MARVELS OF MODERN SCIENCE
By PAUL SEVERING
Edited by THEODORE WATERS
CHAPTER I FLYING MACHINES Early attempts at flight. The Dirigible. Prof. Langley's experiments. The Wright Brothers. Count Zeppelin. Recent aeroplane records.
CHAPTER II WIRELESS TELEGRAPHY Primitive signalling. Principles of wireless telegraphy. Ether vibrations. Wireless apparatus. The Marconi system.
CHAPTER III RADIUM Experiments of Becquerel. Work of the Curies. Discovery of Radium. Enormous energy. Various uses.
CHAPTER IV MOVING PICTURES Photographing motion. Edison's Kinetoscope. Lumiere's Cinematographe. Before the camera. The mission of the moving picture. Edison's latest triumph.
CHAPTER V SKY-SCRAPERS AND HOW THEY ARE BUILT Evolution of the sky-scraper. Construction. New York's giant buildings. Dimensions.
CHAPTER VI OCEAN PALACES Ocean greyhounds. Present day floating palaces. Regal appointments. Passenger accommodation. Food consumption. The one thousand foot boat.
CHAPTER VII WONDERFUL CREATIONS IN PLANT LIFE Mating Plants. Experiments of Burbank. What he has accomplished.
CHAPTER VIII LATEST DISCOVERIES IN ARCHAEOLOGY Prehistoric time. Earliest records. Discoveries in Bible lands. American explorations.
CHAPTER IX GREAT TUNNELS OF THE WORLD Primitive Tunnelling. Hoosac Tunnel. Croton aqueduct. Great Alpine tunnels. New York subway. McAdoo tunnels. How tunnels are built.
CHAPTER X ELECTRICITY IN THE HOUSEHOLD Electrically equipped houses. Cooking by electricity. Comforts and conveniences.
CHAPTER XI HARNESSING THE WATER-FALL Electric energy. High pressure. Transformers. Development of water-power.
CHAPTER XII WONDERFUL WAR SHIPS Dimensions, displacements, cost and description of battleships. Capacity and speed. Preparing for the future.
CHAPTER XIII A TALK ON BIG GUNS The first projectiles. Introduction of cannon High pressure guns. Machine guns. Dimensions and cost of big guns.
CHAPTER XIV MYSTERY OF THE STARS Wonders of the universe. Star Photography. The infinity of space.
CHAPTER XV CAN WE COMMUNICATE WITH OTHER WORLDS? Vastness of Nature. Star distances. Problem of communicating with Mars. The Great Beyond.
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. 'Tis 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 to-day 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. Science is ever on the march and what is new to-day will be old to-morrow. We cannot go back, we must go forward, and although we can never reach finality in aught, 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 serve the purpose for which it was written.
Early Attempts at Flight—The Dirigible—Professor Langley's Experiment—The Wright Brothers—Count Zeppelin—Recent Aeroplane Records.
It is hard to determine when men first essayed 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. Aeschylus exclaims:
"Oh, might I sit, sublime in air Where watery clouds the freezing snows prepare!"
Ariosto in his "Orlando Furioso" makes an English knight, whom he names Astolpho, 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 "Skyscrapers" 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 Vasson, a missionary at Canton, in a letter dated September 5, 1694, mentions a balloon that ascended on the occasion of the coronation of the Empress Fo-Kien 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 Dr. 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 Annonay, near Lyons 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, 110 feet in circumference and, with the frame weighed 300 pounds. It was filled with 22,000 cubic feet of vapor. It rose to a height of 6,000 feet and proceeded almost 7,000 feet, when it gently descended. France went wild over the exhibition.
The first to risk their lives in the air were M. Pilatre de Rozier and the Marquis de Arlandes, 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 Messrs. Charles and Robert, also Frenchmen, 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 Tytler in 1784. A few months later Lunardi sailed over London.
In 1836 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 Glaisher and Coxwell, two Englishmen, near Wolverhampton, on September 5, 1862. They ascended to such an elevation that both lost the power of their limbs, and had not Coxwell opened 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 Glaisher 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 M. Nadar, a Frenchman, which had a capacity of 215,000 cubic feet and required for a covering 22,000 yards of silk. It ascended from the Champ de Mars, Paris, in 1853, with fifteen passengers, all of whom came back safely.
The longest flight made in a balloon was that by Count de La Vaulx, 1193 miles in 1905.
