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.

From one of the preceding items it will be noted that even in the eighties Edison perceived much advantage to be gained in the line of economy by the use of lamp filaments employing refractory metals in their construction. From another caveat, filed in 1889, we extract the following, which shows that he realized the value of tungsten also for this purpose. "Filaments of carbon placed in a combustion tube with a little chloride ammonium. Chloride tungsten or t.i.tanium pa.s.sed through hot tube, depositing a film of metal on the carbon; or filaments of zirconia oxide, or alumina or magnesia, thoria or other infusible oxides mixed or separate, and obtained by moistening and squirting through a die, are thus coated with above metals and used for incandescent lamps.

Osmium from a volatile compound of same thus deposited makes a filament as good as carbon when in vacuo."

In 1888, long before there arose the actual necessity of duplicating phonograph records so as to produce replicas in great numbers, Edison described in one of his caveats a method and process much similar to the one which was put into practice by him in later years. In the same caveat he describes an invention whereby the power to indent on a phonograph cylinder, instead of coming directly from the voice, is caused by power derived from the rotation or movement of the phonogram surface itself. He did not, however, follow up this invention and put it into practice. Some twenty years later it was independently invented and patented by another inventor. A further instance of this kind is a method of telegraphy at sea by means of a diaphragm in a closed port-hole flush with the side of the vessel, and actuated by a steam-whistle which is controlled by a lever, similarly to a Morse key.

A receiving diaphragm is placed in another and near-by chamber, which is provided with very sensitive stethoscopic ear-pieces, by which the Morse characters sent from another vessel may be received. This was also invented later by another inventor, and is in use to-day, but will naturally be rivalled by wireless telegraphy. Still another instance is seen in one of Edison's caveats, where he describes a method of distilling liquids by means of internally applied heat through electric conductors. Although Edison did not follow up the idea and take out a patent, this system of distillation was later hit upon by others and is in use at the present time.

In the foregoing pages of this chapter the authors have endeavored to present very briefly a sketchy notion of the astounding range of Edison's practical ideas, but they feel a sense of impotence in being unable to deal adequately with the subject in the s.p.a.ce that can be devoted to it. To those who, like the authors, have had the privilege of examining the voluminous records which show the flights of his imagination, there comes a feeling of utter inadequacy to convey to others the full extent of the story they reveal.

The few specific instances above related, although not representing a t.i.the of Edison's work, will probably be sufficient to enable the reader to appreciate to some extent his great wealth of ideas and fertility of imagination, and also to realize that this imagination is not only intensely practical, but that it works prophetically along lines of natural progress.

CHAPTER XXIV

EDISON'S METHOD IN INVENTING

WHILE the world's progress depends largely upon their ingenuity, inventors are not usually persons who have adopted invention as a distinct profession, but, generally speaking, are otherwise engaged in various walks of life. By reason of more or less inherent native genius they either make improvements along lines of present occupation, or else evolve new methods and means of accomplishing results in fields for which they may have personal predilections.

Now and then, however, there arises a man so greatly endowed with natural powers and originality that the creative faculty within him is too strong to endure the humdrum routine of affairs, and manifests itself in a life devoted entirely to the evolution of methods and devices calculated to further the world's welfare. In other words, he becomes an inventor by profession. Such a man is Edison. Notwithstanding the fact that nearly forty years ago (not a great while after he had emerged from the ranks of peripatetic telegraph operators) he was the owner of a large and profitable business as a manufacturer of the telegraphic apparatus invented by him, the call of his nature was too strong to allow of profits being laid away in the bank to acc.u.mulate. As he himself has said, he has "too sanguine a temperament to allow money to stay in solitary confinement." Hence, all superfluous cash was devoted to experimentation. In the course of years he grew more and more impatient of the shackles that bound him to business routine, and, realizing the powers within him, he drew away gradually from purely manufacturing occupations, determining deliberately to devote his life to inventive work, and to depend upon its results as a means of subsistence.

