 The purpose of this little book is to give a general idea of a few of the books I have written. For more information or to volunteer, please visit LibriVox.org, recording by Avae in April 2020. Marvels of Modern Science by Paul Severing. Introduction The purpose of this little book is to give a general idea of a few of the great achievements of our time. Within such a limited space it was impossible to even mention thousands more of the great inventions and triumphs which mark the rushing progress of the world in the present century. Therefore, only those subjects have been treated which appeal with more than passing interest to all. For instance, the flying machine is engaging the attention of the old, the young and the middle-aged and soon the whole world will be on the wing. Radium, the revealer, is opening the door to possibilities almost beyond human conception. Wireless telegraphy is crossing thousands of miles of space with invisible feet and making the nations of the earth as one. It is the same with the other subjects. One and all are of vital human interest and are extremely attractive on account of their importance in the civilization of today. Mighty, sublime, wonderful as have been the achievements of past science as yet we are but on the verge of the continents of discovery. Where is the wizard who can tell what lies in the womb of time? Just as our conceptions of many things have been revolutionized in the past, those which we hold today of the cosmic processes may have to be remodeled in the future. The men of fifty years hence may laugh at the circumscribed knowledge of the present and shake their wise heads in contemplation of what they will term our crudities and which we now call progress. This is ever on the march and what is new today will be old tomorrow. We cannot go back, we must go forward and although we can never reach finality in ought we can improve on the past to enrich the future. If this volume creates an interest and arouses an enthusiasm in the ordinary men and women into whose hands it may come and stimulates them to a study of the great events making for the Enlightenment, progress and elevation of the race it shall have fulfilled its mission and served a purpose for which it was written. End of introduction. CHAPTER I. FLYING MACHINES. EARLY ATTEMPTS AT FLIGHT. THE DERIGIBLE. P. LANGLEY'S EXPERIMENT. THE RIGHT BROTHERS. COUNT ZEPPELIN. RECENT AEROPLANE RECORDS. It is hard to determine when men first essay the attempt to fly. In myth, legend and tradition we find allusions to aerial flight and from the very dawn of authentic history philosophers poets and writers have made allusion to the subject showing that the idea must have early taken root in the restless human heart. ESCALIS EXCLAIMS. O MIGHT I SIT SUBLIME IN AIR WHERE WATERY CLOUDS THE FREEZING SNOWS PREPARE. ARIOSTO IN HIS ORLANDO FURIOSO MAKES AN INGLISH NIGHT WHOM HE NAMES ASTOLFO FLY TO THE BANKS OF THE NILE. Nowadays the authors are trying to make their heroes fly to the North Pole. Some will have it that the ancient world had a civilization much higher than the modern and was more advanced in knowledge. It is claimed that steam engines and electricity were common in Egypt thousands of years ago and that literature, science, art and architecture flourished as never since. Certain it is that the pyramids were, for a long time, the most solid sky scrapers in the world. Perhaps after all our boasted progress is but a case of going back to first principles of history or rather tradition repeating itself. The flying machine may not be as new as we think it is. At any rate the conception of it is old enough. In the thirteenth century Roger Bacon, often called the father of philosophy, maintained that the air could be navigated. He suggested a hollow globe of copper to be filled with ethereal air or liquid fire, but he never tried to put his suggestion into practice. Father Vesan, a missionary at Canton in a letter dated September 5th, 1694, mentions a balloon that ascended on the occasion of the coronation of the Empress Pho King in 1306, but he does not state where he got the information. The balloon is the earliest form of air machine of which we have record. In 1767 a doctor Black of Edinburgh suggested that a thin bladder could be made to ascend if filled with inflammable air, the name then given to hydrogen gas. In 1782 Cavallo succeeded in sending up a soap-bubble filled with such gas. It was in the same year that the Montgolfier brothers of Anonnais, under Lyon in France, conceived the idea of using hot air for lifting things into the air. They got this idea from watching the smoke curling up the chimney from the heat of the fire beneath. In 1783 they constructed the first successful balloon of which we have any description. It was in the form of a round ball, one hundred and ten feet in circumference and, with the frame, weighed three hundred pounds. It was filled with twenty-two thousand cubic feet of vapor. It rose to a height of six thousand feet and proceeded almost seven thousand feet when it gently descended. France went wild over the exhibition. The first to risk their lives in the air were Monsieur Pilatre de Rosé and the Marquis de Arland who ascended over Paris in a hot air balloon in November, 1783. They rose five hundred feet and traveled a distance of five miles in twenty-five minutes. In the following December Monsieur Charles and Robert, also Frenchman, ascended ten thousand feet and traveled twenty-seven miles in two hours. The first balloon ascension in Great Britain was made by an experimenter named Titler in 1784. A few months later Lunardi sailed over London. In 1863 three Englishmen, Green, Mason, and Holland, went from London to Germany, five hundred miles, in eighteen hours. The greatest balloon exhibition up to then, indeed the greatest ever as it has never been surpassed, was given by Glacier and Coxwell, two Englishmen, near Wolverhampton, on September fifth, 1862. They ascended to such an elevation that both lost the power of their limbs, and had not Coxwell open the descending valve with his teeth they would have ascended higher and probably lost their lives in the rarefied atmosphere, for there was no compressed oxygen then, as now, to inhale into their lungs. The last reckoning of which they were capable before Glacier lost consciousness showed an elevation of twenty-nine thousand feet, but it is supposed that they ascended eight thousand feet higher before Coxwell was able to open the descending valve. In 1901 in the city of Berlin, two Germans rose to a height of thirty-five thousand feet, but the two Englishmen of almost fifty years ago are still given credit for the highest ascent. The largest balloon ever sent aloft was the giant of Monsieur Nadar, a Frenchman, which had a capacity of two hundred and fifteen thousand cubic feet, and required for a covering twenty-two thousand yards of silk. It ascended from the Champ de Marre, Paris, in eighteen fifty-three, with fifteen passengers, all of whom came back safely. The longest flight made in a balloon was that by Count de Leval, one thousand one hundred and ninety-three miles, in 1905. A mammoth balloon was built in London by A. E. Godron. In 1908, with three other aeronauts, Godron crossed the crystal palace to the Belgian coast at Ostend, and then drifted over northern Germany, and was finally driven down by a snowstorm at Matécky Derevny in Russia, having traveled one thousand one hundred and seventeen miles in thirty-one and one half hours. The first attempt at constructing a dirigible balloon, or airship, was made by Monsieur Giffard, a Frenchman, in eighteen fifty-two. The bag was spindle-shaped, and one hundred and forty-four feet from point to point. Though it could be steered without drifting, the motor was too weak to propel it. Giffard had many imitations in the spindle-shaped envelope construction, but it was a long time before any good results were obtained. It was not until 1884 that Monsieur Gaston Tissanier constructed a dirigible in any way worthy of the name. It was operated by a motor driven by a bicromate of soda battery. The motor weighed one hundred and twenty-one pounds. The cells held liquid enough to work for two and one half hours, generating one and one-third horsepower. The screw had two arms and was over nine feet in circumference. Tissanier made some successful flights. The first dirigible balloon to return once it started was known as La France. This airship was also constructed in 1884. The designer was Commander Renard of the French Marine Corps, constructed by Captain Krebs of the same service. The length of the envelope was one hundred and seventy-nine feet, its diameter twenty-seven and one-half feet. The screw was in front instead of behind, as in all others previously constructed. The motor, which weighed two hundred and twenty and one-half pounds, was driven by electricity and developed eight and one half horsepower. The propeller was twenty-four feet in diameter and only made forty-six revolutions to the minute. This was the first time electricity was used as a motor force, and mighty possibilities were conceived. In 1901 a young Brazilian, Santos Dumont, made a spectacular flight. Monsieur Deutsch, a Parisian millionaire, offered a prize of twenty thousand dollars for the first dirigible that would fly from the Parc d'Arestat encircle the Eiffel Tower and return to the starting point within thirty minutes, the distance of such flight being about nine miles. Dumont won the prize, though he was some forty seconds over time. The length of his dirigible, on this occasion, was one hundred and eight feet, the diameter nineteen and one-half feet. It had a four-cylinder petroleum motor weighing two hundred and sixteen pounds, which generated twenty horsepower. The screw was thirteen feet in diameter and made three hundred revolutions to the minute. From this time onward great progress was made in the constructing of airships. Government officials and many others turned their attention to the work. Factories were put in operation in several countries of Europe, and by the year 1905 the dirigible had been fairly well established. Zeppelin, Parceval, Le Bodis, Bedouin, and Gross were crowding one another for honours. All had given good results, Zeppelin especially had performed some remarkable feats with his machines. In the construction of the dirigible balloon great care must be taken to build a strong as well as light framework, and to suspend a car from it so that the weight will be equally distributed, and above all so to contrive the gas contained that under no circumstances can it become tilted. There is great danger in the event of tilting that some of the stays suspending the car may snap and the construction fall to pieces in the air. In deciding upon the shape of a dirigible balloon the chief consideration is to secure an end surface which presents the least possible resistance to the air, and also to secure stability and equilibrium. Of course the motor, fuel and propellers are other considerations of vital importance. The first experimenter on the size of wing surface necessary to sustain a man in the air calculated from the proportion of weight and wing surface in birds was Carl Mirvine of Bodden. He calculated that a man weighing two hundred pounds would require one hundred and twenty-eight square feet. In 1781 he made a spindle-shaped apparatus presenting such a surface to the resistance of the air. It was collapsible on the middle, and here the operator was fastened and lay horizontally with his face towards the earth, working the collapsible wings by means of a transverse rod. It was not a success. During the first half of the nineteenth century there were many experiments with wing surfaces, none of which gave any promise. In fact it was not until 1865 that any advance was made, when Francis Wenham showed that the lifting power of a plane of