A mammoth balloon was built in London by A. E. Gaudron. In 1908 with three other aeronauts Gaudron crossed from the Crystal Palace to the Belgian Coast at Ostend and then drifted over Northern Germany and was finally driven down by a snow storm at Mateki Derevni in Russia, having traveled 1,117 miles in 31-1/2 hours. The first attempt at constructing a dirigible balloon or airship was made by M. Giffard, a Frenchman, in 1852. The bag was spindle-shaped and 144 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 M. Gaston Tissandier constructed a dirigible in any way worthy of the name. It was operated by a motor driven by a bichromate of soda battery. The motor weighed 121 lbs. The cells held liquid enough to work for 2-1/2 hours, generating 1-1/3 horse power. The screw had two arms and was over nine feet in circumference. Tissandier made some successful flights.
The first dirigible balloon to return whence it started was that known as La France. This airship was also constructed in 1884. The designer was Commander Renard of the French Marine Corps assisted by Captain Krebs of the same service. The length of the envelope was 179 feet, its diameter 27-1/2 feet. The screw was in front instead of behind as in all others previously constructed. The motor which weighed 220-1/2 lbs. was driven by electricity and developed 8-1/2 horse power. The propeller was 24 feet in diameter and only made 46 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. M. Deutch, a Parisian millionaire, offered a prize of $20,000 for the first dirigible that would fly from the Parc d'Aerostat, 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 108 feet, the diameter 19-1/2 feet. It had a 4-cylinder petroleum motor weighing 216 lbs., which generated 20 horse power. The screw was 13 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, Parseval, Lebaudy, Baidwin and Gross were crowding one another for honors. 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 the 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 Karl Meerwein of Baden. He calculated that a man weighing 200 lbs. would require 128 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 19th 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 Lilienthal in Germany discovered the possibility of driving curved aeroplanes against the wind. Otto Lilienthal held that it was necessary to begin with "sailing" 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 100 feet he glided a distance of 700 feet and found 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 96 lbs. and generating 2-1/2 horse power. 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. His 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 Maxim 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 worldwide 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 Manly, 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 Lilienthal 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, N.C. In 1904 with a new machine they resumed experiments at their home near Dayton, O. In September of that year they succeeded in changing the course from one dead against the wind to a curved path where cross currents must be encountered, and made many circular flights. During 1906 they rested for a while from practical flight, perfecting plans for the future. In the beginning of September, 1908, Orville Wright made an aeroplane 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 Sept. 13, 1906, that Santos-Dumont made the first officially recorded European aeroplane flight, leaving the ground for a distance of 12 yards. On November 12, of same year, he remained in the air for 21 seconds and traveled a distance of 230 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 820 yards in 52-1/2 seconds. On July 6, 1908, he remained in the air for 20-1/2 minutes. On October 31, same year, in France, he flew from Chalons to Rheims, a distance of sixteen miles, in twenty minutes.
The year 1909 witnessed mighty strides in the field of aviation. Thousands of flights were made, many of which exceeded the most sanguine anticipations. On July 13, Bleriot flew from Etampes to Chevilly, 26 miles, in 44 minutes and 30 seconds, and on July 25 he made the first flight across the British Channel, 32 miles, in 37 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 21 miles, in 33 minutes and 33 seconds during the Hudson-Fulton Celebration. On November 20 Louis Paulhan, in a biplane, flew from Mourmelon to Chalons, France, and return, 37 miles in 55 minutes, rising to a height of 1000 feet.
The dirigible airship was also much in evidence during 1909, Zeppelin, especially, performing some remarkable feats. The Zeppelin V., subsequently re-numbered No. 1, of the rigid type, 446 feet long, diameter 42-1/2 feet and capacity 536,000 cubic feet, on March 29, rose to a height of 3,280, and on April 1, started with a crew of nine passengers from Frederickshafen to Munich. In a 35 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 (1910) of the old German aeronaut have put all previous records into the shade and electrified the whole world. His new passenger airship, the Deutschland, on June 22, made a 300 mile trip from Frederickshafen to Dusseldorf in 9 hours, carrying 20 passengers. This was at the rate of 33.33 miles per hour. During one hour of the journey a speed of 43-1/2 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 32 passengers, ten of whom were women, in a 100 mile trip from Dusseldorf to Essen, Dortmund and Bochum and back. At one time on this occasion while traveling with the wind the airship made a speed of 56-1/2 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 485 feet long with a total lifting power of 44,000 lbs. It has three motors which total 330 horse power and it drives at an average speed of about 33 miles an hour. A regular passenger service has been established and tickets are selling at $50.
The present year can also boast some great aeroplane records, notably by Curtiss and Hamilton in America and Farman and Paulhan in Europe. Curtiss flew from Albany to New York, a distance of 137 miles, at an average speed of 55 miles an hour and Hamilton flew from New York to Philadelphia and return. 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 return.