All persons who make inventions will necessarily be more or less original in character, but to the man who chooses to become an inventor by profession must be conceded a mind more than ordinarily replete with virility and originality. That these qualities in Edison are superabundant is well known to all who have worked with him, and, indeed, are apparent to every one from his multiplied achievements within the period of one generation.

If one were allowed only two words with which to describe Edison, it is doubtful whether a close examination of the entire dictionary would disclose any others more suitable than "experimenter--inventor." These would express the overruling characteristics of his eventful career. It is as an "inventor" that he sets himself down in the membership list of the American Inst.i.tute of Electrical Engineers. To attempt the strict placing of these words in relation to each other (except alphabetically) would be equal to an endeavor to solve the old problem as to which came first, the egg or the chicken; for although all his inventions have been evolved through experiment, many of his notable experiments have called forth the exercise of highly inventive faculties in their very inception. Investigation and experiment have been a consuming pa.s.sion, an impelling force from within, as it were, from his petticoat days when he collected goose-eggs and tried to hatch them out by sitting over them himself. One might be inclined to dismiss this trivial incident smilingly, as a mere childish, thoughtless prank, had not subsequent development as a child, boy, and man revealed a born investigator with original reasoning powers that, disdaining crooks and bends, always aimed at the centre, and, like the flight of the bee, were accurate and direct.

It is not surprising, therefore, that a man of this kind should exhibit a ceaseless, absorbing desire for knowledge, and an apparently uncontrollable tendency to experiment on every possible occasion, even though his last cent were spent in thus satisfying the insatiate cravings of an inquiring mind.

During Edison's immature years, when he was flitting about from place to place as a telegraph operator, his experimentation was of a desultory, hand-to-mouth character, although it was always notable for originality, as expressed in a number of minor useful devices produced during this period. Small wonder, then, that at the end of these wanderings, when he had found a place to "rest the sole of his foot," he established a laboratory in which to carry on his researches in a more methodical and practical manner. In this was the beginning of the work which has since made such a profound impression on contemporary life.

There is nothing of the helter-skelter, slap-dash style in Edison's experiments. Although all the laboratory experimenters agree in the opinion that he "tries everything," it is not merely the mixing of a little of this, some of that, and a few drops of the other, in the HOPE that SOMETHING will come of it. Nor is the spirit of the laboratory work represented in the following dialogue overheard between two alleged carpenters picked up at random to help on a hurry job.

"How near does she fit, Mike?"

"About an inch."

"Nail her!"

A most casual examination of any of the laboratory records will reveal evidence of the minutest exact.i.tude insisted on in the conduct of experiments, irrespective of the length of time they occupied. Edison's instructions, always clear cut and direct, followed by his keen oversight, admit of nothing less than implicit observance in all details, no matter where they may lead, and impel to the utmost minuteness and accuracy.

To some extent there has been a popular notion that many of Edison's successes have been due to mere dumb fool luck--to blind, fortuitous "happenings." Nothing could be further from the truth, for, on the contrary, it is owing almost entirely to the comprehensive scope of his knowledge, the breadth of his conception, the daring originality of his methods, and minuteness and extent of experiment, combined with unwavering pertinacity, that new arts have been created and additions made to others already in existence. Indeed, without this tireless minutiae, and methodical, searching spirit, it would have been practically impossible to have produced many of the most important of these inventions.

Needless to say, mastery of its literature is regarded by him as a most important preliminary in taking up any line of investigation. What others may have done, bearing directly or collaterally on the subject, in print, is carefully considered and sifted to the point of exhaustion.

Not that he takes it for granted that the conclusions are correct, for he frequently obtains vastly different results by repeating in his own way experiments made by others as detailed in books.

"Edison can travel along a well-used road and still find virgin soil,"

remarked recently one of his most practical experimenters, who had been working along a certain line without attaining the desired result. "He wanted to get a particular compound having definite qualities, and I had tried in all sorts of ways to produce it but with only partial success.

He was confident that it could be done, and said he would try it himself. In doing so he followed the same path in which I had travelled, but, by making an undreamed-of change in one of the operations, succeeded in producing a compound that virtually came up to his specifications. It is not the only time I have known this sort of thing to happen."