great superficial area could be obtained by dividing the large plane into several parts arranged on tiers. This may be regarded as the germ of the modern aeroplane, the first glimmer of hope to filter through the darkness of experimentation until then. When Wenham's apparatus went against a strong wind it was only lifted up and thrown back. However the idea gave thought to many others years afterwards. In 1885 the brothers Lillienthal in Germany discovered the possibility of driving curved airplanes against the wind. Otto Lillienthal held that it was necessary to begin with saline flight, and first of all that the art of balancing in the air must be learned by practical experiments. He made several flights of the kind now known as gliding. From a height of one hundred feet he glided a distance of seven hundred feet, and found that he could deflect his flight from left to right by moving his legs, which were hanging freely from the seat. He attached a light motor weighing only ninety-six pounds, and generating two-and-a-half horsepower. To sustain the weight he had to increase the size of his planes. Unfortunately this pioneer in modern aviation was killed in an experiment, but he left much data behind which has helped others. This was the first actual flyer which demonstrated the elementary laws governing real flight, and blazed the way for the successful experiments of the present time. His example made the gliding machine a continuous performance until real practical aerial flight was achieved. As far back as 1894 Maxime built a giant aeroplane, but it was too cumbersome to be operated. In America the wonderful work of Professor Langley of the Smithsonian Institution, with his aerodromes, attracted world-wide attention. Langley was the great originator of the science of aerodynamics on this side of the water. Langley studied from artificial birds which he had constructed, and kept almost constantly before him. To Langley, Chanute, Herring, and Manley, America owes much in the way of aeronautics before the Wrights entered the field. The Wrights have given the greatest impetus to modern aviation. They entered the field in 1900, and immediately achieved greater results than any of their predecessors. They followed the idea of Lillianthal to a certain extent. They made gliders in which the aviator had a horizontal position, and they used twice as great a lifting surface as that hitherto employed. The flights of their first motor-machine was made December 17, 1903, at Kitty Hawk, North Carolina. In 1904 with a new machine they resumed experiments at their home near Dayton, Ohio. In September of that year they succeeded in changing the course from one dead against the wind to a curved path where crosscurrents must be encountered, and made many circular flights. During 1906 they rested for a while from practical flight, expecting plans for the future. In the beginning of September 1908 Orville Wright made an airplane flight of one hour, and a few days later stayed up one hour and fourteen minutes. Wilbur Wright went to France and began a series of remarkable flights taking up passengers. On December 31 of that year he startled the world by making the record flight of two hours and nineteen minutes. It was on September 13, 1906 that Santos Dumont made the first officially recorded European airplane flight, leaving the ground for a distance of twelve yards. On November 12 of the same year he remained in the air for twenty-one seconds and travelled a distance of two hundred and thirty yards. These feats caused a great sensation at the time. While the Wrights were achieving fame for America, Henri Farman was busy in England. On October 26, 1907 he flew eight hundred and twenty yards in fifty-two and one-half seconds. On July 6, 1908 he remained in the air for twenty-and-a-half minutes. On October 31, same year, in France, he flew from Chalon to Rem, a distance of sixteen miles in twenty minutes. The year 1909 witnessed mighty strides in the field of aviation. Many of which exceeded the most sanguine anticipations. On July 13, Blerio flew from Etonne to Cheveille, twenty-six miles in forty-four minutes and thirty seconds, and on July 25 he made the first flight across the British Channel, thirty-two miles in thirty-seven minutes. Orville Wright made several sensational flights in his biplane around Berlin, while his brother Wilbur delighted New Yorkers by circling the Statue of Liberty and flying up the Hudson from Governor's Island to Grant's Tomb and return, a distance of twenty-one miles, in thirty-three minutes and thirty-three seconds, during the Hudson-Fulton celebration. On November 20, Louis Paulhan in a biplane flew from Mourmalon to Chalon, France, and return, thirty-seven miles in fifty-five minutes, rising to a height of one-thousand feet. The dirigible airship was also much in evidence during 1909. Zeppelin especially performing some remarkable feats. The Zeppelin V subsequently renumbered number one of the rigid type, four-hundred and forty-six feet long, diameter forty-two-and-a-half feet, and capacity five-hundred and thirty-six thousand cubic feet. On March 29 rose to a height of three-thousand two-hundred and eighty, and on April 1st started with a crew of nine passengers from Friedrichschafen to Munich. In a thirty-five-mile gale it was carried beyond Munich, but Zeppelin succeeded in coming to anchor. Other Zeppelin balloons made remarkable voyages during the year. But the latest achievements, nineteen-ten, of the old German Aeronaut, have put all previous records into the shade and electrified the whole world. This new passenger airship, the Deutschland, on June 22nd made a three-hundred-mile trip from Friedrichschafen to Dusseldorf in nine hours, carrying twenty passengers. This was at the rate of thirty-three point thirty-three miles per hour. During one hour of the journey a speed of forty-three-and-a-half miles was averaged. The passengers were carried in a mahogany finished cabin and had all the comforts of a Pullman car, but most significant fact of all, the trip was made on schedule and with all regularity of an express train. Two days later Zeppelin eclipsed his own record air voyage, when his vessel carried thirty-two passengers, ten of whom were women, in a one-hundred-mile trip from Dusseldorf to Essen, Dortmund, and Bauchem, and back. At one time on this occasion, while travelling with the wind, the airship made a speed of fifty-six-and-a-half miles. It passed through a heavy shower and forced its way against a strong headwind without difficulty. The passengers were all delighted with the new mode of travel, which was very comfortable. This last, dirigible masterpiece of Zeppelin may be styled the Leviathan of the air. It is four-hundred and eighty-five feet long, with a total lifting power of forty-four thousand pounds. It has three motors, which total three-hundred and thirty horse power, and it drives at an average speed of about thirty-three miles an hour. A regular passenger service has been established, and tickets are selling at fifty dollars. The present year can also boast some great airplane records, notably by Curtis and Hamilton in America, and Farman and Paulin in Europe. Curtis flew from Albany to New York, a distance of a hundred and thirty-seven miles at an average speed of fifty-five miles an hour, and Hamilton flew from New York to Philadelphia and returned. The first night flight of a dirigible over New York City was made by Charles Goodale on July 19. He flew from Palisades Park on the Hudson and returned. From a scientific toy the flying machine has been developed and perfected into a practical means of locomotion. It bids fair at no distant date to revolutionize the transit of the world. No other art has ever made such progress in its early stages, and every day witnesses an improvement. The air, though invisible to the eye, has mass, and therefore offers resistance to all moving bodies. Therefore air-mass and air-resistance are the first principles to be taken into consideration in the construction of an airplane. It must be built so that the air-mass will sustain it and the motor, and the motor must be of sufficient power to overcome the air-resistance. A ship plowing through the waves presents the line of least resistance to the water, and so is shaped somewhat like a fish, the natural denizen of that element. It is different with the airplane. In the intangible domain it essays to overcome, there must be a sufficient surface to compress a certain volume of air to sustain the weight of the machinery. The surfaces in regard to size, shape, curvature, bracing, and material are all important. A great deal depends upon the curve of the surfaces. Two machines may have the same extent of surface and develop the same rate of speed, yet one may have a much greater lifting power than the other, provided it has a more efficient curve to its surface. Many people have a fallacious idea that the surfaces of an airplane are planes, and this doubtless arises from the word itself. However, the last syllable in airplane has nothing whatever to do with a flat surface. It is derived from the Greek planos, wandering. Therefore the entire word signifies an air wanderer. The surfaces are really arrow curves arched in the rear of the front edge, thus allowing the supporting surface of the airplane, in passing forward with its backward side set at an angle to the direction of its motion, to act upon the air in such a way as to tend to compress it on the other side. After the surfaces come the rudders in importance. It is a vital consequence that the machine be balanced by the operator. In the present method of balancing an airplane, the idea in mind is to raise the lower side of the machine and make the higher side lower, in order that it can be quickly righted when it tips to one side from a gust of wind, or when making an angle at a sudden turn. To accomplish this two methods can be employed. One, changing the form of the wing, two, using separate surfaces. One side can be made to lift more than the other by giving it a greater curve or extending the extremity. In balancing by means of separate surfaces, which can be turned up or down on each side of the machine, the horizontal balancing rudders are so connected that they will work in an opposite direction. While one is turned to lift one side, the other will act to lower the other side, so as to strike an even balance. The motors and propellers next claim attention. It is the motor that makes aviation possible. It was owing, in a very large measure, to the introduction of the petrol motor that progress became rapid. Hitherto many had laid the blame of everything on the motor. They had said, Give us a light and powerful engine and we will show you how to fly. The first very light engine to be available was the Antoinette, built by Léon L'Avassieux in France. It enabled Santos Dumont to make his first public successful flights. Nearly all airplanes follow the same general principles of construction. Of course a good deal depends upon the form of airplane, whether a monoplane or a biplane. As these two forms are the chief ones, as yet, of heavier than air machines, it would be well to understand them. The monoplane has single large surfaces, like the wings of a bird. The biplane has two large surfaces braced together, one over the other. At the present riding a triplane has been introduced into the domain of American aviation by an English erinote. Doubtless as the science progresses, many other variations will appear in the field. Most machines, though fashioned on similar lines, possess universal features. For instance, the right biplane is characterized by warping wing tips and seams of heavy construction, while the surfaces of the Herring Curtis machine are slight and it looks very light and buoyant as if well suited to its element. The Voisin biplane is fashioned after the manner of a box kite