Part 13

One of the earliest efforts in this direction was made before Edison was born, and shown by a toy called the Zoetrope, or "Wheel of Life." A number of figures showing fractional parts of the motion of an object--such, for instance, as a boy skating--were boldly drawn in silhouette on a strip of paper. This paper was put inside an open cylinder having small openings around its circumference. The cylinder was mounted on a pivot, and, when revolved, the figures on the paper seemed to be in motion when viewed through the openings.

The success of this and similar toys, as well as of modern motion-pictures, depends upon a phenomenon known as the "persistence of vision." This means that if an object be presented to the vision for a moment and then withdrawn, the image of that object will remain impressed on the retina of the eye for a period of one-tenth to one-seventh of a second.

If, for instance, a bright light be moved rapidly up and down in front of the eye in a dark room it appears not as a single light, but as a line of fire, because there is not time for the eye to lose the image of the light between the rapid phases of its motion. For the same reason, if a number of pictures exactly alike were rapidly presented to the eye in succession it would seem as if a single picture were being viewed.

Thus, if a number of photographs, say at the rate of fifteen per second, be taken of a moving object, each successive photograph will show a fraction of the movements. Now if these photographs be thrown on a screen in the same order and at the same rate at which they were taken the movements of the object would apparently again take place, because the eye does not have time to lose the image of one fractional movement before the next follows.

One of the earliest suggestions of reproducing animate motion was made by a Frenchman named Ducos about 1864. He was followed by others, but they were all handicapped by the fact that dry-plates and sensitized film were entirely unknown, and the wet plates then used were entirely out of the question for the development of a practical commercial scheme.

The first serious attempt to secure photographs of objects in motion was made in 1878 by Edward Muybridge. At this time very rapid wet-plates were known. By arranging a line of cameras along a track and causing a horse in trotting past them to strike wires or strings attached to the shutters, the plates were exposed and a series of clear instantaneous photographs of the horse in motion was obtained.

Positive prints were made which were mounted in a modified form of Zoetrope and projected upon a screen. The horse in motion was thus reproduced, but, differing from the motion-pictures of to-day, always remained in the center of the screen in violent movement and making no progress.

Early in the 'eighties dry-plates were introduced, and other experimenters took up the work, but they were handicapped by the fact that plates were heavy and only a limited number could be used. This difficulty may be easily understood when it is realized that a modern motion-picture reel lasting fifteen minutes comprises about sixteen thousand separate and distinct photographs. The impossibility of manipulating this large number of glass plates to show one motion-picture play will be seen at once.

This was the condition of the art when Edison entered upon the work. He himself says, "In the year 1887 idea occurred to me that it was possible to devise an instrument which should do for the eye what the phonograph does for the ear, and that by a combination of the two all motion and sound could be recorded and reproduced simultaneously."

Two very serious difficulties lay in the way, however--first, a sensitive surface of such form and weight as could be successively brought into position and exposed at a very high rate; and, secondly, the making of a camera capable of so taking the pictures. Edison proved equal to the occasion, and, after an immense amount of work and experiment, continuing over a long period of time, succeeded in producing apparatus that made modern motion-pictures possible.

In his earliest experiments a cylinder about the size of a phonograph record was used. It was coated with a highly sensitized surface, and microscopic photographs, arranged spirally, were taken upon it. Positive prints were made in the same way, and viewed through a magnifying-glass. Various forms of this apparatus were made, but all were open to serious objections, the chief trouble being with the photographic emulsion.

During this experimental period the kodak film was being developed by the Eastman Kodak Company, under the direction of Mr. George Eastman. Edison recognized that in this product there lay the solution of that part of the problem. At first the film was not just what he required, but the Eastman Company after a time developed and produced the highly sensitized surface that Edison sought.

It then remained to devise a camera by means of which from twenty to forty pictures per second could be taken. Every user of a film camera can appreciate the difficulty of the problem. A long roll of film must pass steadily behind the lens. At every inch it must be stopped, the shutter opened for the exposure, and then closed again. The film must be advanced say an inch, and these operations repeated twenty to forty times a second throughout, perhaps, a thousand feet of film.

Who but an Edison would assume that such a device could be made, and with such exactness that each picture should coincide with the others? After much experiment, however, he finally accomplished it, and in the summer of 1889 the first modern motion-picture camera was made. From that day to this the Edison camera has been the accepted standard for securing pictures of objects in motion.

