also now largely treated in this way; wall-papers that can be washed with a hose are another group involved in changes so novel and comprehensive that the mere term “waterproofing” is inadequate to describe them.
ELECTRICITY AND WATER-POWER
It is remarkable that books on invention and the encyclopedias have so little to say about water-power or wind-power. The reason for this is probably that no really first-class inventor has ever associated his name with modern adaptations of the very ancient devices that depend on breezes or falling water. There is, of course, a large amount of literature on hydraulics, but the student will hunt in vain for enough books on wind-power to fill a five-foot shelf, even if he include treatises on sails for ships.
It is not likely that the march of mankind in the path of civilization was governed in any way by the local prevalence of steady currents of air to drive windmills; but it is known that, next to having access to water for drinking, our forefathers valued running water for its ability to furnish power for their primitive industries and later on to operate small factories. Even then, they depended just as largely on animal-power or the muscular effort of human beings. To this day, in old Asia, teams of men are still employed to do the sort of work which in America is more easily and smoothly accomplished by the electric motor.
For present purposes, wind-power may be forgotten; but to the Hollander it is very necessary, practical, and useful. There are, however, very few dynamo-plants driven by wind-power. The wonder is that more do not exist, especially where coal costs twenty dollars or more a ton, where water-power is scarce, and where currents of air like “trade-winds” are almost as dependable as the rising sun or the turn of the tide. Some day, also, electricity may be generated more or less directly from the sun’s heat, which after all, is what moves the air and the water.
The history of the development of water-power and its application to general use has been concomitant with that of electricity. Flowing water can spin a wheel with a breast or frontal attack; it can drop on the wheel from above; or drive it with an underflow. The principle, the same in each case, is plainly illustrated by our domesticated white mouse and squirrel when they tread their tiny paddle-wheels and merry-go-rounds in a cage. In ancient times water turned a mill-wheel, thereby revolving clumsy millstones, between which were ground wheat and other necessities for human consumption and maintenance. But many years went by before it was realized that a wheel steadily turned by water-power provided a continual source of energy that could be used in several different ways.
The water-turbine, upon which our great, modern hydroelectric plants depend, had its beginning in 1827. In that year, Benoit Fourneyron, a young Frenchman of twenty-five, winning a prize offered in his native country, gave the world the modern turbine water-wheel, in which water is received not outside but inside the wheel it drives. There have been subsequent additions to his invention, many exceedingly valuable improvements coming from such Americans as Howd, Francis, Morris, and others; but all have been as edifices built upon the foundation of Fourneyron’s original idea.
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|SECTION THROUGH THE FOURNEYRON WATER-TURBINE OF 1834. Foruneyron’s water-turbine in its earlier forms had a vertical cylindrical chamber with a side inlet for the water and a central pipe below, through which the water passed to an annular outlet at the base of the pipe. This outlet was fitted with guide-blades which directed the water tangentially as it escaped. Surrounding this passage was a driving-wheel, keyed to a vertical shaft and provided with vanes between which the water flowed as it passed from the inner to the outer circumference, where it was finally discharged. Courtesy of Deutsckes Museum, Munich.|
Once the way was discovered, the United States with her natural aptitude for invention and development, lost little time in making good use of water-power. Europe, perhaps with lesser facilities for practice, remained somewhat behind. Not many years ago on the River Adige, in Italy, the writer witnessed barges out in mid-stream getting their feeble power from the torrent that came down from the remote mountains. It is now easier to lead the torrent to the turbine than the turbine to the torrent. Man’s ingenuity has made water-power act as his slave. He has forced water to fall into buckets around the rim of a wheel, or, as in our modern turbine of various types, shot it through the middle of the wheel.
The famous Pelton water-wheel, invented and developed in 1884, proves what can be accomplished with cups or buckets around the periphery of a wheel. Pelton, a plain Ohio carpenter, ventured out to California during the gold-fever days of the “Forty-niners.” There he saw more wealth in water-power than could ever be extracted from the placers and the rocks. His water-wheel plant, draining the waste surface waters at the Chollar mine on the Comstock Lode in the Sierra Nevadas, was hitched to a Brush 130-horse-power dynamo.
After having first driven another electric generator on the surface, the buckets on the wheel were forced into whirlwind speed by water falling into them from a height of over 1,600 feet. A jet of water from the directing nozzle smashed into the twin cups at a speed of many miles an hour. With the current thus obtained, six electric motors, each of eighty horse-power, were operated in the Nevada stamp-mill more than a mile away. No more convincing proof could be desired of “high-head” hydroelectric power. The Comstock Lode has long since lost its value and glory; but the wealth of its water-power will probably never be’ exhausted.
One of the advantages in using water-power is that it is power saved, and not wasted, as it is with coal. By skill and good luck, the electric lamp, motor, or cook-stove may get six to ten per cent of the energy from burned coal to run the steam dynamo; ninety per cent of the whole energy is irrevocably lost. With hydroelectric power, at least six to ten per cent is saved of what was previously a hundred per cent loss in available power; all the coal is saved, because the water is still on hand. This great economy of power was demonstrated by the Pelton water-wheel.
Water-turbines have rendered possible all that is now going on in electric-power transmission. The hydroelectric utilization of Niagara for transmission of current to long distances began in 1895 with units of 5,000 horse-power. To-day there are six electric power-producing companies at the Falls, and the latest plant, at this date has in operation three turbine units of 37,500 horse-power each. But while such power at Niagara is transmitted at 6o,ooo volts pressure, voltages twice as high are in use elsewhere, and 300,000 volts is a potential talked of as glibly and confidently as was 10,000 twenty-five years ago.
|TWENTY-FIVE-TON WATER-WHEEL. Pelton wheel for the 30,000 horse-power units built for Great Western Power Company’s Caribou plant, California. Courtesy Allis-Chalmers Company.|
The total possible water-power of the world is computed at about 450,000,000 horse-power at low water. For millions of years this vast power, greater than that possessed and dreamed of by kings and dynasties, has flowed freely, placidly, and uninterruptedly to the seas.
The United States mines annually about 700,000,000 tons of coal, and the supply must sooner or later give out. Water-power, if developed to the highest degree, would furnish more energy yearly than a billion tons of coal, although it can never supply all the electrical energy needed. Hydroelectric development alone has now made it feasible and profitable to use nearly all of this tremendous power in the years to come. Water-power electrifies the great railway systems of the world; it lights San Francisco and Los Angeles with current from the snowy slopes of the Sierras, about 300 miles away. In fact, hydroelectrical energy will help to keep our lamps and wheels going until physicists learn to break up atoms and thus open up new stores of pristine power from “founts that ne’er can run dry.”
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|PART OF NIAGARA’S HARNESS. Section through one of the 55,000 horse-power units for the Niagara development of the Hydro-Electric Power Commission of Ontario. Courtesy William Cramp Skip and Engine Building Company.|
|MODERN HYDROELECTRIC PLANT. The dam which backs up the water is clearly visible; so are the penstocks and the powerplant itself, to which water is supplied by the penstocks. Courtesy General Electric Company.|