and therefore presents vertical surfaces to the air. The Voisin's machine has no vertical surfaces, but there are hinged wing tips to the outer rear edges of its surfaces for use in turning and balancing. He also has a combination of wheels and skids or runners for starting and landing. The position to be occupied by the operator also influences the construction. Some sit on top of the machine, others underneath. In the Antoinette, Latham sits in a sort of cockpit on the top. Blairios sits far beneath his machine. In the latest construction of Saint-Hos-Dumont, the Demoiselle, the aviator sits on the top. Aeroplanes have been constructed for the most part in Europe, especially in France. There may be said to be only one factory in America, that of Herring Curtis at Hammondsport, New York, as the right place at Dayton is very small, and only turns out motors and experimenting machines, and cannot be called a regular factory. The right machines are now manufactured by a French syndicate. It is said that the rights will have an American factory at work in a short time. The French-made aeroplanes have given good satisfaction. These machines cost from $4,000 to $5,000, and generally have three-cylinder motors, developing from 25 to 35 horsepower. The latest model of Blairios, known as number 12, has beaten the time record of Glenn Curtis's biplane with its 60 horsepower motor. The Farman machine, or the model in which he made the world's duration record in his three hours and 16 minute flights at REM, is one of the best as well as the cheapest of the French makes. Without the motor, it cost but $1,200. It has a surface 25 meters square, is 8 meters long, and 7 and 1 half meters wide, weighs 140 kilos, and has a motor which develops from 25 to 50 horsepower. The right machines cost $6,000. They have four-cylinder motors of 30 horsepower, are 12 and a half meters long, 9 meters wide, and have a surface of 30 square meters. They weigh 400 kilos. In this country they cost $7,500, exclusive of the duty on foreign manufacture. The impetus being given to aviation at the present time by the prizes offered is spurring the men birds to their best efforts. It is prophesied that the airplane will yet attain a speed of 300 miles an hour. The quickest travel yet attained by man has been at the rate of 127 miles an hour. That was accomplished by Marriott in a racing automobile at Ormond Beach in 1906, when he went one mile in 28 and one fifth seconds. It is doubtful, however, were it possible to achieve a rate of 300 miles an hour that any human being could resist the air pressure at such a velocity. At any rate, there can be no question as to the airplane attaining a much greater speed than at present. That it will be useful, there can be little doubt. It is no longer a scientific toy in the hands of amateurs, but a practical machine, which is bound to contribute much to the progress of the world. Of course, as a mode of transportation, it is not in the same class with the dirigible, but it can be made to serve many other purposes. As an agent in time of war, it would be more important than fort or warship. The experiments of Curtis, made a short time ago over Lake Cucca at Hammonsport, New York, prove what a mighty factor would have to be reckoned with in the Marshall airplane. Curtis, without any practice at all, hit a mimic battleship 15 times out of 22 shots. His experiment has convinced the military and naval authorities of this country that the airplane and the aerial torpedo constitute a new danger against which there is no existing protection. Aerial offensive and defensive strategy is now a problem which demands the attention of nations. End of chapter one. Chapter two of marvels of modern science. This is a LibriVox recording. All LibriVox recordings are in the public domain. For more information or to volunteer, please visit LibriVox.org, recording by Kristen Edwards. Marvels of modern science by Paul Severing. Chapter two, wireless telegraphy. At a very early stage in the world's history, man found it necessary to be able to communicate with places at a distance by means of signals. Fire was the first agent employed for the purpose. On hill tops or other eminences, what were known as beacon fires were kindled and owing to their elevation these could be seen for a considerable distance throughout the surrounding country. These primitive signals could be passed on from one point to another until a large region could be covered and many people brought into communication with one another. These fires expressed a language of their own which the observers could readily interpret. For a long time they were the only method used for signaling. Indeed, in many backward localities and in some of the outlying islands and among savage tribes, the custom still prevails. The Bushmen of Australia at nighttime build fires outside their huts or crawls to attract the attention of their followers. Even in enlightened Ireland, the kindling of beacon fires is still observed among the people of backward districts, especially on May Eve and the Festival of Midsummer. On these occasions bonfires are lit on almost every hillside throughout that country. This custom has been handed down from the days of the druids. For a long time fires continued to be the mode of signaling, but as this way could only be used in the night, it was found necessary to adopt some method that would answer the purpose in daytime. Hence signal towers were erected from which flags were waved and various devices displayed. Flags answered the purposes so very well that they came into general use. In course of time they were adopted by the army, navy, and merchant marine, and a regular code established, as at the present time. The railroad introduced the semaphore as a signal and field tactics the heliograph or reflecting mirror, which however is only of service when there is a strong sunlight. Then came the electric telegraph, which not only revolutionized all forms of signaling, but almost annihilated distance. Messages and all sorts of communications could be flashed over the wires in a few minutes, and when a cable was laid under the ocean, continent could converse with continent as if they were next door neighbors. The men who first enabled us to talk over a wire certainly deserve our gratitude. All succeeding generations are their debtors. To the man who enabled us to talk to long distances, without a wire at all, it would seem we owe a still greater debt. But who is this man around whose brow we should twine the laurel wreath, to the altar of whose genius we should carry frankincense and myrrh? This is a question which does not admit of an answer, for to know one man alone do we owe wireless telegraphy, though Hertz was the first to discover the waves which make it possible. However it is to the men whose indefatigable labors and genius made the electric telegraph a reality, that we also owe wireless telegraphy, as we have it at present, for the latter may be considered in many respects the resultant of the former, though both are different in medium. Radio or wireless telegraphy in principle is as old as mankind. Adam delivered the first wireless when on awakening in the Garden of Eden, he discovered Eve and addressed her in the vernacular of Paradise in that famous sentence which translated in English reads both ways the same, Madam, I'm Adam. The oral words issuing from his lips created a sound wave which the medium of the air conveyed to the timpanum of the partner of his joys and the cause of his sorrows. When one person speaks to another the speaker causes certain vibrations in the air, and these so stimulate the hearing apparatus that a series of nerve impulses are conveyed to the sensorium where the meaning of these signals is unconsciously interpreted. In wireless telegraphy the sender causes vibrations not in the air, but in that all pervading and palpable substance which fills all space and which we call the ether. These vibrations can reach out to a great distance and are capable of so affecting a receiving apparatus that signals are made, the movements of which can be interpreted into a distinct meaning and consequently into the messages of language. Let us briefly consider the underlying principles at work. When we cast a stone into a pool of water we observe that it produces a series of ripples which grow fainter and fainter the farther they recede from the center, the initial point of the disturbance, until they fade all together in the surrounding expanse of water. The succession of these ripples is what is known as wave motion. When the clapper strikes the lip of a bell it produces a sound and sends a tremor out upon the air. The vibrations thus made are airwaves. In the first of these cases the medium communicating the ripple or wavelet is the water. In the second case the medium which sustains the tremor and communicates the vibrations is the air. Let us now take the case of a third medium, the substance of which puzzled the philosophers of ancient time and still continues to puzzle the scientists of the present. This is the ether that attenuated fluid which fills all interstellar space and all space in masses and between molecules and atoms not otherwise occupied by gross matter. When a lamp is lit the light radiates from it in all directions in a wave motion. That which transmits the light, the medium, is ether. By this means energy is conveyed from the sun to the earth and scientists have calculated the speed of the ether vibrations called light at 186,400 miles per second. Thus a beam of light can travel from the sun to the earth a distance between 92 million and 95 million miles according to season in a little over eight minutes. The fire messages sent by the ancients from hill to hill were ether vibrations. The greater the fires the greater were the vibrations and consequently they carried farther to the receiver, which was the eye. If a signal is to be sent a great distance by light the source of that light must be correspondingly powerful in order to disturb the ether sufficiently. The same principle holds good in wireless telegraphy. If we wish to communicate to a great distance the ether must be disturbed in proportion to the distance. The vibrations that produce light are not sufficient in intensity to affect the ether in such a way that signals can be carried to a distance. Other disturbances however can be made in the ether stronger than those which create light. If we charge a wire with an electric current and place a magnetic needle near it we find it moves the needle from one position to another. This effect is called an electromagnetic disturbance in the ether. Again when we charge an insulated body with electricity we find it attracts any light substance indicating a material disturbance in the ether. This is described as an electrostatic disturbance or effect and it is upon this that wireless telegraphy depends for its operations. The late German physicist Dr. Heinrich Hertz, PhD, was the first to detect electrical waves in the ether. He set up the waves in the ether by means of an electrical discharge from an induction coil. To do this he employed a very simple means. He procured a short length of wire with a brass knob at either end and bent around so as to form an almost complete circle leaving only a small air gap between the knobs. Each time there was a spark discharged from the induction coil the experimenter found that a small electric spark also generated between the knobs of the wire loop thus showing that electric waves were projecting through the ether. This discovery suggested to scientists that such electric waves might be used as a means of transmitting signals to a distance through the medium of the ether without connecting wires. When Hertz discovered that electric waves crossed space he unconsciously became the father of the modern system of radio telegraphy and though he