Edison: His Life and Inventions

by Frank Lewis Dyer; Thomas Commerford Martin

An interesting story of meter experience in the first few months of operation of the Pearl Street station is told by one of the "boys" who was then in position to know the facts; "Mr. J. P. Morgan, whose firm was one of the first customers, expressed to Mr. Edison some doubt as to the accuracy of the meter. The latter, firmly convinced of its correctness, suggested a strict test by having some cards printed and hung on each fixture at Mr. Morgan's place. On these cards was to be noted the number of lamps in the fixture, and the time they were turned on and off each day for a month. At the end of that time the lamp-hours were to be added together by one of the clerks and figured on a basis of a definite amount per lamp-hour, and compared with the bill that would be rendered by the station for the corresponding period. The results of the first month's test showed an apparent overcharge by the Edison company. Mr. Morgan was exultant, while Mr. Edison was still confident and suggested a continuation of the test. Another month's trial showed somewhat similar results. Mr. Edison was a little disturbed, but insisted that there was a mistake somewhere. He went down to Drexel, Morgan & Company's office to investigate, and, after looking around, asked when the office was cleaned out. He was told it was done at night by the janitor, who was sent for, and upon being interrogated as to what light he used, said that he turned on a central fixture containing about ten lights. It came out that he had made no record of the time these lights were in use. He was told to do so in future, and another month's test was made. On comparison with the company's bill, rendered on the meter-reading, the meter came within a few cents of the amount computed from the card records, and Mr. Morgan was completely satisfied of the accuracy of the meter."

It is a strange but not extraordinary commentary on the perversity of human nature and the lack of correct observation, to note that even after the Pearl Street station had been in actual operation twenty-four hours a day for nearly three months, there should still remain an attitude of "can't be done." That such a scepticism still obtained is evidenced by the public prints of the period. Edison's electric-light system and his broad claims were freely discussed and animadverted upon at the very time he was demonstrating their successful application. To show some of the feeling at the time, we reproduce the following letter, which appeared November 29, 1882:

"To the Editor of the Sun:

"SIR,—In reading the discussions relative to the Pearl Street station of the Edison light, I have noted that while it is claimed that there is scarcely any loss from leakage of current, nothing is said about the loss due to the resistance of the long circuits. I am informed that this is the secret of the failure to produce with the power in position a sufficient amount of current to run all the lamps that have been put up, and that while six, and even seven, lights to the horse-power may be produced from an isolated plant, the resistance of the long underground wires reduces this result in the above case to less than three lights to the horse-power, thus making the cost of production greatly in excess of gas. Can the Edison company explain this? 'INVESTIGATOR'."

This was one of the many anonymous letters that had been written to the newspapers on the subject, and the following reply by the Edison company was printed December 3, 1882:

"To the Editor of the Sun:

"SIR,—'Investigator' in Wednesday's Sun, says that the Edison company is troubled at its Pearl Street station with a 'loss of current, due to the resistance of the long circuits'; also that, whereas Edison gets 'six or even seven lights to the horse-power in isolated plants, the resistance of the long underground wires reduces that result in the Pearl Street station to less than three lights to the horse-power.' Both of these statements are false. As regards loss due to resistance, there is a well-known law for determining it, based on Ohm's law. By use of that law we knew in advance, that is to say, when the original plans for the station were drawn, just what this loss would be, precisely the same as a mechanical engineer when constructing a mill with long lines of shafting can forecast the loss of power due to friction. The practical result in the Pearl Street station has fully demonstrated the correctness of our estimate thus made in advance. As regards our getting only three lights per horse-power, our station has now been running three months, without stopping a moment, day or night, and we invariably get over six lamps per horse-power, or substantially the same as we do in our isolated plants. We are now lighting one hundred and ninety-three buildings, wired for forty-four hundred lamps, of which about two-thirds are in constant use, and we are adding additional houses and lamps daily. These figures can be verified at the office of the Board of Underwriters, where certificates with full details permitting the use of our light are filed by their own inspector. To light these lamps we run from one to three dynamos, according to the lamps in use at any given time, and we shall start additional dynamos as fast as we can connect more buildings. Neither as regards the loss due to resistance, nor as regards the number of lamps per horse-power, is there the slightest trouble or disappointment on the part of our company, and your correspondent is entirely in error is assuming that there is. Let me suggest that if 'Investigator' really wishes to investigate, and is competent and willing to learn the exact facts, he can do so at this office, where there is no mystery of concealment, but, on the contrary, a strong desire to communicate facts to intelligent inquirers. Such a method of investigating must certainly be more satisfactory to one honestly seeking knowledge than that of first assuming an error as the basis of a question, and then demanding an explanation.

"Yours very truly,

"S. B. EATON, President."

Viewed from the standpoint of over twenty-seven years later, the wisdom and necessity of answering anonymous newspaper letters of this kind might be deemed questionable, but it must be remembered that, although the Pearl Street station was working successfully, and Edison's comprehensive plans were abundantly vindicated, the enterprise was absolutely new and only just stepping on the very threshold of commercial exploitation. To enter in and possess the land required the confidence of capital and the general public. Hence it was necessary to maintain a constant vigilance to defeat the insidious attacks of carping critics and others who would attempt to injure the Edison system by misleading statements.