"Around 1881-82 I had several solicitors attending to different classes of work. One of these did me a most serious injury. It was during the time that I was developing my electric-lighting system, and I was working and thinking very hard in order to cover all the numerous parts, in order that it would be complete in every detail. I filed a great many applications for patents at that time, but there were seventy-eight of the inventions I made in that period that were entirely lost to me and my company by reason of the dishonesty of this patent solicitor. Specifications had been drawn, and I had signed and sworn to the application for patents for these seventy-eight inventions, and naturally I supposed they had been filed in the regular way.
"As time passed I was looking for some action of the Patent Office, as usual, but none came. I thought it very strange, but had no suspicions until I began to see my inventions recorded in the Patent Office Gazette as being patented by others. Of course I ordered an investigation, and found that the patent solicitor had drawn from the company the fees for filing all these applications, but had never filed them. All the papers had disappeared, however, and what he had evidently done was to sell them to others, who had signed new applications and proceeded to take out patents themselves on my inventions. I afterward found that he had been previously mixed up with a somewhat similar crooked job in connection with telephone patents.
"I am free to confess that the loss of these seventy-eight inventions has left a sore spot in me that has never healed. They were important, useful, and valuable, and represented a whole lot of tremendous work and mental effort, and I had had a feeling of pride in having overcome through them a great many serious obstacles, One of these inventions covered the multipolar dynamo. It was an elaborated form of the type covered by my patent No. 219,393 which had a ring armature. I modified and improved on this form and had a number of pole pieces placed all around the ring, with a modified form of armature winding. I built one of these machines and ran it successfully in our early days at the Goerck Street shop.
"It is of no practical use to mention the man's name. I believe he is dead, but he may have left a family. The occurrence is a matter of the old Edison Company's records."
It will be seen from an examination of the list of patents in the Appendix that Mr. Edison has continued year after year adding to his contributions to the art of electric lighting, and in the last twenty-eight years—1880-1908—has taken out no fewer than three hundred and seventy-five patents in this branch of industry alone. These patents may be roughly tabulated as follows:
Incandescent lamps and their manufacture....................149
Distributing systems and their control and regulation....... 77
Dynamo-electric machines and accessories....................106
Minor parts, such as sockets, switches, safety catches,
meters, underground conductors and parts, etc............... 43
Quite naturally most of these patents cover inventions that are in the nature of improvements or based upon devices which he had already created; but there are a number that relate to inventions absolutely fundamental and original in their nature. Some of these have already been alluded to; but among the others there is one which is worthy of special mention in connection with the present consideration of a complete system. This is patent No. 274,290, applied for November 27, 1882, and is known as the "Three-wire" patent. It is described more fully in the Appendix.
The great importance of the "Feeder" and "Three-wire" inventions will be apparent when it is realized that without them it is a question whether electric light could be sold to compete with low-priced gas, on account of the large investment in conductors that would be necessary. If a large city area were to be lighted from a central station by means of copper conductors running directly therefrom to all parts of the district, it would be necessary to install large conductors, or suffer such a drop of pressure at the ends most remote from the station as to cause the lights there to burn with a noticeable diminution of candle-power. The Feeder invention overcame this trouble, and made it possible to use conductors ONLY ONE-EIGHTH THE SIZE that would otherwise have been necessary to produce the same results.
A still further economy in cost of conductors was effected by the "Three-wire" invention, by the use of which the already diminished conductors could be still further reduced TO ONE-THIRD of this smaller size, and at the same time allow of the successful operation of the station with far better results than if it were operated exactly as at first conceived. The Feeder and Three-wire systems are at this day used in all parts of the world, not only in central-station work, but in the installation and operation of isolated electric-light plants in large buildings. No sensible or efficient station manager or electric contractor would ever think of an installation made upon any other plan. Thus Mr. Edison's early conceptions of the necessities of a complete system, one of them made even in advance of practice, have stood firm, unimproved, and unchanged during the past twenty-eight years, a period of time which has witnessed more wonderful and rapid progress in electrical science and art than has been known during any similar art or period of time since the world began.
It must be remembered that the complete system in all its parts is not comprised in the few of Mr. Edison's patents, of which specific mention is here made. In order to comprehend the magnitude and extent of his work and the quality of his genius, it is necessary to examine minutely the list of patents issued for the various elements which go to make up such a system. To attempt any relation in detail of the conception and working-out of each part or element; to enter into any description of the almost innumerable experiments and investigations that were made would entail the writing of several volumes, for Mr. Edison's close-written note-books covering these subjects number nearly two hundred.