did not live to put or see any practical results from his wonderful discovery to him in a large measure should be accorded the honor of blazing the way for many of the intellectual giants who came after him. Of course those who went before him who discovered the principles of the electric telegraph made it possible for the Hertzian waves to be utilized in wireless. It is easy to understand the wonders of wireless telegraphy when we consider that electric waves traverse space in exactly the same manner as light waves. When energy is transmitted with finite velocity we can think of its transference only in two ways. First by the actual transference of matter as when a stone is hurled from one place to another. Second by the propagation of energy from point to point through a medium which fills the space between two bodies. The body sending out energy disturbs the medium contiguous to it which disturbance is communicated to adjacent parts of the medium and so the movement is propagated outward from the sending body through the medium until some other body is affected. A vibrating body sets up vibrations in another body as for instance when one tuning fork responds to the vibrations of another when both have the same note or are in tune. The transmission of messages by wireless telegraphy is affected in a similar way. The apparatus at the sending station sends out waves of a certain period through the ether and these waves are detected at the receiving station by apparatus attuned to this wavelength or period. The term electric radiation was first employed by Hertz to designate waves emitted by a laden jar or oscillator system of an induction coil but since that time these radiations have been known as Hertzian waves. These waves are the underlying principles in wireless telegraphy. It was found that certain metal filings offered great resistance to the passage of an electric current through them but that this resistance was very materially reduced when electric waves fell upon the filings and remained so until the filings were shaken. Thus giving time for the fact to be observed in an ordinary telegraphic instrument. The tube of filings through which the electric current is made to pass in wireless telegraphy is called a coherer signifying that the filings cohere or cling together under the influence of the electric waves. Almost any metal will do for the filings but it is found that a combination of 90 percent nickel and 10 percent silver answers the purpose best. The tube of the coherer is generally of glass but any insulating substance will do. A wire enters at each end and is attached to little blocks of metal which are separated by a very small space. It is into this space the filings are loosely filled. Another form of coherer consists of a glass tube with small carbon blocks or plugs attached to the ends of the wires and instead of the metal filings there is a globule of mercury between the plugs. When electric waves fall upon this coherer the mercury coheres to the carbon blocks and thus forms a bridge for the battery current. Marconi and several others have from time to time invented many other kinds of detectors for the electrical waves. Nearly all have to serve the same purpose that is to close a local battery circuit when the electric waves fall upon the detector. There are other inventions on which the action is the reverse. These are called anti-coherers. One of the best known of these is a tube arranged in a somewhat similar manner to the filings tube but with two small blocks of tin between which is placed a paste made up of alcohol tin filings and lead oxide. In its normal state the paste allows the battery current to get across from one block to another but when electric waves touch it a chemical action is produced which immediately breaks down the bridge and stops the electric waves. The paste resumes its normal condition and allows the battery current to pass again. Therefore by this arrangement the signals are made by a sudden breaking and making of the battery circuit. Then there is the magnetic detector. This is not so easy of explanation. When we take a piece of soft iron and continuously revolve it in front of a permanent magnet the magnetic poles of the soft iron piece will keep changing their position at each half revolution. It requires a little time to affect this magnetic change which makes it appear as if a certain amount of resistance was being made against it. If electric waves are allowed to fall upon the iron resistance is completely eliminated and the magnetic poles can change places instantly as it revolves. From this we see that if we have a quickly changing magnetic field it will induce or set up an electric current in a neighboring coil of wire. In this way we can detect the changes in the magnetic field for we can place a telephone receiver in connection with the coil of wire. In a modern wireless receiver of this kind it is found more convenient to replace the revolving iron piece by an endless band of soft iron wire. This band is kept passing in front of a permanent magnet. The magnetism of the wire tending to change as it passes from one pole to the other. This change takes place suddenly when the electric waves form the transmitting station, fall upon the receiving aerial conductor and are conducted around the moving wire and as the band is passing through a coil of insulated wire attached to a telephone receiver this sudden change in the magnetic field induces an electric current in the surrounding coil and the operator hears a sound in the telephone at his ear. The Morse code may thus be signaled from the distant transmitter. There are various systems of wireless telegraphy for the most part called after the scientists who developed or perfected them. Probably the foremost as well as the best known is that which bears the name of Marconi. A popular fallacy makes Marconi the discoverer of the wireless method. Marconi was the first to put the system on a commercial footing or business basis and to lead the way for its coming to the front as a mighty factor in modern progress. Of course also the honor of several useful inventions and additions to wireless apparatus must be given him. He started experimenting as far back as 1895 when by a mere boy. In the beginning he employed the induction coil, Morse telegraph key, batteries and vertical wire for the transmission of signals and for the reception the usual filings coherer of nickel with a very small percentage of silver, a telegraph relay, batteries and a vertical wire. In the Marconi system of the present time there are many forms of coherers also the magnetic detector and other variations of the original apparatus. Other systems more or less prominent are the Lodge Muirhead of England, Brown Siemens of Germany and those of de Forest and Fessenden of America. The electrolytic detector with the pace between the 10 blocks belongs to the system of de Forest. Besides these the names of Popov, Jackson, Armstrong, Orling, Lepel and Poulsen stand high in the wireless world. A serious drawback to the operations of wireless lies in the fact that the stations are liable to get mixed up and someone intercepts the messages intended for another but this is being overcome by the adoption of a special system of wavelengths for the different wireless stations and by the use of improved apparatus. In the early days it was quite a common occurrence for the receivers of one system to reply to the transmitters of a rival system. There was an all-round mix up and consequently the efficiency of wireless for practical purposes was for a good while looked upon with more or less suspicion but as knowledge of wave motions developed and the laws of governing them were better understood the receiver was tuned to respond to the transmitter that is the transmitter was made to set up a definite rate of vibrations in the ether and the receiver made to respond to this rate just like two tuning forks sounding the same note. In order to set up as energetic electric waves as possible many methods have been devised at the transmitting stations. In some methods a wire is attached to one of the two metal spheres between which the electric charge takes place and is carried up into the air for a great height while to the second sphere another wire is connected and which leads into the earth. Another method is to support a regular network of wires from strong steel towers built to a height of 200 feet or more. Long distance transmission by wireless was only made possible by grounding one of the conductors in the transmitter. The Hertzian waves were provided without any earth connection and radiated into space in all directions rapidly losing force like the disappearing ripples on a pond whereas those set up by a grounded transmitter with the receiving instruments similarly connected to earth keep within the immediate neighborhood of the earth. For instance up to about 200 miles a storage battery and induction coil are sufficient to produce the necessary ether disturbance but when a greater distance is to be spanned an engine and a dynamo are necessary to supply energy for the electric waves. In the most recent Marconi transmitter the current produced is no longer in the form of intermittent sparks but is a true alternating current which in general continues uniformly as long as the key is pressed down. There is no longer any question that wireless telegraphy is here to stay. It has passed the juvenile stage and is fast approaching a lusty adolescence which promises to be a source of great strength to the commerce of the world. Already it has accomplished much for its age. It has saved so many lives at sea that its installation is no longer regarded as a scientific luxury but a practical necessity on every passenger vessel. Practically every steamer in American waters is equipped with a wireless station. Even freight boats and tugs are up to date in this respect. Every ship in the American navy including colliers and revenue cutters carries wireless operators. So important indeed is it considered in the navy department that a line of shore stations have been constructed from Maine on the Atlantic to Alaska on the Pacific. In a remarkably short interval wireless has come to exercise an important function in the marine service. Through the shore stations of the commercial companies press dispatches, storm warnings, weather reports and other items of interest are regularly transmitted to ships at sea. Captains keep in touch with one another and with the home office. Rex derelicts and storms are reported. Every operator sends out regular reports daily so that the home office can tell the exact position of the vessel. If she is too far from land on the one side to be reached by wireless she is near enough on the other to come within the sphere of its operations. Weather has no effect on wireless therefore the question of meteorology does not come into consideration. Fogs, rains, torrents, tempests, snowstorms, winds, thunder, lightning or any aerial disturbance whatsoever cannot militate against the sending or receiving of wireless messages as the ether permeates them all. Submarine and land telegraphy used to look on wireless the youngest sister as the Cinderella of their name but she has surpassed both and captured the honors of the family. It was in 1898 that Marconi made his first remarkable success in sending messages from England to France. The English station was at South Foreland and the French near Belon. The distance was 32 miles across the British Channel. This telegraphic communication without wires was considered a wonderful feat at the time and excited much interest. During the following year Marconi had so much improved his first apparatus that he was able to send out waves detected by receivers up to the 100 mile limit. In 1900 communication was established between the Isle of White and the Lizard in Cornwall a