On the outskirts of the property was a small building in which lampblack was crudely but carefully manufactured and pressed into very small cakes, for use in the Edison carbon transmitters of that time. The night-watchman, Alfred Swanson, took care of this curious plant, which consisted of a battery of petroleum lamps that were forced to burn to the sooting point. During his rounds in the night Swanson would find time to collect from the chimneys the soot that the lamps gave. It was then weighed out into very small portions, which were pressed into cakes or buttons by means of a hand-press. These little cakes were delicately packed away between layers of cotton in small, light boxes and shipped to Bergmann in New York, by whom the telephone transmitters were being made. A little later the Edison electric railway was built on the confines of the property out through the woods, at first only a third of a mile in length, but reaching ultimately to Pumptown, almost three miles away.
Mr. Edison's own words may be quoted as to the men with whom he surrounded himself here and upon whose services he depended principally for help in the accomplishment of his aims. In an autobiographical article in the Electrical World of March 5, 1904, he says: "It is interesting to note that in addition to those mentioned above (Charles Batchelor and Frank Upton), I had around me other men who ever since have remained active in the field, such as Messrs. Francis Jehl, William J. Hammer, Martin Force, Ludwig K. Boehm, not forgetting that good friend and co-worker, the late John Kruesi. They found plenty to do in the various developments of the art, and as I now look back I sometimes wonder how we did so much in so short a time." Mr. Jehl in his reminiscences adds another name to the above—namely, that of John W. Lawson, and then goes on to say: "These are the names of the pioneers of incandescent lighting, who were continuously at the side of Edison day and night for some years, and who, under his guidance, worked upon the carbon-filament lamp from its birth to ripe maturity. These men all had complete faith in his ability and stood by him as on a rock, guarding their work with the secretiveness of a burglar-proof safe. Whenever it leaked out in the world that Edison was succeeding in his work on the electric light, spies and others came to the Park; so it was of the utmost importance that the experiments and their results should be kept a secret until Edison had secured the protection of the Patent Office." With this staff was associated from the first Mr. E. H. Johnson, whose work with Mr. Edison lay chiefly, however, outside the laboratory, taking him to all parts of the country and to Europe. There were also to be regarded as detached members of it the Bergmann brothers, manufacturing for Mr. Edison in New York, and incessantly experimenting for him. In addition there must be included Mr. Samuel Insull, whose activities for many years as private secretary and financial manager were devoted solely to Mr. Edison's interests, with Menlo Park as a centre and main source of anxiety as to pay-rolls and other constantly recurring obligations. The names of yet other associates occur from time to time in this narrative—"Edison men" who have been very proud of their close relationship to the inventor and his work at old Menlo. "There was also Mr. Charles L. Clarke, who devoted himself mainly to engineering matters, and later on acted as chief engineer of the Edison Electric Light Company for some years. Then there were William Holzer and James Hipple, both of whom took an active part in the practical development of the glass-blowing department of the laboratory, and, subsequently, at the first Edison lamp factory at Menlo Park. Later on Messrs. Jehl, Hipple, and Force assisted Mr. Batchelor to install the lamp-works of the French Edison Company at Ivry-sur-Seine. Then there were Messrs. Charles T. Hughes, Samuel D. Mott, and Charles T. Mott, who devoted their time chiefly to commercial affairs. Mr. Hughes conducted most of this work, and later on took a prominent part in Edison's electric-railway experiments. His business ability was on a high level, while his personal character endeared him to us all."
Among other now well-known men who came to us and assisted in various kinds of work were Messrs. Acheson, Worth, Crosby, Herrick, and Hill, while Doctor Haid was placed by Mr. Edison in charge of a special chemical laboratory. Dr. E. L. Nichols was also with us for a short time conducting a special series of experiments. There was also Mr. Isaacs, who did a great deal of photographic work, and to whom we must be thankful for the pictures of Menlo Park in connection with Edison's work.
"Among others who were added to Mr. Kruesi's staff in the machine-shop were Messrs. J. H. Vail and W. S. Andrews. Mr. Vail had charge of the dynamo-room. He had a good general knowledge of machinery, and very soon acquired such familiarity with the dynamos that he could skip about among them with astonishing agility to regulate their brushes or to throw rosin on the belts when they began to squeal. Later on he took an active part in the affairs and installations of the Edison Light Company. Mr. Andrews stayed on Mr. Kruesi's staff as long as the laboratory machine-shop was kept open, after which he went into the employ of the Edison Electric Light Company and became actively engaged in the commercial and technical exploitation of the system. Another man who was with us at Menlo Park was Mr. Herman Claudius, an Austrian, who at one time was employed in connection with the State Telegraphs of his country. To him Mr. Edison assigned the task of making a complete model of the network of conductors for the contemplated first station in New York."