In speaking of Edison's method of experimenting, another of his laboratory staff says: "He is never hindered by theory, but resorts to actual experiment for proof. For instance, when he conceived the idea of pouring a complete concrete house it was universally held that it would be impossible because the pieces of stone in the mixture would not rise to the level of the pouring-point, but would gravitate to a lower plane in the soft cement. This, however, did not hinder him from making a series of experiments which resulted in an invention that proved conclusively the contrary."

Having conceived some new idea and read everything obtainable relating to the subject in general, Edison's fertility of resource and originality come into play. Taking one of the laboratory note-books, he will write in it a memorandum of the experiments to be tried, ill.u.s.trated, if necessary, by sketches. This book is then pa.s.sed on to that member of the experimental staff whose special training and experience are best adapted to the work. Here strenuousness is expected; and an immediate commencement of investigation and prompt report are required. Sometimes the subject may be such as to call for a long line of frequent tests which necessitate patient and accurate attention to minute details. Results must be reported often--daily, or possibly with still greater frequency. Edison does not forget what is going on; but in his daily tours through the laboratory keeps in touch with all the work that is under the hands of his various a.s.sistants, showing by an instant grasp of the present conditions of any experiment that he has a full consciousness of its meaning and its reference to his original conception.

The year 1869 saw the beginning of Edison's career as an acknowledged inventor of commercial devices. From the outset, an innate recognition of system dictated the desirability and wisdom of preserving records of his experiments and inventions. The primitive records, covering the earliest years, were mainly jotted down on loose sheets of paper covered with sketches, notes, and data, pasted into large sc.r.a.p-books, or preserved in packages; but with the pa.s.sing of years and enlargement of his interests, it became the practice to make all original laboratory notes in large, uniform books. This course was pursued until the Menlo Park period, when he inst.i.tuted a new regime that has been continued down to the present day. A standard form of note-book, about eight and a half by six inches, containing about two hundred pages, was adopted.

A number of these books were (and are now) always to be found scattered around in the different sections of the laboratory, and in them have been noted by Edison all his ideas, sketches, and memoranda. Details of the various experiments concerning them have been set down by his a.s.sistants from time to time.

These later laboratory note-books, of which there are now over one thousand in the series, are eloquent in the history they reveal of the strenuous labors of Edison and his a.s.sistants and the vast fields of research he has covered during the last thirty years. They are overwhelmingly rich in biographic material, but a.n.a.lysis would be a prohibitive task for one person, and perhaps interesting only to technical readers. Their pages cover practically every department of science. The countless thousands of separate experiments recorded exhibit the operations of a master mind seeking to surprise Nature into a betrayal of her secrets by asking her the same question in a hundred different ways. For instance, when Edison was investigating a certain problem of importance many years ago, the note-books show that on this point alone about fifteen thousand experiments and tests were made by one of his a.s.sistants.

A most casual glance over these note-books will ill.u.s.trate the following remark, which was made to one of the writers not long ago by a member of the laboratory staff who has been experimenting there for twenty years: "Edison can think of more ways of doing a thing than any man I ever saw or heard of. He tries everything and never lets up, even though failure is apparently staring him in the face. He only stops when he simply can't go any further on that particular line. When he decides on any mode of procedure he gives his notes to the experimenter and lets him alone, only stepping in from time to time to look at the operations and receive reports of progress."

The history of the development of the telephone transmitter, phonograph, incandescent lamp, dynamo, electrical distributing systems from central stations, electric railway, ore-milling, cement, motion pictures, and a host of minor inventions may be found embedded in the laboratory note-books. A pa.s.sing glance at a few pages of these written records will serve to ill.u.s.trate, though only to a limited extent, the thoroughness of Edison's method. It is to be observed that these references can be but of the most meagre kind, and must be regarded as merely throwing a side-light on the subject itself. For instance, the complex problem of a practical telephone transmitter gave rise to a series of most exhaustive experiments. Combinations in almost infinite variety, including gums, chemical compounds, oils, minerals, and metals were suggested by Edison; and his a.s.sistants were given long lists of materials to try with reference to predetermined standards of articulation, degrees of loudness, and perfection of hissing sounds. The note-books contain hundreds of pages showing that a great many thousands of experiments were tried and pa.s.sed upon. Such remarks as "N. G."; "Pretty good"; "Whistling good, but no articulation"; "Rattly"; "Articulation, whispering, and whistling good"; "Best to-night so far"; and others are noted opposite the various combinations as they were tried. Thus, one may follow the investigation through a maze of experiments which led up to the successful invention of the carbon b.u.t.ton transmitter, the vital device to give the telephone its needed articulation and perfection.