The earliest form of exhibiting apparatus was known as the kinetoscope. It was a machine in which a positive print from the negative roll of film obtained in the camera was exhibited directly to the eyes through a peep-hole. About 1895 the pictures were first shown through a modified form of magic lantern, and have so continued to this day. The industry has grown very rapidly, and for a long time the principal American manufacturers of motion-pictures paid a royalty to Edison under his basic patents.

The pictures made in the earliest days of the art were simple and amusing, such as Fred Ott's sneeze, Carmencita dancing, Italians and their performing bears, fencing, trapeze stunts, horsemanship, blacksmithing, and so on. No attempt was made to portray a story or play. The "boys" at the laboratory laugh when they tell of a local bruiser who agreed to box a few rounds with "Jim" Corbett in front of the camera. When this local "sparring partner" came to face Corbett he was so paralyzed with terror he could hardly move.

These early pictures were made in the yard of Edison's laboratory at Orange, in a studio called the "Black Maria." It was made of wood, painted black inside and out, and could be swung around to face the sunlight, which was admitted by a movable part of the roof.

This is all very different in these modern days. The studios in which interior motion-pictures are made are expensive and pretentious affairs. An immense building of glass, with all the properties and stage settings of a regular theater, are required. Of course many of the plays are produced out of doors, in portions of the country suited to the story.

All the companies producing motion-pictures employ regular stock companies of actors and actresses, selected especially for their skill in pantomime, although, as may be suspected, in the actual taking of the pictures they are required to carry on an animated dialogue as if performing on the real stage. This adds to the smoothness and perfection of the performance.

Motion-picture plays are produced under the direction of skilled stage-managers who must be specially trained for this particular business. Their work is far from being easy, for an act in a picture-play must be exact and free from mistakes, and must take place in a very short time. For instance, an act in such a play may take less than five minutes to perform, but it must be carefully rehearsed for several weeks beforehand.

There is plenty of scope for patience and ingenuity in taking motion-picture plays. If trained children or animals are required they must be found or trained; and all the resources of trick and stop photography are called upon from time to time as the occasion requires.

Edison has always held to his idea of a combination of the phonograph and motion-picture. Some time ago he said, "I believe that in coming years, by my own work and that of Dickson, Muybridge, Marey, and others who will doubtless enter the field, grand opera can be given at the Metropolitan Opera House in New York without any material change from the original, and with artists and musicians long since dead."

This prediction has been partly fulfilled, for Edison's successful talking motion-pictures marked the beginning of the "talkies" which are flourishing to-day.

XXI

EDISON INVENTS A NEW STORAGE BATTERY

Many an invention has been made as the result of some happy thought or inspiration, but most inventions are made by men working along certain lines, who set out to accomplish a desired result. It is rarely, however, that man starts out deliberately, as Edison did, to invent an entirely new type of such an intricate device as a storage battery, with only a vague starting point.

Previous to Edison's work the only type of storage battery known was the one in which lead plates and sulphuric acid were employed. He had always realized the value of a storage battery as such, but never believed that the lead-acid type could fulfil all expectations because of its weight and incurable defects.

About the time that he closed the magnetic iron ore concentrating plant (in the beginning of the present century) Edison remarked to Mr. R. H. Beach, then of the General Electric Company: "Beach, I don't think nature would be so unkind as to withhold the secret of a _good_ storage battery if a real earnest hunt for it is made. I'm going to hunt." And before starting he determined to avoid lead and sulphuric acid.

Edison is frequently asked what he considers to be the secret of achievement. He always replies, "Hard work, based on hard thinking." He has consistently lived up to this prescription to the utmost.

Of all his inventions it is doubtful whether any one of them has called forth more original thought, work, perseverance, ingenuity, and monumental patience than the one we are now dealing with. One of his associates who has been through the many years of the storage-battery drudgery with him said: "If Edison's experiments, investigations, and work on this storage battery were all that he had ever done, I should say that he was not only a notable inventor, but also a great man. It is almost impossible to appreciate the enormous difficulties that have been overcome."

From a beginning which was made practically in the dark, it was not until he had completed more than ten thousand experiments that he obtained any positive results whatever. Month after month of constant work by day and night had not broken down Edison's faith in success, and the failure of an experiment simply meant that he had found something else that would _not_ do, thus bringing him nearer the possible goal.

After this immense amount of preliminary work he had obtained promising results in a series of reactions between nickel and iron, and was then all afire to push ahead. He therefore established a chemical plant at Silver Lake, New Jersey, and, gathering around him a corps of mechanics, chemists, machinists, and experimenters, settled down to one of his characteristic struggles for supremacy. To some extent it was a revival of the old Menlo Park days and nights.