Mr. Francis R. Upton, who was early employed by Mr. Edison as his mathematician, furnishes a pleasant, vivid picture of his chief associates engaged on the memorable work at Menlo Park. He says: "Mr. Charles Batchelor was Mr. Edison's principal assistant at that time. He was an Englishman, and came to this country to set up the thread-weaving machinery for the Clark thread-works. He was a most intelligent, patient, competent, and loyal assistant to Mr. Edison. I remember distinctly seeing him work many hours to mount a small filament; and his hand would be as steady and his patience as unyielding at the end of those many hours as it was at the beginning, in spite of repeated failures. He was a wonderful mechanic; the control that he had of his fingers was marvellous, and his eyesight was sharp. Mr. Batchelor's judgment and good sense were always in evidence.
"Mr. Kruesi was the superintendent, a Swiss trained in the best Swiss ideas of accuracy. He was a splendid mechanic with a vigorous temper, and wonderful ability to work continuously and to get work out of men. It was an ideal combination, that of Edison, Batchelor, and Kruesi. Mr. Edison with his wonderful flow of ideas which were sharply defined in his mind, as can be seen by any of the sketches that he made, as he evidently always thinks in three dimensions; Mr. Kruesi, willing to take the ideas, and capable of comprehending them, would distribute the work so as to get it done with marvellous quickness and great accuracy. Mr. Batchelor was always ready for any special fine experimenting or observation, and could hold to whatever he was at as long as Mr. Edison wished; and always brought to bear on what he was at the greatest skill."
While Edison depended upon Upton for his mathematical work, he was wont to check it up in a very practical manner, as evidenced by the following incident described by Mr. Jehl: "I was once with Mr. Upton calculating some tables which he had put me on, when Mr. Edison appeared with a glass bulb having a pear-shaped appearance in his hand. It was the kind that we were going to use for our lamp experiments; and Mr. Edison asked Mr. Upton to please calculate for him its cubic contents in centimetres. Now Mr. Upton was a very able mathematician, who, after he finished his studies at Princeton, went to Germany and got his final gloss under that great master, Helmholtz. Whatever he did and worked on was executed in a pure mathematical manner, and any wrangler at Oxford would have been delighted to see him juggle with integral and differential equations, with a dexterity that was surprising. He drew the shape of the bulb exactly on paper, and got the equation of its lines with which he was going to calculate its contents, when Mr. Edison again appeared and asked him what it was. He showed Edison the work he had already done on the subject, and told him that he would very soon finish calculating it. 'Why,' said Edison, 'I would simply take that bulb and fill it with mercury and weigh it; and from the weight of the mercury and its specific gravity I'll get it in five minutes, and use less mental energy than is necessary in such a fatiguing operation.'"
Menlo Park became ultimately the centre of Edison's business life as it was of his inventing. After the short distasteful period during the introduction of his lighting system, when he spent a large part of his time at the offices at 65 Fifth Avenue, New York, or on the actual work connected with the New York Edison installation, he settled back again in Menlo Park altogether. Mr. Samuel Insull describes the business methods which prevailed throughout the earlier Menlo Park days of "storm and stress," and the curious conditions with which he had to deal as private secretary: "I never attempted to systematize Edison's business life. Edison's whole method of work would upset the system of any office. He was just as likely to be at work in his laboratory at midnight as midday. He cared not for the hours of the day or the days of the week. If he was exhausted he might more likely be asleep in the middle of the day than in the middle of the night, as most of his work in the way of inventions was done at night. I used to run his office on as close business methods as my experience admitted; and I would get at him whenever it suited his convenience. Sometimes he would not go over his mail for days at a time; but other times he would go regularly to his office in the morning. At other times my engagements used to be with him to go over his business affairs at Menlo Park at night, if I was occupied in New York during the day. In fact, as a matter of convenience I used more often to get at him at night, as it left my days free to transact his affairs, and enabled me, probably at a midnight luncheon, to get a few minutes of his time to look over his correspondence and get his directions as to what I should do in some particular negotiation or matter of finance. While it was a matter of suiting Edison's convenience as to when I should transact business with him, it also suited my own ideas, as it enabled me after getting through my business with him to enjoy the privilege of watching him at his work, and to learn something about the technical side of matters. Whatever knowledge I may have of the electric light and power industry I feel I owe it to the tuition of Edison. He was about the most willing tutor, and I must confess that he had to be a patient one."