distance of 200 miles. Up to this time the only appliances employed were induction coils giving a 10 or 20 inch spark. Marconi and others perceived the necessity of employing greater force to penetrate the ether in order to generate stronger electrical waves. Oil and steam engines and other appliances were called into use to create high frequency currents and those necessitated the erection of large power stations. Several were erected at advantageous points and the wireless system was fairly established as the new agent of communication. In December 1901 at St. John's Newfoundland Marconi by means of kites and balloons set up a temporary aerial wire in the hope of being able to receive a signal from the English station in Cornwall. He had made an arrangement with poll do station that on a certain date and at a fixed hour they should attempt the signal. The letter S which in the Morse code consists of three successive dots was chosen. Marconi feverishly awaited results. True enough on the day and at the time agreed upon the three dots were clicked off the first signal from Europe to the American continent. Marconi with much difficulty set up other aerial wires and indubitably established the fact that it was possible to send electric waves across the Atlantic. He found however that waves in order to traverse 3000 miles and retain sufficient energy on their arrival to affect a telephonic wave detecting device must be generated by no inordinate power. These experiments proved that if stations were erected of sufficient power transatlantic wireless could be successfully carried on. They gave an impetus to the erection of such stations. On December 21st 1902 from a station at Glass Bay, Nova Scotia Marconi sent the first message by wireless to England announcing success to his colleagues. The following January from Wells Fleet Cape Cod President Roosevelt sent a congratulatory message to King Edward. The electric waves conveying this message traveled 3000 miles over the Atlantic following round an arc of 45 degrees of the earth on a great circle and were received telephonically by the Marconi Magnetic Receiver at Poldew. Most ships are provided with syntonic receivers which are tuned to long distance transmitters and are capable of receiving messages up to distances of 3000 miles or more. Wireless communication between Europe and America is no longer a possibility but an accomplishment though as yet the system has not been put on a general business basis. Footnote as we go to press a new record has been established in wireless transmission. Marconi in the Argentine Republic near Buenos Aires has received messages from the station at Clifton County Galway Ireland a distance of 5600 miles. The best previous record was made when the United States Battleship Tennessee in 1909 picked up a message from San Francisco when 4580 miles distant. End of Chapter 2 Chapter 3 Of Marvels of Modern Science This is a LibriVox recording. All LibriVox recordings are in the public domain. For more information or to volunteer please visit LibriVox.org Marvels of Modern Science by Paul Severing Chapter 3 Radium Experiments of Becquerel Work of the Curies Discovery of Radium Enormous Energy Various Uses Early in 1896 just a few months after Röntgen had startled the scientific world by the announcement of the discovery of the X-rays Professor Henri Becquerel of the Natural History Museum in Paris announced another discovery which, if not as mysterious, was more puzzling and still continues a puzzle to a great degree to the present time. Studying the action of the salts of a rare and very heavy mineral called uranium Becquerel observed that their substances give off an invisible radiation which, like the Röntgen rays, traverse metals and other bodies opaque to light as well as glass and other transparent substances. Like most of the great discoveries it was a result of an accident. Becquerel had no idea of such radiations had never thought of their possibility. In the early days of the Röntgen rays there were many facts which suggested that phosphorescence had something to do with the production of these rays. It then occurred to several French physicists that X-rays might be produced if phosphorescent substances were exposed to sunlight. Becquerel began to experiment with a view to testing this supposition. He placed uranium on a photographic plate which had first been wrapped in black paper in order to screen it from the light. After this plate had remained in the bright sunlight for several hours it was removed from the paper covering and developed. A slight trace of photographic action was found at those parts of the plate directly beneath the uranium, just as Becquerel had expected. From this it appeared evident that rays of some kind were being produced that were capable of passing through black paper. Since the X-rays were the only ones known to possess the power to penetrate opaque substances it seemed as though the problem of producing X-rays by sunlight was solved. Then came the fortunate accident. After several plates had been prepared for exposure to sunlight a severe storm arose and the experiments had to be abandoned for the time being. At the end of several days work was resumed but the plates had been lying so long in the darkroom that they were deemed almost valueless and it was thought that there would be not much use in trying to use them. Becquerel was about to throw them away but on second consideration thinking that some action might have possibly taken place in the dark he resolved to try them. He developed them and the result was that he obtained better pictures than ever before. The exposure to sunlight which had been regarded as essential to the success of the former experiments had really nothing at all to do with the matter. The essential thing was the presence of uranium and the photographic effects were not due to X-rays but to the rays or emanations which Becquerel had thus discovered and which bear his name. There were many tedious and difficult steps to take before even our present knowledge incomplete as it is could be reached. However Becquerel's fortunate accident of the plate developing was the beginning of the long series of experiments which led to the discovery of radium which already had revolutionized some of the most fundamental conceptions of physics and chemistry. It is remarkable that we owe the discovery of this wonderful element to a woman Madame Sladovska Curie the wife of a French professor and physicist. Madame Curie began her work in 1897 with a systematic study of several minerals containing uranium and thorium and soon discovered the remarkable fact that there was some agent present more strongly radioactive than the metal uranium itself. She set herself the task of finding out this agent and in conjunction with her husband Professor Pierre Curie made many tests and experiments. Finally in the oar of pitch blend they found not only one but three substances highly radioactive. Pitch blend or uraniumite is an intensely black mineral of a specific gravity of 9.5 and is found in commercial quantities in Bohemia, Cornwall in England and some other localities. It contains lead sulfide, lime silica and other bodies. To the radioactive substance which accompanied the bismuth extracted from pitch blend the Curie's gave the name polonium to that which accompanied barium taken from the same oar they called radium and to the substance which was found among the rare earths of the pitch blend Debiharina gave the name actinium. None of these elements have been isolated that is to say separated in a pure state from the accompanying oar. Therefore pure radium is a misnomer though we often hear the term used. Footnote Since the above was written Madame Curie has announced to the Paris Academy of Sciences that she has succeeded in obtaining pure radium. In conjunction with Professor Debiharina she treated a desigram of bromide of ramium by electrolytic process getting an amalgam from which was extracted the metallic radium by distillation and a footnote. All that has been obtained is some of its simpler salts or compounds and until recently even these had not been prepared in pure form. The commonest form of the element which in itself is very far from common is what is known to chemistry as chloride of radium which is a combination of chlorine and radium. This is a grayish white powder somewhat like ordinary coarse table salt. To get enough to weigh a single grain requires the treatment of 1200 pounds of pitch blend. The second form of radiation is as a bromide. In this form it costs $5,000 a grain and could a pound be obtained its value would be three and a half million dollars. Radium as we understand it in any of its compounds can communicate its property of radioactivity to other bodies. Any material when placed near radium becomes radioactive and retains such activity for a considerable time after being removed. Even the human body takes on this excited activity and this sometimes leads to annoyances as in delicate experiments the results may be nullified by the element acting upon the experimenter's person. Despite the enormous amount of energy given off by radium it seems not to change in itself. There is no appreciable loss of weight nor apparently any microscopic or chemical change in the original body. Professor Becquerel has stated that if a square centimeter of surface was covered by chemically pure radium it would lose but one thousandth of a milligram in weight in a million years time. Radium is a body which gives out energy continuously and spontaneously. This liberation of energy is manifested in the different effects of its radiation and emanation and especially in the development of heat. Now according to the most fundamental principles of modern science the universe contains a certain definite provision of energy which can appear under various forms but which cannot be increased. According to Sir Oliver Lodge every cubic millimeter of ether contains as much energy as would be developed by a million horsepower station working continuously for forty thousand years. This assertion is probably based on the fact that every corpuscle in the ether vibrates with the speed of light for about 186,000 miles a second. It was formally believed that the atom was the smallest subdivision in nature. Scientists held to the atomic theory for a long time but at last it has been exploded and instead of the atom being primary and indivisible we find it a very complex affair a kind of miniature solar system the center of a varied attraction of molecules corpuscles and electrons. Had we held to the atomic theory and denied smaller subdivisions of matter there would be no accounting for the emissions of radium. For as science now believes these emissions are merely the expulsion of millions of electrons. Radium gives off three distinct types of rays named after the first three letters of the Greek alphabet alpha beta gamma. Besides a gas emanation as does thorium which is a powerfully radioactive substance. The alpha rays constitute 99% of all the rays and consist of positively electrified particles. Under the influence of magnetism they can be deflected. They have little penetrative power and are readily absorbed and passing through a sheet of paper or through a few inches of air. The beta rays consist of negatively charged particles or corpuscles approximately one thousandth the size of those constituting the alpha rays. They resemble cathode rays reduced by an electrical discharge inside of a highly exhausted vacuum tube. But work at a much higher velocity. They can be readily deflected by a magnet. They discharge electrified bodies, affect photographic plates, stimulate strongly phosphorescent bodies and are of a high penetrative power. The radiations are a million times more powerful than those of uranium. They have many curious properties. If a photographic plate is