The group that took part in these early years of Edison's arduous labors included his old-time assistant, Fred Ott, together with his chemist, J. W. Aylsworth, as well as E. J. Ross, Jr.; W. E. Holland, and Ralph Arbogast, and a little later W. G. Bee, all of whom grew up with the battery and devoted their energies to its commercial development.

One of these workers, relating the strenuous experiences of these few years, says: "It was hard work and long hours, but still there were some things that made life pleasant. One of them was the supper-hour we enjoyed when we worked nights. Mr. Edison would have supper sent in about midnight, and we all sat down together, including himself. Work was forgotten for the time, and all hands were ready for fun. I have very pleasant recollections of Mr. Edison at these times. He would always relax and help to make a good time, and on some occasions I have seen him fairly overflow with animal spirits, just like a boy let out of school. He was very fond of telling and hearing stories, and always appreciated a joke. After the supper-hour was over, however, he again became the serious, energetic inventor, deeply immersed in the work in hand."

Another interesting and amusing reminiscence of this period of activity has been told by another of the family of experimenters: "Sometimes when Mr. Edison had been working long hours he would want to have a short sleep. It was one of the funniest things I ever witnessed to see him crawl into an ordinary roll-top desk and curl up and take a nap. If there was a sight that was still more funny, it was to see him turn over on his other side, all the time remaining in the desk. He would use several volumes of _Watts' Dictionary of Chemistry_ for a pillow, and we fellows used to say that he absorbed the contents during his sleep, judging from the flow of new ideas he had on waking."

Such incidents as these serve merely to illustrate the lighter moments that relieved the severe and arduous labors of the strenuous five years of the early storage-battery work of Edison and his associates. Difficulties there were a-plenty, but these are what Edison usually thrives on. As another coworker of this period says: "Edison seemed pleased when he used to run up against a serious difficulty. It would seem to stiffen his backbone and make him more prolific of new ideas. For a time I thought I was foolish to imagine such a thing, but I could never get away from the impression that he really appeared happy when he ran up against a serious snag."

It would be out of the question in a book of this kind to follow Edison's trail in detail through the innumerable twists and turns of his experimentation on the storage battery, for they would fill a big volume. The reader may imagine how extensive they were from the reply of one of his laboratory assistants, who, when asked how many experiments were made on the storage battery since the year 1900, replied: "Goodness only knows! We used to number our experiments consecutively from one to ten thousand, and when we got up to ten thousand we turned back to one and ran up to ten thousand again, and so on. We ran through several series--I don't know how many, and have lost track of them now, but it was not far from fifty thousand."

The mechanical problems in devising this battery were numerous and intricate, but the greatest difficulty that Edison had to overcome was the proper preparation of nickel hydrate for the positive and iron oxide for the negative plate. He found that comparatively little was known by manufacturing chemists about these compounds. Hence it became necessary for him to establish his own chemical works and put them in charge of men specially trained by himself.

After an intense struggle with these problems, lasting over several years, the storage battery was at length completed and put on the market. The public was ready for it and there was a rapid sale.

Continuous tests of the battery were carried on at the laboratory, as well as practical and heavy tests in automobiles, which were kept running constantly over all kinds of roads under Edison's directions. After these tests had been going on for some time the results showed that occasionally a cell here and there would fall short in capacity.

This did not suit Edison. He was determined to make his storage battery a complete success, and after careful thought decided to shut down until he had overcome the trouble. The customers were satisfied and wanted to buy more batteries, but he was not satisfied and would sell no more until he had made the battery perfect.

He therefore shut down the factory and went to experimenting once more. The old strenuous struggle set in and continued nearly three years before he was satisfied beyond doubt that the battery was right. In the early summer of 1909 Edison once more started to manufacture and sell the batteries, and has since that time continued to supply them as quickly as they are made. At the present writing the factory is running day and night in attempting to keep up with orders.

One of the principal troubles of the earlier cells was a lack of conductivity between the nickel hydrate and the metal tube in which it was contained. Edison had used graphite to obtain this conductivity, but this material proved to be uncertain in some cases. After a long course of study and experiment he solved this problem in a satisfactory manner by using flakes of pure nickel, which he obtained by a most fascinating and ingenious process.

A metallic cylinder is electroplated with alternate layers of copper and nickel, one hundred of each. The combined sheet, which is only as thick as a visiting-card, is stripped off the cylinder and cut into tiny squares of about one-sixteenth of an inch each. These squares are put into a bath which dissolves out the copper. This releases the layers of nickel, so that each of these squares becomes one hundred tiny sheets, or flakes, of pure metallic nickel, so thin and light that when they are dried they will float in the air. These flakes are automatically pressed into the positive tubes with the nickel hydrate in an ingenious machine which had to be specially invented for the purpose.