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 aeroplane. 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 ploughing 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 aeroplane. 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 aeroplane are planes and this doubt less arises from the word itself. However, the last syllable in aeroplane 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 aero curves arched in the rear of the front edge, thus allowing the supporting surface of the aeroplane 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 under side.
After the surfaces come the rudders in importance. It is of vital consequence that the machine be balanced by the operator. In the present method of balancing an aeroplane 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 angle at a sudden turn. To accomplish this, two methods can be employed. 1. Changing the form of the wing. 2. 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 Leon Levavasseur in France. It enabled Santos-Dumont to make his first public successful flights. Nearly all aeroplanes follow the same general principles of construction. Of course a good deal depends upon the form of aeroplane—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 writing a triplane has been introduced into the domain of American aviation by an English aeronaut. 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 Wright biplane is characterized by warping wing tips and seams of heavy construction, while the surfaces of the Herring-Curtiss 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. Farman'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 up in a sort of cockpit on the top. Bleriot sits far beneath his machine. In the latest construction of Santos-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-Curtiss, at Hammondsport, N.Y., as the Wright place at Dayton is very small and only turns out motors and experimenting machines, and cannot be called a regular factory. The Wright machines are now manufactured by a French syndicate. It is said that the Wrights 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 horse power.
The latest model of Bleriot known as No. 12 has beaten the time record of Glenn Curtiss' biplane with its 60 horse power motor. The Farman machine or the model in which he made the world's duration record in his three hour and sixteen minutes flight at Rheims, 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 twenty-five meters square, is eight meters long and seven-and-a-half meters wide, weighs 140 kilos, and has a motor which develops from 25 to 50 horse power.
The Wright machines cost $6,000. They have four cylinder motors of 30 horse power, are 12-1/2 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 aeroplane 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 1-5 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 aeroplane 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 Curtiss, made a short time ago over Lake Keuka at Hammondsport, N.Y., prove what a mighty factor would have to be reckoned with in the martial aeroplane. Curtiss without any practice at all hit a mimic battle ship fifteen times out of twenty-two shots. His experiment has convinced the military and naval authorities of this country that the aeroplane 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.
Primitive Signalling—Principles of Wireless Telegraphy—Ether Vibrations—Wireless Apparatus—The Marconi System.
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 signalling. 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 night time build fires outside their huts or kraals 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 mid-summer. 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 signalling, 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 signalling 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 no 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 tympanum 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 impalpable 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 centre, the initial point of the disturbance, until they fade altogether 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 air waves.
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 inter-stellar 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 of between 92,000,000 and 95,000,000 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 electro-magnetic disturbance in the ether. Again when we charge an insulated body with electricity we find that it attracts any light substance indicating a material disturbance in the ether. This is described as an electro-static disturbance or effect and it is upon this that wireless telegraphy depends for its operations.
The late German physicist, Dr. Heinrich Hertz, Ph.D., 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 discharge 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 projected 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 blazoning 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 transverse 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 effected 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 wave length or period.
The term electric radiation was first employed by Hertz to designate waves emitted by a Leyden 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 ninety per cent. nickel and ten per cent. 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, viz., 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 effect 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 round 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 signalled 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 but 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 their 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, Braun-Siemens of Germany and those of DeForest and Fessenden of America. The electrolytic detector with the paste between the tin blocks belongs to the system of DeForest. Besides these the names of Popoff, 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 some one intercept the messages intended for another, but this is being overcome by the adoption of a special system of wave lengths 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 two hundred 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 instrument similarly connected to earth, keep within the immediate neighborhood of the earth.
For instance up to about two hundred 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 despatches, 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; wrecks, 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 Boulogne. The distance was thirty-two 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 one hundred mile limit.
In 1900 communication was established between the Isle of Wight and the Lizard in Cornwall, a distance of two hundred miles.
Up to this time the only appliances employed were induction coils giving a ten or twenty 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 a 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 Poldhu 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 three thousand 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 21, 1902, from a station at Glace Bay, Nova Scotia, Marconi sent the first message by wireless to England announcing success to his colleagues.
The following January from Wellsfleet, Cape Cod, President Roosevelt sent a congratulatory message to King Edward. The electric waves conveying this message traveled 3,000 miles over the Atlantic following round an arc of forty-five degrees of the earth on a great circle, and were received telephonically, by the Marconi magnetic receiver at Poldhu.
Most ships are provided with syntonic receivers which are tuned to long distance transmitters, and are capable of receiving messages up to distances of 3,000 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 Ayres, has received messages from the station at Clifden, County Galway, Ireland, a distance of 5,600 miles. The best previous record was made when the United States battleship Tennessee in 1909 picked up a message from San Francisco when 4,580 miles distant.]