placed in the vicinity of radium it is almost instantly affected if no screen intercepts the rays. With a screen the action is slower but it still takes place even through thick folds. Therefore radiographs can be taken and in this way it is being utilized by surgery to view the anatomy, the internal organs and locate bullets and other foreign substances in the system. A glass vessel containing radium spontaneously charges itself with electricity. If the glass has a weak spot, a scratch, say. An electric spark is produced at that point and the vessel crumbles, just like a lightened jar when overcharged. Radium liberates heat spontaneously and continuously. A solid salt of radium develops such an amount of heat that to every single gram there is an emission of 100 calories per hour. In other words, radium can melt its weight in ice in the time of one hour. As a result of its emission of heat radium has always a temperature higher by several degrees than its surroundings. When a solution of radium salt is placed in a closed vessel the radioactivity in part leaves the solution and distributes itself through the vessel. The sides of which become radioactive and luminous. Radium acts upon the chemical constituents of glass, porcelain, paper, giving them a violet tinge. Changes white phosphorus into yellow, oxygen into ozone and produces many other curious chemical changes. We have said that it can serve the surgeon in physical examinations of the body after the manner of x-rays. It has not however been much employed in this direction owing to its scarcity and prohibitive price. It has given excellent results in the treatment of certain skin diseases and cancer, etc. However, it can have very baneful effects on animal organisms. It has produced paralysis and death in dogs, cats, rabbits, rats, guinea pigs and other animals and undoubtedly it might affect human beings in a similar way. Professor Curie said that a single gram of chemically pure radium would be sufficient to destroy the life of every man, woman and child in Paris, providing they were separately and properly exposed to its influence. Radium destroys the germinative power of seeds and retards the growth of certain forms of life, such as larvae, so that they do not pass into the chrysalis and insect stages of development, but remain in the state of larvae. At a certain distance, it causes the hair of mice to fall out, but on the contrary, at the same distance, it increases the hair or fur on rabbits. It often produces severe burns on the hands and other portions of the body too long exposed to its activity. It can penetrate through gases, liquids and all ordinary solids, even through many inches of the hardest steel. On a comparatively short exposure, it has been known to partially paralyze an electric charged bar. Heat, nor cold, do not affect its radioactivity in the least. It gives off but little light, its luminosity being largely due to the stimulation of the impurities in the radium by the powerful but invisible radium rays. Radium stimulates powerfully various mineral and chemical substances near which it is placed. It is an infallible test of the genuineness of the diamond. The genuine diamond phosphoresces strongly and brought into juxtaposition, but the paste or imitation one glows not at all. It is seen that the study of the properties of radium is of great interest. This is true also of the other two elements found in the ores of uranium and thorium, that is, polonium and actinium. Polonium, so-called in honor of the native land of Madam Curie, is just as active as radium when first extracted from the pitch blend, but its energy soon lessens and finally becomes inert. Hence there has been little experimenting or investigation. The same may be said of actinium. The process of obtaining radium from pitch blend is most tedious and laborious and requires much patience. The residue of the pitch blend, from which uranium has been extracted by fusion with sodium carbonate and solution in dilute sulfuric acid, contains the radium along with other metals and is boiled with concentrated sodium carbonate solution and the solution of the residue in hydrochloric acid precipitated with sulfuric acid. The insoluble barium and radium sulfates, after being converted into chlorides or bromides, are separated by repeated fractional crystallization. One kilogram of impure radium bromide is obtained from a ton of pitch blend residue. After processes continued for about three months, during which time, five tons of chemicals and fifty tons of rinsing water are used. As has been said, the element has never been isolated or separated in its metallic or pure state and most of the compounds are impure. Radium banks have been established in London, Paris and New York. Whenever radium is employed in surgery for an operation, about fifty milligrams are required, at least, and the banks let out the amount for about two hundred dollars a day. If purchased, the price for this amount would be four thousand dollars. End of Chapter 3 Chapter 4 of Marvels of Modern Science This is a LibriVox recording. All LibriVox recordings are in the public domain. For more information or to volunteer, please visit LibriVox.org. Recording by Louise J. Bell Marvels of Modern Science by Paul Severing Chapter 4 Moving Pictures Photographing motion Edison's kinetoscope Lumière's cinematograph Before the camera The mission of the moving picture Few can realize the extent of the field covered by moving pictures. In the dual capacity of entertainment and instruction, there is not a rival in sight. As an instructor, science is daily widening the sphere of the motion picture. For the purpose of illustration. Films are rapidly superseding textbooks in many branches. Every department capable of photographic demonstration is being covered by moving pictures. Negatives are now being made of the most intricate surgical operations. And these are teaching the students better than the witnessing of the real operations. For at the critical moment of the operation, the picture machine can be stopped to let the student view over again the way it is accomplished. Whereas at the operating table, the surgeon must go on with his work to try to save life and cannot explain every step in the process of the operation. There is no doubt that the moving picture machine will perform a very important part in the future teaching of surgery. In the naturalist's domain of science, it is already playing a very important part. A device for micro photography has now been perfected in connection with motion machines, whereby things are magnified to a great degree. By this means, the analysis of a substance can be better illustrated than anyway else. For instance, a drop of water looks like a veritable zoo with terrible looking creatures wiggling and wriggling through it, and makes one feel as if he never wanted to drink water again. The moving picture in its general phase is entertainment and instruction rolled into one. And as such, it has superseded the theater. It is estimated that at the present time in America, there are upwards of 20,000 moving picture shows, patronized daily by almost 10 million people. It is doubtful if the theater attendance at the best day of the winter season reaches 5 millions. The moving picture in importance is far beyond the puny functions of comedy and tragedy, the grotesque farce of vaudeville, and the tawdry show, which only appeals to sentiment at highest and often to the base passions at lowest. Despite prurient opposition, it is making rapid headway. It is entering very largely into the instructive and the entertaining departments of the world's curriculum. Millions of dollars are annually expended in the production of films. Companies of trained and practiced actors are brought together to enact pantomimes, which will concentrate within the space of a few minutes, the most entertaining and instructive incidents of history, and the leading happenings of the world. At all great events, no matter where transpiring, the different moving picture companies have trained men at the front, ready with their cameras to catch every incident, every movement, even to the wink of an eyelash, so that the stay-at-homes can see the show as well and with a great deal more comfort than if they had traveled hundreds or even thousands of miles to be present in propria persona. How did moving pictures originate? What and when were the beginning? It is popularly believed that animated pictures had their inception with Edison. Who projected the biograph in 1887, having based it on that wonderful and ingenious toy, the Zoetrope. Long before 1887, however, several men of inventive faculties had turned their attention to a means of giving apparent animation to pictures. The first that met with any degree of success was Edward Mybridge, a photographer of San Francisco. This was in 1878. A revolution had been brought about in photography by the introduction of the instantaneous process. By the use of sensitive films of gelatin bromide of silver emulsion, the time required for the action of ordinary daylight in producing a photograph had been reduced to a very small fraction of a second. Mybridge utilized these films for the photographic analysis of animal motion. Beside a race track, he placed a battery of cameras, each camera being provided with a spring shutter, which was controlled by a thread stretched across the track. A running horse broke each thread the moment he passed in front of the camera, and thus 20 or 30 pictures of him were taken in close succession within one or two seconds of time. From the negatives secured in this way, a series of positives were obtained in proper order on a strip of sensitized paper. The strip, when examined by means of the zoetrope, furnished a reproduction of the horse's movements. The zoetrope was a toy familiar to children. It was sometimes called the Wheel of Life. It was a contrivance consisting of a cylinder some 10 inches wide, open at the top, around the lower and interior rim of which a series of related pictures were placed. The cylinder was then rapidly rotated, and the spectator, looking through the vertical narrow slits on its outer surface, could fancy that the pictures inside were moving. Mybridge devised an instrument, which he called a zoopraxiscope, for the optical projection of his zoetrope photographs. The succession of positives was arranged in proper order upon a glass disc about 18 inches in diameter near its circumference. This disc was mounted conveniently for rapid revolution, so that each picture would pass in front of the condenser of an optical lantern. The difficulties involved in the preparation of the disc pictures, and in the manipulation of the zoopraxiscope, prevented the instrument from attracting much attention. However, artistically speaking, it was the forerunner of the numerous graphs and scopes and moving picture machines of the present day. It was in 1887 that Edison conceived an idea of associating with his phonograph, which had then achieved a marked success, an instrument which would reproduce to the eye the effect of motion by means of a swift and graded succession of pictures, so that the reproduction of articulate sounds, as in the phonograph, would be accompanied by the reproduction of the motion naturally associated with them. The principle of the instrument was suggested to Edison by the zoetrope, and of course he well knew what Mybridge had accomplished in the line of motion pictures of animals, almost 10 years previously. Edison however did not employ a battery of cameras, as Mybridge had done, but devised a special form of camera in which a long strip of sensitized film was moved rapidly behind a lens provided with a shutter and so arranged as to alternately admit and cut off the light from the moving object. He adjusted the mechanism so that there were 46 exposures a second, the film remaining