The two hundred and odd note-books, covering the strenuous period during which Edison was carrying on his electric-light experiments, tell on their forty thousand pages or more a fascinating story of the evolution of a new art in its entirety. From the crude beginnings, through all the varied phases of this evolution, the operations of a master mind are apparent from the contents of these pages, in which are recorded the innumerable experiments, calculations, and tests that ultimately brought light out of darkness.

The early work on a metallic conductor for lamps gave rise to some very thorough research on melting and alloying metals, the preparation of metallic oxides, the coating of fine wires by immersing them in a great variety of chemical solutions. Following his usual custom, Edison would indicate the lines of experiment to be followed, which were carried out and recorded in the note-books. He himself, in January, 1879, made personally a most minute and searching investigation into the properties and behavior of plating-iridium, boron, rutile, zircon, chromium, molybdenum, and nickel, under varying degrees of current strength, on which there may be found in the notes about forty pages of detailed experiments and deductions in his own handwriting, concluding with the remark (about nickel): "This is a great discovery for electric light in the way of economy."

This period of research on nickel, etc., was evidently a trying one, for after nearly a month's close application he writes, on January 27, 1879: "Owing to the enormous power of the light my eyes commenced to pain after seven hours' work, and I had to quit." On the next day appears the following entry: "Suffered the pains of h.e.l.l with my eyes last night from 10 P.M. till 4 A.M., when got to sleep with a big dose of morphine.

Eyes getting better, and do not pain much at 4 P.M.; but I lose to-day."

The "try everything" spirit of Edison's method is well ill.u.s.trated in this early period by a series of about sixteen hundred resistance tests of various ores, minerals, earths, etc., occupying over fifty pages of one of the note-books relating to the metallic filament for his lamps.

But, as the reader has already learned, the metallic filament was soon laid aside in favor of carbon, and we find in the laboratory notes an amazing record of research and experiment conducted in the minute and searching manner peculiar to Edison's method. His inquiries were directed along all the various roads leading to the desired goal, for long before he had completed the invention of a practical lamp he realized broadly the fundamental requirements of a successful system of electrical distribution, and had given instructions for the making of a great variety of calculations which, although far in advance of the time, were clearly foreseen by him to be vitally important in the ultimate solution of the complicated problem. Thus we find many hundreds of pages of the note-books covered with computations and calculations by Mr. Upton, not only on the numerous ramifications of the projected system and comparisons with gas, but also on proposed forms of dynamos and the proposed station in New York. A mere recital by t.i.tles of the vast number of experiments and tests on carbons, lamps, dynamos, armatures, commutators, windings, systems, regulators, sockets, vacuum-pumps, and the thousand and one details relating to the subject in general, originated by Edison, and methodically and systematically carried on under his general direction, would fill a great many pages here, and even then would serve only to convey a confused impression of ceaseless probing.

It is possible only to a broad, comprehensive mind well stored with knowledge, and backed with resistless, boundless energy, that such a diversified series of experiments and investigations could be carried on simultaneously and a.s.similated, even though they should relate to a cla.s.s of phenomena already understood and well defined. But if we pause to consider that the commercial subdivision of the electric current (which was virtually an invention made to order) involved the solution of problems so unprecedented that even they themselves had to be created, we cannot but conclude that the afflatus of innate genius played an important part in the unique methods of investigation inst.i.tuted by Edison at that and other times.

