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Nature's Miracles Volume 3: Electricity and Magnetism

<h2>CHAPTER II.</h2> <h3>HISTORY OF ELECTRICAL SCIENCE.</h3> Electricity as a well-developed science is not old. Those of us who have lived fifty years have seen nearly all its development so far as it has been applied to useful purposes, and those who have lived over twenty-five years have seen the major portion of its development. Thales of Miletus, 600 B.C., discovered, or at least described, the properties of amber when rubbed, showing that it had the power to attract and repel light substances, such as straws, dry leaves, etc. And from the Greek word for amber—elektron—came the name electricity, denoting this peculiar property. Theophrastus and Pliny made the same observations; the former about 321 B.C., and the latter about 70 A.D. It is also said that the ancients had observed the effects of animal electricity, such as that of the fish called the torpedo. Pliny and Aristotle both speak of its power to paralyze the feet of men and animals, and to first benumb the fish which it then preyed upon. It is also recorded that a freed-man of Tiberius was cured of the gout by the shocks of the torpedo. It is further recorded that Wolimer, the King of the Goths, was able to emit sparks from his body. Coming down to more modern times—A.D. 1600—we find Dr. Gilbert, an Englishman, taking up the investigation of the electrical properties of various substances when submitted to friction, and formulating them in the order of their importance. In these experiments we have the beginnings of what has since developed into a great science. He made the discovery that when the air was dry he could soon electrify the substances rubbed, but when it was damp it took much longer and sometimes he failed altogether. In 1705 Francis Hawksbee, an experimental philosopher, discovered that mercury could be rendered luminous by agitating it in an exhausted receiver. (It is a question whether this phenomenon should not be classed with that of phosphorescence rather than electricity.) The number of investigators was so great that all of them cannot be mentioned. It often happens that those who do really most for a science are never known to fame. A number of people will make small contributions till the structure has by degrees assumed large proportions, when finally some one comes along and puts a gilded dome on it and the whole structure takes his name. This is eminently true of many of the more important developments in the science and applications of electricity during the last twenty-five or thirty years. Following Hawksbee may be mentioned Stephen Gray, Sir Isaac Newton, Dr. Wall, M. Dupay and others. Dupay discovered the two conditions of electrical excitation known now as positive and negative conditions. In 1745 the Leyden jar was invented. It takes its name from the city of Leyden, where its use was first discovered. It is a glass jar, coated inside and out with tin-foil. The inside coating is connected with a brass knob at the top, through which it can be charged with electricity. The inner and outer coatings must not be continuous but insulated from each other. The author's name is not known, but it is said that three different persons invented it independently, to wit, a monk by the name of Kleist, a man by the name of Cuneus, and Professor Muschenbroeck of Leyden. This was an important invention, as it was the forerunner of our own Franklin's discoveries and a necessary part of his outfit with which he established the identity of lightning and electricity. Every American schoolboy has heard, from Fourth of July orations, how "Franklin caught the forked lightning from the clouds and tamed it and made it subservient to the will of man." How my boyish soul used to be stirred to its depths by this oratorical display of electrical fireworks! Franklin had long entertained the idea that the lightning of the clouds was identical with what is called frictional electricity, and he waited long for a church spire to be erected in his adopted home, the Quaker City, in order that he might make the test and settle the question. But the Quakers did not believe in spires, and Franklin's patience had a limit. Franklin had the theory that most investigators had at that time, that electricity was a fluid and that certain substances had the power to hold it. There were two theories prevalent in those days—both fluid theories. One theory was that there were two fluids, a positive and a negative. Franklin held to the theory of a single fluid, and that the phenomenon of electricity was present only when the balance or natural amount of electricity was disturbed. According to this theory, a body charged with positive electricity had an excessive amount, and, of course, some other body somewhere else had less than nature had allotted to it; hence it was charged with negative electricity. A Leyden jar, for instance, having one of its coatings (say the inside) charged with positive or + electricity, the other coating will be charged with negative or - electricity. The former was only a name for an amount above normal and the latter a name for a shortage or lack of the normal amount. As we have said, Franklin believed in the identity of lightning and electricity, and he waited long for an opportunity to demonstrate his theory. He had the Leyden jar, and now all he needed was to establish some suitable connection between a thunder-cloud and the earth. Previous to 1750 Franklin had written a paper in which he showed the likeness between the lightning spark and that of frictional electricity. He showed that both sparks move in crooked lines—as we see it in a storm-cloud, that both strike the highest or nearest points, that both inflame combustibles, fuse metals, render needles magnetic and destroy animal life. All this did not definitely establish their identity in the mind of Franklin, and he waited long for an opportunity, and finally, finding that no one presented itself, he did what many men have had to do in other matters; he made one. In the month of June, 1752, tired of waiting for a steeple