Boys' Life of Edison - W. H. Meadowcroft

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 dispatcher'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 I886 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 notebooks, 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.
  • A "dead-beat" galvanometer without coils or magnetic needle.
  • The odoroscope, for measuring odors; preserving fruit in vacuo;  making plate glass; drawing wire.
  • Metallurgical processes for treatment of nickel, gold, and copper ores.

From first to last Edison has filed in the United States Patent Office more than fourteen hundred applications for patents. Besides, he filed some one hundred and twenty caveats, embracing not less than fifteen hundred additional inventions. The caveat has now been abolished in patent-office practice, but such a document could formerly be filed by an inventor to obtain a partial protection for a year while completing his invention. As an example of Edison's fertility and the endless variety of subjects engaging his attention the following list of matters covered by one of his caveats is given. All his caveats are not quite so full of "plums," but this is certainly a wonder:

Forty-one distinct inventions relating to the phonograph, covering various forms of recorders, arrangement of parts, making of records, shaving tool, adjustments, etc.

  • Eight forms of electric lamps using infusible earthy oxides and brought to high incandescence in vacuo  by high potential current of several thousand volts; same character as impingement of X-rays on object in bulb.
  • A loud-speaking telephone with quartz cylinder and beam of ultraviolet light.
  • Four forms of arc-light with special carbons. A thermostatic motor.
  • A device for sealing together the inside part and bulb of an incandescent lamp mechanically.
  • Regulators for dynamos and motors. Three devices for utilizing vibrations beyond the ultraviolet.
  • A great variety of methods for coating incandescent lamp filaments with silicon, titanium, chromium, osmium, boron, etc.
  • Several methods of making porous filaments.
  • Several methods of making squirted filaments of a variety of materials, of which about thirty are specified.
  • Seventeen different methods and devices for separating magnetic ores.
  • A continuously operative primary battery.
  • A musical instrument operating one of Helmholtz's artificial larynxes.
  • A siren worked by explosion of small quantities of oxygen and hydrogen mixed.
  • Three other sirens made to give vocal sounds or articulate speech.
  • A device for projecting sound-waves to a distance without spreading, and in a straight line, on the principle of smoke-rings.
  • A device for continuously indicating on a galvanometer the depths of the ocean.
  • A method of preventing in a great measure friction of water against the hull of a ship and incidentally preventing fouling by barnacles.
  • A telephone receiver whereby the vibrations of the diaphragm are considerably amplified.
  • Two methods of "space" telegraphy at sea.
  • An improved and extended string telephone.
  • Devices and method of talking through water for a considerable distance.
  • An audiphone for deaf people.
  • Sound-bridge for measuring resistance of tubes and other materials for conveying sound.
  • A method of testing a magnet to ascertain the existence of flaws in the iron or steel composing the same.
  • Method of distilling liquids by incandescent conductor immersed in the liquid.
  • Method of obtaining electricity direct from coal.
  • An engine operated by steam produced by the hydration and dehydration of metallic salts.
  • Device and method of telegraphing photo-graphically.
  • Carbon crucible kept brilliantly incandescent by current in vacuo for obtaining reaction with refractory metals.
  • Device for examining combinations of odors and their changes by rotation at different speeds.

It must be borne in mind that the above and hundreds of others are not merely ideas put in writing, but represent actual inventions upon which Edison worked and experimented. In many cases the experiments ran into the thousands, requiring months for their performance.

To describe Edison's mere ideas and suggestions for future work would of itself fill a volume. These are written in his own handwriting in a number of large record-books which he has shown to the writer. Judging from a hasty inspection, there is enough material in these books to occupy the lifetime of several persons.

The immense range of Edison's mind and activities cannot well be described in cold print, but can only be adequately comprehended by those who have been closely associated with him for a length of time, and who have had opportunity of studying his voluminous records.