The idea of attributing great successes to "genius" has always been repudiated by Edison, as evidenced by his historic remark that "Genius is 1 per cent. inspiration and 99 per cent. perspiration." Again, in a conversation many years ago at the laboratory between Edison, Batchelor, and E. H. Johnson, the latter made allusion to Edison's genius as evidenced by some of his achievements, when Edison replied:

"Stuff! I tell you genius is hard work, stick-to-it-iveness, and common sense."

"Yes," said Johnson, "I admit there is all that to it, but there's still more. Batch and I have those qualifications, but although we knew quite a lot about telephones, and worked hard, we couldn't invent a brand-new non-infringing telephone receiver as you did when Gouraud cabled for one. Then, how about the subdivision of the electric light?"

"Electric current," corrected Edison.

"True," continued Johnson; "you were the one to make that very distinction. The scientific world had been working hard on subdivision for years, using what appeared to be common sense. Results worse than nil. Then you come along, and about the first thing you do, after looking the ground over, is to start off in the opposite direction, which subsequently proves to be the only possible way to reach the goal.

It seems to me that this is pretty close to the dictionary definition of genius."

It is said that Edison replied rather incoherently and changed the topic of conversation.

This innate modesty, however, does not prevent Edison from recognizing and cla.s.sifying his own methods of investigation. In a conversation with two old a.s.sociates recently (April, 1909), he remarked: "It has been said of me that my methods are empirical. That is true only so far as chemistry is concerned. Did you ever realize that practically all industrial chemistry is colloidal in its nature? Hard rubber, celluloid, gla.s.s, soap, paper, and lots of others, all have to deal with amorphous substances, as to which comparatively little has been really settled.

My methods are similar to those followed by Luther Burbank. He plants an acre, and when this is in bloom he inspects it. He has a sharp eye, and can pick out of thousands a single plant that has promise of what he wants. From this he gets the seed, and uses his skill and knowledge in producing from it a number of new plants which, on development, furnish the means of propagating an improved variety in large quant.i.ty. So, when I am after a chemical result that I have in mind, I may make hundreds or thousands of experiments out of which there may be one that promises results in the right direction. This I follow up to its legitimate conclusion, discarding the others, and usually get what I am after.

There is no doubt about this being empirical; but when it comes to problems of a mechanical nature, I want to tell you that all I've ever tackled and solved have been done by hard, logical thinking." The intense earnestness and emphasis with which this was said were very impressive to the auditors. This empirical method may perhaps be better ill.u.s.trated by a specific example. During the latter part of the storage battery investigations, after the form of positive element had been determined upon, it became necessary to ascertain what definite proportions and what quality of nickel hydrate and nickel flake would give the best results. A series of positive tubes were filled with the two materials in different proportions--say, nine parts hydrate to one of flake; eight parts hydrate to two of flake; seven parts hydrate to three of flake, and so on through varying proportions. Three sets of each of these positives were made, and all put into separate test tubes with a uniform type of negative element. These were carried through a long series of charges and discharges under strict test conditions. From the tabulated results of hundreds of tests there were selected three that showed the best results. These, however, showed only the superiority of certain PROPORTIONS of the materials. The next step would be to find out the best QUALITY. Now, as there are several hundred variations in the quality of nickel flake, and perhaps a thousand ways to make the hydrate, it will be realized that Edison's methods led to stupendous detail, for these tests embraced a trial of all the qualities of both materials in the three proportions found to be most suitable.

Among these many thousands of experiments any that showed extraordinary results were again elaborated by still further series of tests, until Edison was satisfied that he had obtained the best result in that particular line.

The laboratory note-books do not always tell the whole story or meaning of an experiment that may be briefly outlined on one of their pages. For example, the early filament made of a mixture of lampblack and tar is merely a suggestion in the notes, but its making afforded an example of Edison's pertinacity. These materials, when mixed, became a friable ma.s.s, which he had found could be brought into such a cohesive, putty-like state by manipulation, as to be capable of being rolled out into filaments as fine as seven-thousandths of an inch in cross-section.

One of the laboratory a.s.sistants was told to make some of this mixture, knead it, and roll some filaments. After a time he brought the ma.s.s to Edison, and said:

"There's something wrong about this, for it crumbles even after manipulating it with my fingers."