to be erected, Franklin devised a plan that was much better and probably saved the experiment from failure; for the steeple would probably not have been high enough. He constructed a kite by making a cross of light cedar rods, fastening the four ends to the four corners of a large silk handkerchief. He fixed a loop to tie the kite string to and balanced it with a tail, as boys do nowadays. He fixed a pointed wire to the upper end of one of the cross sticks for a lightning-rod, and then waited for a thunder-storm. When it came, with the help of his boy, he sent up the kite. He tied a loop of silk ribbon on the end of the string next his hand—as silk was known to be an insulator or non-conductor—and having tied a key to the string he waited the result, standing within a door to prevent the silk loop from getting wet and thus destroying its insulating qualities. The cloud had nearly passed and he feared his long waited for experiment had failed, when he noticed the loose fibers of the string standing out in every direction, and saw that they were attracted by the approach of his finger. The rain now wet the string and made a better conductor of it. Soon he could draw sparks with his knuckle from the key. He charged a Leyden jar with this electrical current from the thunder-cloud, and performed all the experiments with it that he had done with ordinary electricity, thus establishing the identity of the two and confirming beyond a doubt what he had long before believed was true. In after experiments Franklin found that sometimes the electricity of the clouds was positive and at other times negative. From this experiment Franklin conceived the idea of erecting lightning-rods to protect buildings, which are used to this day. The news spread all over Europe, not through the medium of electricity, however, but as soon as sailing vessels and stage-coaches could carry it. Many philosophers repeated the experiments and at least one man sacrificed his life through his interest in the new discovery. In 1753 Professor Richman of St. Petersburg erected on his house a metal rod which terminated in a Leyden jar in one of the rooms. On the 31st of May he was attending a meeting of the Academy of Sciences. He heard a roll of thunder and hurried home to watch his apparatus. He and one of the assistants were watching the apparatus when a stroke of lightning came down the rod and leaped to the professor's head. He was standing too near it and was instantly killed. Passing over many names of men who followed in the wake of Franklin we come to the next era-making discovery, namely, that of galvanic electricity. In the year 1790 an incident occurred in the household of one Luigi Galvani, an Italian physician and anatomist, that led to a new and important branch of electrical science. Galvani's wife was preparing some frogs for soup, and having skinned them placed them on a table near a newly charged electric machine. A scalpel was on the table and had been in contact with the machine. She accidentally touched one of the frogs to the point of the scalpel, when, lo! the frog kicked, and the kick of that dead frog changed the whole face of electrical science. She called her husband and he repeated the experiment, and also appropriated the discovery as well, and he has had the credit of it ever since, when really his wife made the discovery. Galvani supposed it to be animal electricity and clung to that theory the rest of his life, making many experiments and publishing their results; but the discovery led others to solve the problem. Alessandro Volta, a professor of natural philosophy at Pavia, Italy, was, it must be said, the founder of the science of galvanic or voltaic electricity. Stimulated by the discovery of Galvani he attributed the action of the frog's muscles, not to animal electricity, but to some chemical action between the metals that touched it. To prove his theory, he constructed a pile made of alternate layers of zinc, copper, and a cloth or pasteboard saturated in some saline solution. By repeating these trios—copper, zinc, and the saturated cloth—he attained a pile that would give a powerful shock. It is called the Voltaic Pile. I have a clear idea of the construction of this form of pile, founded on experience. It was my habit when a boy to make everything that I found described, if it were possible. The bottom of my mother's wash-boiler was copper, and just the thing to make the square plates of copper to match the zinc ones, made from another piece of domestic furniture used under the stove. I shocked my mother twice—first with the voltaic pile that I had constructed, and again when she found out where the metal plates came from. The sequel to all this was—but why dwell upon a painful subject! Galvanism and voltaic electricity are the same. Volta was the first to construct what is termed the galvanic battery. The unit of electrical pressure or electromotive force is called the volt, and takes its name from Volta, the great founder of the science of galvanic or voltaic electricity. From this pile constructed by Volta innumerable forms of batteries have been devised. The evolution of the galvanic battery in all its forms, from Volta to the present day, would fill a large volume if all were described. The discoveries of Michael Faraday (1791-1867), the distinguished English chemist and physicist, led to another phase of the science that has revolutionized modern life. Faraday made an experiment that contains the germ of all forms of the modern dynamo, which is a machine of comparatively recent development. He found that by winding a piece of insulated wire around a piece of soft iron and bringing the two ends (of the wire) very close together, and then placing the iron across the poles of a permanent magnet and suddenly jerking it away, a spark would pass between the two ends of the wire that was wound around the piece of soft iron. Here was an incipient dynamo-electric machine—the germ of that which plays such an important part in our modern civilization. Having brought our history down to the present day, it would seem scarcely necessary to recite that which