|Back||1 2 3 4 5||Next|
Mr. Edison was consulting electrician for the Electric Railway Company, but neither a director nor an executive officer. Just what the trouble was as to the internal management of the corporation it is hard to determine a quarter of a century later; but it was equipped with all essential elements to dominate an art in which after its first efforts it remained practically supine and useless, while other interests forged ahead and reaped both the profit and the glory. Dissensions arose between the representatives of the Field and Edison interests, and in April, 1890, the Railway Company assigned its rights to the Edison patents to the Edison General Electric Company, recently formed by the consolidation of all the branches of the Edison light, power, and manufacturing industry under one management. The only patent rights remaining to the Railway Company were those under three Field patents, one of which, with controlling claims, was put in suit June, 1890, against the Jamaica & Brooklyn Road Company, a customer of the Edison General Electric Company. This was, to say the least, a curious and anomalous situation. Voluminous records were made by both parties to the suit, and in the spring of 1894 the case was argued before the late Judge Townsend, who wrote a long opinion dismissing the bill of complaint. The student will find therein a very complete and careful study of the early electric-railway art. After this decision was rendered, the Electric Railway Company remained for several years in a moribund condition, and on the last day of 1896 its property was placed in the hands of a receiver. In February of 1897 the receiver sold the three Field patents to their original owner, and he in turn sold them to the Westinghouse Electric and Manufacturing Company. The Railway Company then went into voluntary dissolution, a sad example of failure to seize the opportunity at the psychological moment, and on the part of the inventor to secure any adequate return for years of effort and struggle in founding one of the great arts. Neither of these men was squelched by such a calamitous result, but if there were not something of bitterness in their feelings as they survey what has come of their work, they would not be human.
As a matter of fact, Edison retained a very lively interest in electric-railway progress long after the pregnant days at Menlo Park, one of the best evidences of which is an article in the New York Electrical Engineer of November 18, 1891, which describes some important and original experiments in the direction of adapting electrical conditions to the larger cities. The overhead trolley had by that time begun its victorious career, but there was intense hostility displayed toward it in many places because of the inevitable increase in the number of overhead wires, which, carrying, as they did, a current of high voltage and large quantity, were regarded as a menace to life and property. Edison has always manifested a strong objection to overhead wires in cities, and urged placing them underground; and the outcry against the overhead "deadly" trolley met with his instant sympathy. His study of the problem brought him to the development of the modern "substation," although the twists that later evolutions have given the idea have left it scarcely recognizable.
 See 61 Fed. Rep. 655.
Mr. Villard, as President of the Edison General Electric Company, requested Mr. Edison, as electrician of the company, to devise a street-railway system which should be applicable to the largest cities where the use of the trolley would not be permitted, where the slot conduit system would not be used, and where, in general, the details of construction should be reduced to the simplest form. The limits imposed practically were such as to require that the system should not cost more than a cable road to install. Edison reverted to his ingenious lighting plan of years earlier, and thus settled on a method by which current should be conveyed from the power plant at high potential to motor-generators placed below the ground in close proximity to the rails. These substations would convert the current received at a pressure of, say, one thousand volts to one of twenty volts available between rail and rail, with a corresponding increase in the volume of the current. With the utilization of heavy currents at low voltage it became necessary, of course, to devise apparatus which should be able to pick up with absolute certainty one thousand amperes of current at this press- ure through two inches of mud, if necessary. With his wonted activity and fertility Edison set about devising such a contact, and experimented with metal wheels under all conditions of speed and track conditions. It was several months before he could convey one hundred amperes by means of such contacts, but he worked out at last a satisfactory device which was equal to the task. The next point was to secure a joint between contiguous rails such as would permit of the passage of several thousand amperes without introducing undue resistance. This was also accomplished.
Objections were naturally made to rails out in the open on the street surface carrying large currents at a potential of twenty volts. It was said that vehicles with iron wheels passing over the tracks and spanning the two rails would short-circuit the current, "chew" themselves up, and destroy the dynamos generating the current by choking all that tremendous amount of energy back into them. Edison tackled the objection squarely and short-circuited his track with such a vehicle, but succeeded in getting only about two hundred amperes through the wheels, the low voltage and the insulating properties of the axle- grease being sufficient to account for such a result. An iron bar was also used, polished, and with a man standing on it to insure solid contact; but only one thousand amperes passed through it--i.e., the amount required by a single car, and, of course, much less than the capacity of the generators able to operate a system of several hundred cars.
Further interesting experiments showed that the expected large leakage of current from the rails in wet weather did not materialize. Edison found that under the worst conditions with a wet and salted track, at a potential difference of twenty volts between the two rails, the extreme loss was only two and one-half horse-power. In this respect the phenomenon followed the same rule as that to which telegraph wires are subject--namely, that the loss of insulation is greater in damp, murky weather when the insulators are covered with wet dust than during heavy rains when the insulators are thoroughly washed by the action of the water. In like manner a heavy rain-storm cleaned the tracks from the accumulations due chiefly to the droppings of the horses, which otherwise served largely to increase the conductivity. Of course, in dry weather the loss of current was practically nothing, and, under ordinary conditions, Edison held, his system was in respect to leakage and the problems of electrolytic attack of the current on adjacent pipes, etc., as fully insulated as the standard trolley network of the day. The cost of his system Mr. Edison placed at from $30,000 to $100,000 per mile of double track, in accordance with local conditions, and in this respect comparing very favorably with the cable systems then so much in favor for heavy traffic. All the arguments that could be urged in support of this ingenious system are tenable and logical at the present moment; but the trolley had its way except on a few lines where the conduit-and-shoe method was adopted; and in the intervening years the volume of traffic created and handled by electricity in centres of dense population has brought into existence the modern subway.
But down to the moment of the preparation of this biography, Edison has retained an active interest in transportation problems, and his latest work has been that of reviving the use of the storage battery for street-car purposes. At one time there were a number of storage-battery lines and cars in operation in such cities as Washington, New York, Chicago, and Boston; but the costs of operation and maintenance were found to be inordinately high as compared with those of the direct-supply methods, and the battery cars all disappeared. The need for them under many conditions remained, as, for example, in places in Greater New York where the overhead trolley wires are forbidden as objectionable, and where the ground is too wet or too often submerged to permit of the conduit with the slot. Some of the roads in Greater New York have been anxious to secure such cars, and, as usual, the most resourceful electrical engineer and inventor of his times has made the effort. A special experimental track has been laid at the Orange laboratory, and a car equipped with the Edison storage battery and other devices has been put under severe and extended trial there and in New York.
Menlo Park, in ruin and decay, affords no traces of the early Edison electric-railway work, but the crude little locomotive built by Charles T. Hughes was rescued from destruction, and has become the property of the Pratt Institute, of Brooklyn, towhose thousands of technical students it is a constant example and incentive. It was loaned in 1904 to the Association of Edison Illuminating Companies, and by it exhibited as part of the historical Edison collection at the St. Louis Exposition.
|Back||1 2 3 4 5||Next|
Edison, His Life and Inventions -by- F. L. Dyer and T. C. MartinBottom Content goes here. Wikipedia content requires these links..... Wikipedia content is licensed under the GNU Free Documentation License.