stationary during the momentary time of exposure, after which it was carried forward far enough to bring a new surface into the proper position. The time of the shifting was about one-tenth of that allowed for exposure, so that the actual time of exposure was about one-fiftieth of a second, the film moved, reckoning shiftings and stoppages for exposures at an average speed of a little more than a foot per second, so that a length of film of about 50 feet received between 700 and 800 impressions in a circuit of 40 seconds. Edison named his first instrument the kinetoscope. It came out in 1893. It was hailed with delight at the time and for a short period was much in demand, but soon new devices came into the field and the kinetoscope was superseded by other machines bearing similar names with a like signification. A variety of cameras was invented, one consisted of a film-feeding mechanism which moves the film step-by-step in the focus of a single lens, the duration of exposure being from 20 to 25 times as great as that necessary to move an unexposed portion of the film into position. No shutter was employed. As time passed, many other improvements were made. An ingenious Frenchman named Lumière came forward with his cinématograph which for a few years gave good satisfaction, producing very creditable results. Success, however, was due more to the picture ribbons than to the mechanism employed to feed them. Of other moving picture machines we have had the vitoscope, vitograph, magnoscope, mutoscope, panorama graph, theatograph, and scores of others all derived from the two Greek roots grafo, right, and scopeo, view. The vitoscope is the principal name now in use for motion picture machines. In all these instruments, in order that the film projection may be visible to an audience, it is necessary to have a very intense light. A source of such light is found in the electric focusing lamp. At or near the focal point of the projecting lantern condenser, the film is made to travel across the field as in the kinetoscope. A water cell in front of the condenser absorbs most of the heat and transmits most of the light from the arc lamp. And the small picture, thus highly illuminated, is protected from injury. A projecting lens of rather short focus throws a large image of each picture on the screen. And the rapid succession of these completes the illusion of lifelike motion. Hundreds of patents have been made on cameras, projecting lenses and machines, from the days of the kinetoscope to the present time, when clear-cut moving pictures portray life so closely and so well as almost to deceive the eye. In fact, in many cases, the counterfeit is taken for the reality. And audiences, as much aroused as if they were looking upon a scene of actual life. We can well believe the story of the Irishman, who, on seeing the stage villain abduct the young lady, made a rush at the canvas, yelling out, let me at the blaggard, and I'll murder him. Though but fifteen years old, the moving picture industry has sent out its branches into all civilized lands, and is giving employment to an army of thousands. It would be hard to tell how many mimic actors and actresses make a living by posing for the camera. Their name is Legion. Among them are many professionals who receive as good a salary as on the stage. Some of the large concerns, both in Europe and America, at times employ from one hundred to two hundred hands, and even more, to illustrate some of the productions. They send their photographers and actors all over the world for settings. Most of the business, however, is done near home. With trapping and other paraphernalia, a stage setting can be effected to simulate almost any scene. Almost anything under the sun can be enacted in a moving picture studio, from the drowning of a cat, to the hanging of a man. A horse race, or fire alarm, is not outside the possible, and an aviator has been depicted flying high in the heavens. The places where the pictures are prepared must be adapted for the purpose. They are called studios, and have glass roofs, and in most of them a good section of the walls are also glass. The floor space is divided into sections for the setting or staging of different productions. Therefore, several representations can take place at the same time, before the eyes of the cameras. There are properties of all kinds, from the ragged garments of the beggar, to kingly ermine and queenly silks. Paced diamonds sparkle in necklaces, crowns, and tiaras. Seeming to rival the scintillations of the koanur. At the first, objections were made to moving pictures, on the ground that, in many cases, they had a tendency to cater to the lower instincts. That subjects were illustrated which were repugnant to the finer feelings, and appealed to the gross and the sensual. Burglaries, murders, and wild western scenes, in which the villain-heroes triumphed, were often shown, and, no doubt, these had somewhat of a pernicious influence on susceptible youth. But all such pictures have, for the most part, been eliminated. And there is a strict taboo on anything with a degrading influence, or partaking of the brutal. Prize fights are often barred. In many large cities there is a board of censorship, to which the different manufacturing firms must submit duplicates. This board has to pass on all the films before they are released. And if the pictures are in any way, contrary to morals or decency, or are in any respect unfit to be displayed before the public, they cannot be put in circulation. Thus are the people protected, and especially the youth, who should be permitted to see nothing that is not elevating, or not of a nature to inspire them with high and noble thoughts, and with ambitions to make the world better and brighter. Let us hope that the future mission of the moving picture will be along educational and moral lines, tending to uplift and ennoble our boys and girls, so that they may develop into a manhood and womanhood worthy of the history and best traditions of our country. The Wizard of Menlo Park has just succeeded after two years of hard application to the experiment in giving us the talking picture. A real, genuine talking picture, wholly independent of the old device of having the actors talk behind the screen when the films were projected. By a combination of the phonograph and the moving picture machine, working in perfect synchronism, the result is obtained. Wires are attached to the mechanism of both the machines, the one behind the screen and the one in front, in such a way that the two are operated simultaneously, so that when a film is projected, a corresponding record on the phonograph acts in perfect unison, supplying the voice suitable to the moving action. Men and women pass along the canvas, act, talk, laugh, cry and have their being just as in real life. Of course, they are immaterial, merely the reflection of films, but the one hundred thousandth of an inch thick. Yet they give forth oral sounds as creatures of flesh and blood. In fact, every sound is produced harmoniously with the action on the screen. An iron ball is dropped and you hear its thud upon the floor. A plate is cracked and you can hear the cracking, just the same as if the material plate were broken in your presence. An immaterial piano appears upon the screen and a fleshless performer discourses airs, as real as those heard on Broadway. Melba and Tetrazini and Caruso and Bonci appear before you and warble their nightingale notes as if behind the footlights with a galaxy of beauty, wealth and fashion before them for an audience. True, it is not even their astral bodies you are looking at, only their pictured representations. But the magic of their voices is there all the same and there is such an atmosphere of realism about the representations that you can scarcely believe the actors are not present in propria persona. Mr. Edison had much study and labor of experiment in bringing his device to a successful issue. The greatest obstacle he had to overcome was in getting a phonograph that could hear far enough. At the beginning of the experiments, the actor had to talk directly into the horn, which made the right kind of pictures impossible to get. Bit by bit, however, a machine was perfected which could hear so well that the actor could move at his pleasure within a radius of 20 feet. That is the machine that is being used now. This new combination of the moving picture machine and the phonograph, Edison has named the kinetophone. By it, he has made possible the bringing of grand opera into the hamlets of the West. And through it also, our leading statesmen may address audiences on the mining camps and the wilds of the prairies where their feet have never trodden. End of Chapter 4. Chapter 5 of Marvels of Modern Science. This is a LibriVox recording. All LibriVox recordings are in the public domain. For more information or to volunteer, please visit LibriVox.org. Recording by Avae in April 2020. Marvels of Modern Science by Paul Severing. Chapter 5. Skyscrapers and How They Are Built. Evolution of the Skyscraper. Construction. New York's Giant Buildings. Dimensions. The Skyscraper is an architectural triumph, but at the same time it is very much of a commercial enterprise and it is indigenous, native-born to American soil. It had its inception here, particularly in New York and Chicago. The tallest buildings in the world are in New York. The most notable of these, the Metropolitan Life Insurance Building, with 50 stories towering up to a height of 700 feet and 3 inches, has been the crowning achievement of architectural art, the highest building yet erected by man. How is it possible to erect such a building? How is it possible to erect the Skyscraper at all? A partial answer may be given in one word. Steel. Generally speaking, the method of building all these huge structures is much the same. Massive piers or pillars are erected, inside which are usually strong steel columns. Crosswise from column to column, great girders are placed forming a base for the floor, and then upon the first pillars are raised other steel columns, slightly decreased in size, upon which girders are again fixed for the next floor, and so on this process is continued floor after floor. There seems no reason why buildings should not be reared like this for even a hundred stories, provided the foundations are laid deep enough and broad enough. The walls are not really the support of the buildings. The essential elements are the columns and girders of steel forming the skeleton framework of the whole. The masonry may assist, but the piers and girders carry the principal weight. If, therefore, everything depends upon these piers, which are often of steel and masonry combined, the immense importance will be seen of basing them upon adequate foundations. And thus it comes about that to build high, we must dig deep, which fact may be construed as an aphorism to fit more subjects than the building of skyscrapers. To attempt to build a skyscraper without a suitable foundation would be tent amount to endeavoring to build a house on a marsh without draining the marsh. It would count failure at the very beginning. The formation depends on the height, the calculated weight the framework will carry, the amount of air pressure, the vibrations from the running of internal machines, and several other details of less importance than those mentioned, but of deep consequence in the aggregate. Instead of being carried on thick walls spread over a considerable area of ground, the skyscrapers are carried wholly on steel columns. This concentrates many hundred tons of load and develops pressure which would crush the masonry and cause the structures to penetrate soft earth almost as a stone sinks in water. In the first place the weight of the proposed building and contents is estimated, then the character of the soil determined to a depth of 100 feet if necessary. In