everybody knows. It is well, however, to call a halt once in a while and compare our present conditions of civilization with those of the past. Our world is filled with croakers who are always sighing for the good old days. But we can easily imagine that if they could go back to those days their croaking would be still louder than it is. Before the advent of electricity many things were impossible that are easy now. In the old days the world was very, very large; now, thanks to electricity, it is knocking at the door of every man's house. The lumbering stage-coach that was formerly our limited express—limited to thirty or forty miles a day—has been supplanted by one that covers 1000 miles in the same time, and this high rate of speed is made possible only by the use of the electric telegraph. In the old days all Europe could be involved in a great war and the news of it would be weeks in reaching our shores, but now the firing of the first gun is heard at every fireside the world over, almost before the smoke has cleared away. Our planet is threaded with iron nerves that run over mountains and under seas, whose trembling atoms, thrilled with the electric fire, speak to us daily and hourly of the great throbbing life of the whole civilized world. Electricity has given us a voice that can be heard a thousand miles, and not only heard, but recognized. It has given us a pen that will write our autograph in New York, although we are still in Chicago. It has given us the best light, both from an optical and a sanitary standpoint, that the world has ever seen. The old-fashioned, jogging horse-car has been supplanted by the electric "trolley," and we no longer have our feelings harrowed with pity for the poor old steeds that pulled those lumbering coaches through the streets, with men and women crowded in and hanging on to straps, while everybody trod on every other body's toes. <div class="blockquot"> "In olden times we took a car Drawn by a horse, if going far, And felt that we were blest; Now the conductor takes the fare And puts a broomstick in the air— And lightning does the rest. "In other days, along the street, A glimmering lantern led the feet, When on a midnight stroll; But now we catch, when night is nigh, A piece of lightning from the sky And stick it on a pole. "Time was when one must hold his ear Close to a whispering voice to hear, Like deaf men—nigh and nigher; But now from town to town he talks And puts his nose into a box And whispers through a wire." </div> So jogs the old world along. We sometimes think it is slow, but when we look back a few years and see what has been accomplished it seems to have had a marvelously rapid development. Something like fifty years ago a professor of physics in one of our colleges was giving his class a course in electricity. The electric telegraph was too little known at that time to cut much of a figure in the classroom, so the stock experiments were those made with the frictional electric machine and the Leyden jar. One day the professor had, in one hour's time, taken his class through a course of electricity, and at the end he said: "Gentlemen, you were born too late to witness the development of this great science." I often wonder if the good professor is ever allowed to part the veil that separates us from the great beyond and to look down upon this busy world of ours in which electricity plays such an important part in our every-day life; and if so, what he thinks of that little speech he made to the boys fifty years or more ago. If we make an analysis of the history of the science of electricity we shall see that it has progressed in successive eras, shortening as they approach our time. For a period of 2300 years, from Thales to Franklin, but little or no progress was made beyond the further development of the phenomena of frictional electricity—the most important invention being that of the Leyden jar. From Franklin to Volta was forty-eight years, and from Volta to Faraday about thirty-two years. From this time on the development was very rapid as compared with the old days. Soon after Faraday, Morse, Henry, Wheatstone, and others began experiments that have grown, during fifty or sixty years, into a most colossal system of electric telegraphs, telephones, electric lights and electric railroads. In the latter days marvel has succeeded marvel with such rapid strides that the ink is scarcely dry from the description of one before another crowds itself upon our attention. Where it will all end no one knows, but that it has ended no one believes. The human mind has become so accustomed to these periodic revelations of the marvelous that it must have the stimulus once in a while or it suffers as the toper does when deprived of his cups. The commercial instinct of the news-vender is not slow to see the situation, and if the development is too slow to suit the public demand his fertile brain supplies the lack. So that every few days we hear of some great discovery made by some one it may be unknown to fame. It has served its purpose. The public mind has had its mental toddy and has been saved from a fit of intellectual delirium tremens that it was in danger of from lack of its accustomed stimulus. Having given you a very limited outline of the history of electricity, from ancient times down to the present, we will endeavor now to give you an elementary notion of the science as it stands to-day. To the common mind the science is a blank page. So little is known of it by the ordinary reader, who is fairly intelligent in other matters, that to account for anything that we do not understand it is only necessary to say that it is an electrical phenomenon and he accepts it. Electricity is a synonym for all that we cannot understand. Inasmuch as magnetism is so closely related to electricity in its uses as related to every-day life, we will carry the two subjects along together, as the one will to a large extent help to explain the other. In our next chapter we will look at the history of magnetism. <hr style="width: 65%;" /> <div style="break-after:column;"></div>

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