Experiments of Becquerel—Work of the Curies—Discovery of Radium—Enormous Energy—Various Uses.
Early in 1896 just a few months after Roentgen 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 Roentgen 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 the result of accident. Becquerel had no idea of such radiations, had never thought of their possibility.
In the early days of the Roentgen 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 then 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 again 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 not be 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 has 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, Mme. Sklodowska Curie, the wife of a French professor and physicist. Mme. 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 radio-active 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 ore of pitchblende they found not only one but three substances highly radio-active. Pitchblende or uraninite 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 sulphide, lime silica, and other bodies.
To the radio-active substance which accompanied the bismuth extracted from pitchblende the Curies gave the name Polonium. To that which accompanied barium taken from the same ore they called Radium and to the substance which was found among the rare earths of the pitchblende Debierne gave the name Actinium.
None of these elements have been isolated, that is to say, separated in a pure state from the accompanying ore. 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 Debierne she treated a decegramme of bromide of radium by electrolytic process, getting an amalgam from which was extracted the metallic radium by distillation.] All that has been obtained is some one 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 chlorin 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 1,200 pounds of pitchblende.
The second form of radium 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 radio-activity to other bodies. Any material when placed near radium becomes radio-active 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 in 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 horse power station working continuously far forty thousand years. This assertion is probably based on the fact that every corpuscle in the ether vibrates with the speed of light or about 186,000 miles a second.
It was formerly believed that the atom was the smallest sub-division 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 centre of a varied attraction of molecules, corpuscles and electrons. Had we held to the atomic theory and denied smaller sub-divisions 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 radio-active substance. The Alpha rays constitute ninety-nine per cent, 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 in 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 produced 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 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 Leyden 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 one hundred 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 a radium salt is placed in a closed vessel the radio-activity in part leaves the solution and distributes itself through the vessel, the sides of which become radio-active and luminous.
Radium acts upon the chemical constituents of glass, porcelain and paper, giving them a violet tinge, changes white phosphorous 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, in 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 when 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 two other elements found in the ores of uranium and thorium, viz., polonium and actinium. Polonium, so-called, in honor of the native land of Mme. Curie, is just as active as radium when first extracted from the pitchblende but its energy soon lessens and finally it becomes inert, hence there has been little experimenting or investigation. The same may be said of actinium.
The process of obtaining radium from pitchblende is most tedious and laborious and requires much patience. The residue of the pitchblende from which uranium has been extracted by fusion with sodium carbonate and solution in dilute sulphuric 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 sulphuric acid. The insoluble barium and radium sulphates, 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 pitchblende 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 $200 a day. If purchased the price for this amount would be $4,000.
Photographing Motion—Edison's Kinetoscope—Lumiere's Cinematographe—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 text books 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 any way 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 theatre. It is estimated that at the present time in America there are upwards of 20,000 moving picture shows patronized daily by almost ten million people. It is doubtful if the theatre attendance at the best day of the winter season reaches five 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 Muybridge, 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 gelatine 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. Muybridge 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 twenty or thirty 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 ten 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.
Muybridge 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 disk about 18 inches in diameter near its circumference. This disk 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 disk 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 Muybridge had accomplished in the line of motion pictures of animals almost ten years previously. Edison, however, did not employ a battery of cameras as Muybridge 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 the 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 fifty 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 twenty to twenty-five 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 Lumiere, came forward with his Cinematographe 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 pictures machines we have had the vitascope, vitagraph, magniscope, mutoscope, panoramagraph, theatograph and scores of others all derived from the two Greek roots grapho I write and scopeo I view.
The vitascope is the principal name now in use for moving 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 life-like 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 blackguard 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 the 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. Paste diamonds sparkle in necklaces, crowns and tiaras, seeming to rival the scintillations of the Kohinoor.
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 the history and best traditions of our country.
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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 Tettrazini 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 propriae personae.
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 twenty 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.
SKY-SCRAPERS AND HOW THEY ARE BUILT
Evolution of the Sky-scraper—Construction—New York's Giant Buildings—Dimensions.
The sky-scraper 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 fifty stories towering up to a height of seven hundred feet and three inches, has been the crowning achievement of architectural art, the highest building yet erected by man.
How is it possible to erect such building—how is it possible to erect a sky-scraper 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 sky-scrapers.
To attempt to build a sky-scraper without a suitable foundation would be tantamount 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 frame work 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 sky-scrapers 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 one hundred 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 thirty 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 thus 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 piers 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 piers.
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 2 tons to the square foot will do for the reckoning, for as a live load only exerts a pressure of 60 lbs. to the square foot it may be included in the former.