Not only was this machine specially invented, but it was necessary to invent and design practically all the other machinery that it was necessary to use in manufacturing the battery. Thus, we see that in this, as in many other of Edison's inventions, it is not only the thing itself that has been invented, but also the special machinery and tools to make it.

The principal use that Edison has had in mind for his storage battery is the transportation of freight and passengers by truck, automobile, and street-car. Although at the time of writing this book the improved battery has been on the market a little over two years, great strides have been made in carrying his ideas into effect.

The number of trucks and automobiles using Edison's storage battery already run into the thousands, with more orders than can be immediately filled.

XXII

EDISON'S MISCELLANEOUS INVENTIONS

Thus far the history of Edison's career has fallen naturally into a series of chapters each aiming to describe a group of inventions in the development of some art. This plan has been helpful to the writer and probably useful to the reader.

It happens, however, that the process has left a vast mass of discovery and invention untouched, and it is now proposed to make brief mention of a few of the hundreds of things that have occupied Edison's attention from time to time.

Beginning with telegraphy, we find that Edison did some work on wireless transmission. He says: "I perfected a system of train telegraphy between stations and trains in motion, whereby messages could be sent from the moving train to the central office; and this was the forerunner of wireless telegraphy. This system was used for a number of years on the Lehigh Valley Railroad on their construction trains. The electric wave passed from a piece of metal on top of the car across the air to the telegraph wires, and then proceeded to the despatcher's office. In my first experiments with this system I tried it on the Staten Island Railroad and employed an operator named King to do the experimenting. He reported results every day, and received instructions by mail; but for some reason he could send messages all right when the train went in one direction, but could not make it go in the contrary direction. I made suggestions of every kind to get around this phenomenon. Finally I telegraphed King to find out if he had any suggestions himself, and I received a reply that the only way he could propose to get around the difficulty was to put the island on a pivot so it could be turned around. I found the trouble finally, and the practical introduction on the Lehigh Valley road was the result. The system was sold to a very wealthy man, and he would never sell any rights or answer letters. He became a spiritualist subsequently, which probably explains it."

The earlier experiments with wireless telegraphy were made at Menlo Park during the first days of the electric light, and it was not until 1886 that Edison had time to spare to put the system into actual use. At that time Ezra T. Gilliland and Lucius J. Phelps, who had experimented on the same lines, became associated with him in the work.

Although the space between the train and the pole line was not more than fifty feet, Edison had succeeded at Menlo Park in transmitting messages through the air at a distance of five hundred and eighty feet. Speaking of this and of his other experiments with induction telegraphy by means of kites, he said, recently: "We only transmitted about two and one-half miles through the kites. What has always puzzled me since is that I did not think of using the results of my experiments on 'etheric force' that I made in 1875. I have never been able to understand how I came to overlook them. If I had made use of my own work I should have had long-distance wireless telegraphy."

These experiments of 1875, as recorded in Edison's famous note-books, show that in that year he detected and studied some then unknown and curious phenomena which made him think he was on the trail of a new force. His representative, Mr. Batchelor, showed these experiments with Edison's apparatus, including the "dark box," at the Paris Exposition in 1881. Without knowing it, for he was far in advance of the time, Edison had really entered upon the path of long-distance wireless telegraphy, as was proven later when the magnificent work of Hertz was published.

When Roentgen made the discovery of the X-ray in 1895 Edison took up experimentation with it on a large scale. He made the first fluoroscope, using tungstate of calcium for the screen. In order to find other fluorescent substances he set four men to work and thus collected upward of eight thousand different crystals of various chemical combinations, of which about eighteen hundred would fluoresce to the X-ray. He also invented a new lamp for giving light by means of these fluorescent crystals fused to the inside of the glass. Some of these lamps were made and used for a time, but he gave up the idea when the dangerous nature of the X-ray became known.

It would be possible to go on and describe in brief detail many more of the hundreds of Edison's miscellaneous inventions, but the limits of our space will not permit more than the mere mention of a _few_, simply to illustrate the wide range of his ideas and work. For instance:

A dry process of separating placer gold; the rapid disposal of heavy snows in cities.

Experiments on flying machines with an engine operated by explosions of guncotton.

The joint invention, with M. W. Scott Sims, of a dirigible submarine torpedo operated by electricity.

Pyromagnetic generators for generating electricity directly from the combustion of coal.

Pyromagnetic motors operated by alternate heating and cooling.

A magnetic bridge for testing the magnetic qualities of iron.