Here again occurs the reference to the incessant night-work at Menlo Park, a note that is struck in every reminiscence and in every record of the time. But it is not to be inferred that the atmosphere of grim determination and persistent pursuit of the new invention characteristic of this period made life a burden to the small family of laborers associated with Edison. Many a time during the long, weary nights of experimenting Edison would call a halt for refreshments, which he had ordered always to be sent in when night-work was in progress. Everything would be dropped, all present would join in the meal, and the last good story or joke would pass around. In his notes Mr. Jehl says: "Our lunch always ended with a cigar, and I may mention here that although Edison was never fastidious in eating, he always relished a good cigar, and seemed to find in it consolation and solace.... It often happened that while we were enjoying the cigars after our midnight repast, one of the boys would start up a tune on the organ and we would all sing together, or one of the others would give a solo. Another of the boys had a voice that sounded like something between the ring of an old tomato can and a pewter jug. He had one song that he would sing while we roared with laughter. He was also great in imitating the tin-foil phonograph.... When Boehm was in good-humor he would play his zither now and then, and amuse us by singing pretty German songs. On many of these occasions the laboratory was the rendezvous of jolly and convivial visitors, mostly old friends and acquaintances of Mr. Edison. Some of the office employees would also drop in once in a while, and as everybody present was always welcome to partake of the midnight meal, we all enjoyed these gatherings. After a while, when we were ready to resume work, our visitors would intimate that they were going home to bed, but we fellows could stay up and work, and they would depart, generally singing some song like Good-night, ladies! . . . It often happened that when Edison had been working up to three or four o'clock in the morning, he would lie down on one of the laboratory tables, and with nothing but a couple of books for a pillow, would fall into a sound sleep. He said it did him more good than being in a soft bed, which spoils a man. Some of the laboratory assistants could be seen now and then sleeping on a table in the early morning hours. If their snoring became objectionable to those still at work, the 'calmer' was applied. This machine consisted of a Babbitt's soap box without a cover. Upon it was mounted a broad ratchet-wheel with a crank, while into the teeth of the wheel there played a stout, elastic slab of wood. The box would be placed on the table where the snorer was sleeping and the crank turned rapidly. The racket thus produced was something terrible, and the sleeper would jump up as though a typhoon had struck the laboratory. The irrepressible spirit of humor in the old days, although somewhat strenuous at times, caused many a moment of hilarity which seemed to refresh the boys, and enabled them to work with renewed vigor after its manifestation." Mr. Upton remarks that often during the period of the invention of the incandescent lamp, when under great strain and fatigue, Edison would go to the organ and play tunes in a primitive way, and come back to crack jokes with the staff. "But I have often felt that Mr. Edison never could comprehend the limitations of the strength of other men, as his own physical and mental strength have always seemed to be without limit. He could work continuously as long as he wished, and had sleep at his command. His sleep was always instant, profound, and restful. He has told me that he never dreamed. I have known Mr. Edison now for thirty-one years, and feel that he has always kept his mind direct and simple, going straight to the root of troubles. One of the peculiarities I have noticed is that I have never known him to break into a conversation going on around him, and ask what people were talking about. The nearest he would ever come to it was when there had evidently been some story told, and his face would express a desire to join in the laugh, which would immediately invite telling the story to him."
Next to those who worked with Edison at the laboratory and were with him constantly at Menlo Park were the visitors, some of whom were his business associates, some of them scientific men, and some of them hero-worshippers and curiosity-hunters. Foremost in the first category was Mr. E. H. Johnson, who was in reality Edison's most intimate friend, and was required for constant consultation; but whose intense activity, remarkable grasp of electrical principles, and unusual powers of exposition, led to his frequent detachment for long trips, including those which resulted in the introduction of the telephone, phonograph, and electric light in England and on the Continent. A less frequent visitor was Mr. S. Bergmann, who had all he needed to occupy his time in experimenting and manufacturing, and whose contemporaneous Wooster Street letter-heads advertised Edison's inventions as being made there, Among the scientists were Prof. George F. Barker, of Philadelphia, a big, good-natured philosopher, whose valuable advice Edison esteemed highly. In sharp contrast to him was the earnest, serious Rowland, of Johns Hopkins University, afterward the leading American physicist of his day. Profs. C. F. Brackett and C. F. Young, of Princeton University, were often received, always interested in what Edison was doing, and proud that one of their own students, Mr. Upton, was taking such a prominent part in the development of the work.