New York the soil is treacherous and difficult, there are underground rivers in places and large deposits of sand so that to get down to rock bottom or pan is often a very hard undertaking. Generally speaking the excavations are made to about a depth of 30 feet. A layer of concrete, a foot or two thick, is spread over the bottom of the pit and on it are bedded rows of steel beams set close together. Across the middle of these beams deep steel girders are placed on which the columns are erected. The heavy weight is then spread out by the beams, girders and concrete, so as to cause a reduced uniform pressure on the soil. Cement is filled in between the beams and girders and packed around them to seal them thoroughly against moisture. Then clean earth or sand is rammed in up to the column bases and covered with the concrete of the cellar floor. In some cases the foundation loads are so numerous that nothing short of masonry peers on solid rock will safely sustain them. To accomplish this very strong airtight steel or wooden boxes with flat tops and no bottoms are set on the pier sites at ground water level and pumped full of compressed air, while men enter them and excavating the soil undermine them so they sink until they land on the rock and are filled solid with concrete to form the bases of the foundation peers. On the average the formation should have a resisting power of two tons to the square foot, dead load. By dead load is meant the weight of the steelwork, floors and walls, as distinguished from the office furniture and occupants which come under the head of living load. Some engineers take into consideration the pressure of both dead and live loads gauging the strength of the foundation, but the dead load pressure of two tons to the square foot will do for the reckoning, for as a live load only exerts a pressure of 60 pounds to the square foot it may be included in the former. The columns carry the entire weights including dead and live loads and the wind pressure into the footings, these again distributing the loads on the soil. The aim is to have an equal pressure per square foot of soil at the same time for all footings, thus ensuring an even settlement. The skeleton construction now almost wholly consists of wrought steel. At first cast iron and wrought iron were used, but it was found they corroded too quickly. There are two classes of steel construction, the cage and the skeleton. In the cage construction the frame is strengthened for wind stresses and the walls act as curtains. In the skeleton the frame carries only the vertical loads and depends upon the walls for its wind bracing. It has been found that the wind pressure is about 30 pounds for every square foot of exposed surface. The steel columns reach from the foundation to the top, riveted together by plates and may be extended to an indefinite height. In fact, there is no engineering limit to the height. The outside walls of the skyscraper vary in thickness with the height of the building and also vary in accordance with the particular kind of construction, whether cage or skeleton. If of the cage variety the walls, as has been said, act as curtains and consequently they are thinner than in the skeleton type of construction. In the latter case the walls have to resist the wind pressure unsupported by the steel frame and therefore they must be of a sufficient width. Brick and terracotta blocks are used for construction generally. Terracotta blocks are also much used in the flooring and for this purpose have several advantages over other materials. They are absolute fireproof. They weigh less per cubic foot than any other kind of fireproof flooring and they are almost soundproof. They do equally well for flat and arched floors. It is of the utmost importance that the skyscraper be absolutely fireproof from bottom to top. These great buzzing hives of industry house at one time several thousand human beings and a panic would entail a fearful calamity and, moreover, their height places the upper stories beyond reach of a water tower and the pumping engines of the street. The skyscrapers of today are as fireproof as human ingenuity and skill can make them and this is saying much. In fact, it means that they cannot burn. Of course, fires can break out in rooms and apartments in the manufacturing of chemicals or testing experiments, etc., but these are easily confined to narrow limits and readily extinguished with the apparatus at hand. Steel columns will not burn, but if exposed to heat of sufficient degree, they will warp and bend and probably collapse. Therefore, they should be protected by heat-resisting agents. Nothing can be better than terracotta and concrete for this purpose. When terracotta blocks are used, they should be at least two inches thick with an airspace running through them. Columns are also fireproofed by wrapping expanded metal or other metal lathing around them and plastering. Then a furring system is put on and another layer of metal, lathing and plastering. This, if well done, is probably safer than the layer of hollow tile. The floor beams should be entirely covered with terracotta blocks or concrete so that no part of them is left exposed. As most office trimmings are of wood, care should be taken that all electric wires are well insulated. Faulty installation of dynamos, motorists and other apparatus is frequently the cause of office fires. The lighting of a skyscraper is a most elaborate arrangement. Some of them use as many lights as would well supply a good-sized town. The Singer Building in New York has 15,000 incandescent lamps and it is safe to say the Metropolitan Life Insurance Building has more than twice this number, as the floor area of the latter is two and a half times as great. The engines and dynamos are in the basement and so fixed that their vibrations do not affect the building. As space is always limited in the basements of skyscrapers, direct connected engines and dynamos are generally installed instead of built connected and the boilers operated under a high steam pressure. Besides delivering steam to the engines, the boiler is also supplied to a variety of auxiliary pumps, as boiler feet, fire pump, blow-off, tank pump and pump for forcing water through the building. The heating arrangement of such a vast area as is covered by the floor space of a skyscraper has been a very difficult problem, but it has been solved so that the occupant of the 20th story can receive an equal degree of heat with the one on the ground floor. Both hot water and steam are utilized. Hot water heating, however, is preferable to steam as it gives a much steadier heat. The radiators are proportioned to give an average temperature of 65 degrees Fahrenheit in each room during the winter months. There are automatic regulating devices attached to the radiators, so if the temperature rises above or falls below a certain point, the steam or hot water is automatically turned on or off. Some buildings are heated by the exhaust steam from the engines, but most have boilers solely for the purpose. The sanitary system is another important feature. The supplying of water for wash stands, the dispositions of wastes and the flushing of lavatories tax all the skill of the mechanical engineer. Several of these mighty buildings call for upwards of a thousand lavatories. In considering the skyscraper we should not forget the role played by the electric elevator. Without it, these buildings would be practically useless, as far as the upper stories are concerned. The labour of stair-climbing would leave them untenanted. No one would be willing to climb ten, twenty or thirty flights and tackle a day's work after the exertion of doing so. To climb to the fiftieth story in such a manner would be well-nigh impossible or only possible by relays, and after one would arrive at the top he would be so physically exhausted that both mental and manual endeavour would be out of the question. Therefore the elevator is as necessary to the skyscraper as our doors and windows. Indeed, were it not for the introduction of the elevator, the business sections of our large cities would still consist of the five and six-story structures of our father's time, instead of the towering edifices, which now lift their heads among the clouds. Regarding less than half a century ago as an unnecessary luxury, the elevator today is an imperative necessity. Skyscrapers are equipped with both express and local elevators. The express elevators do not stop until about the tenth floor is reached. They run at a speed of about ten feet per second. There are two types of elevators in general use, one lifting the car by cables from the top and the other with a hydraulic plunger acting directly upon the bottom of the car. The former are operated either by electric motors or hydraulic cylinders and the latter by hydraulic rams, the cylinder is extending the full height of the building into the ground. America is preeminently the land of the skyscraper, but England and France to a degree are following along the same lines, though nothing is yet has been erected on the other side of the water to equal the towering triumphs of architectural art on this side. In no country in the world is space at such a premium as in New York City. Therefore, New York per se may be regarded as the true home of the tall building, although Chicago is not very much behind the metropolis in this respect. As figures are more eloquent than words in description, the following data of the two giant structures of the western world may be interesting. The Singer building at the corner of Broadway and Liberty Street, New York City, has a total height from the basement floor to the top of the flagstaff of 742 feet. The height from street to roof is 612 feet 1 inch. There are 41 stories. The weight of the steel in the entire building is 9200 tons. It has 16 elevators, 5 steam engines, 5 dynamos, 5 boilers and 28 steam pumps. The length of the steam and water piping is 5 miles. The cubical contents of the building comprise 66,950,000 cubic feet. There are 411,000 square feet of floor area or about nine and a half acres. The weight of the tower is 18,300 tons. Little danger from a collapse will be apprehended when it is learned that the columns are securely bolted and caissons which have been sunk to rock bed 80 feet below the curb. The other campanile which has excited the wonder and admiration of the world is the colossal pile known as the Metropolitan Building. This occupies the entire square or block, as we call it, from 23rd Street to 24th Street and from Madison to 4th Avenue. It is 700 feet and 3 inches above the sidewalk and has 50 stories. The main building, which has a frontage of 200 feet by 425 feet, is 10 stories in height. It is built in the early Italian Renaissance style, the materials being steel and marble. The campanile is carried up in the same style and is also of marble. It stands on a base measuring 75 by 83 feet and the architectural treatment is chased, though severe, but eminently agreeable to the stupendous proportions of the structure. The tower is quite different from that of the Singer Building. It has 12 wall and 8 interior columns connected at every fourth floor by diagonal braces. These columns carry 1,800 pounds to the linear foot. The wind pressure calculated at the rate of 30 pounds to the square foot is enormous and is provided for by deep wall girders and knee braces, which transfer the strain to the columns and to the foundation. The average cross section of the tower is 75 by 85 feet. The floor space of the entire building is 1,080,000 square feet or about 25 acres. The tower of this surpassing cloud-piercing structure can be seen for many miles from the surrounding country and from the bay it looks like a giant sentinel in white, watching the mighty city at its feet and proclaiming the ceaseless activity and progress of the western world.