Edison: His Life and Inventions

by Frank Lewis Dyer; Thomas Commerford Martin

Supplementing the story of Mr. Andrews is that of Lieut. F. J. Sprague, who also gives a curious glimpse of the glorious uncertainties and vicissitudes of that formative period. Mr. Sprague served on the jury at the Crystal Palace Exhibition with Darwin's son—the present Sir Horace—and after the tests were ended left the Navy and entered Edison's service at the suggestion of Mr. E. H. Johnson, who was Edison's shrewd recruiting sergeant in those days: "I resigned sooner than Johnson expected, and he had me on his hands. Meanwhile he had called upon me to make a report of the three-wire system, known in England as the Hopkinson, both Dr. John Hopkinson and Mr. Edison being independent inventors at practically the same time. I reported on that, left London, and landed in New York on the day of the opening of the Brooklyn Bridge in 1883—May 24—with a year's leave of absence.

"I reported at the office of Mr. Edison on Fifth Avenue and told him I had seen Johnson. He looked me over and said: 'What did he promise you?' I replied: 'Twenty-five hundred dollars a year.' He did not say much, but looked it. About that time Mr. Andrews and I came together. On July 2d of that year we were ordered to Sunbury, and to be ready to start the station on the fourth. The electrical work had to be done in forty-eight hours! Having travelled around the world, I had cultivated an indifference to any special difficulties of that kind. Mr. Andrews and I worked in collaboration until the night of the third. I think he was perhaps more appreciative than I was of the discipline of the Edison Construction Department, and thought it would be well for us to wait until the morning of the fourth before we started up. I said we were sent over to get going, and insisted on starting up on the night of the third. We had an Armington & Sims engine with sight-feed oiler. I had never seen one, and did not know how it worked, with the result that we soon burned up the babbitt metal in the bearings and spent a good part of the night getting them in order. The next day Mr. Edison, Mr. Insull, and the chief engineer of the construction department appeared on the scene and wanted to know what had happened. They found an engine somewhat loose in the bearings, and there followed remarks which would not look well in print. Andrews skipped from under; he obeyed orders; I did not. But the plant ran, and it was the first three-wire station in this country."

Seen from yet another angle, the worries of this early work were not merely those of the men on the "firing line." Mr. Insull, in speaking of this period, says: "When it was found difficult to push the central-station business owing to the lack of confidence in its financial success, Edison decided to go into the business of promoting and constructing central-station plants, and he formed what was known as the Thomas A. Edison Construction Department, which he put me in charge of. The organization was crude, the steam-engineering talent poor, and owing to the impossibility of getting any considerable capital subscribed, the plants were put in as cheaply as possible. I believe that this construction department was unkindly named the 'Destruction Department.' It served its purpose; never made any money; and I had the unpleasant task of presiding at its obsequies."

On July 4th the Sunbury plant was put into commercial operation by Edison, and he remained a week studying its conditions and watching for any unforeseen difficulty that might arise. Nothing happened, however, to interfere with the successful running of the station, and for twenty years thereafter the same two dynamos continued to furnish light in Sunbury. They were later used as reserve machines, and finally, with the engine, retired from service as part of the "Collection of Edisonia"; but they remain in practically as good condition as when installed in 1883.

Sunbury was also provided with the first electro-chemical meters used in the United States outside New York City, so that it served also to accentuate electrical practice in a most vital respect—namely, the measurement of the electrical energy supplied to customers. At this time and long after, all arc lighting was done on a "flat rate" basis. The arc lamp installed outside a customer's premises, or in a circuit for public street lighting, burned so many hours nightly, so many nights in the month; and was paid for at that rate, subject to rebate for hours when the lamp might be out through accident. The early arc lamps were rated to require 9 to 10 amperes of current, at 45 volts pressure each, receiving which they were estimated to give 2000 c.p., which was arrived at by adding together the light found at four different positions, so that in reality the actual light was about 500 c.p. Few of these data were ever actually used, however; and it was all more or less a matter of guesswork, although the central-station manager, aiming to give good service, would naturally see that the dynamos were so operated as to maintain as steadily as possible the normal potential and current. The same loose methods applied to the early attempts to use electric motors on arc-lighting circuits, and contracts were made based on the size of the motor, the width of the connecting belt, or the amount of power the customer thought he used—never on the measurement of the electrical energy furnished him.

Here again Edison laid the foundation of standard practice. It is true that even down to the present time the flat rate is applied to a great deal of incandescent lighting, each lamp being charged for individually according to its probable consumption during each month. This may answer, perhaps, in a small place where the manager can gauge pretty closely from actual observation what each customer does; but even then there are elements of risk and waste; and obviously in a large city such a method would soon be likely to result in financial disaster to the plant. Edison held that the electricity sold must be measured just like gas or water, and he proceeded to develop a meter. There was infinite scepticism around him on the subject, and while other inventors were also giving the subject their thought, the public took it for granted that anything so utterly intangible as electricity, that could not be seen or weighed, and only gave secondary evidence of itself at the exact point of use, could not be brought to accurate registration. The general attitude of doubt was exemplified by the incident in Mr. J. P. Morgan's office, noted in the last chapter. Edison, however, had satisfied himself that there were various ways of accomplishing the task, and had determined that the current should be measured on the premises of every consumer. His electrolytic meter was very successful, and was of widespread use in America and in Europe until the perfection of mechanical meters by Elihu Thomson and others brought that type into general acceptance. Hence the Edison electrolytic meter is no longer used, despite its excellent qualities. Houston & Kennelly in their Electricity in Everyday Life sum the matter up as follows: "The Edison chemical meter is capable of giving fair measurements of the amount of current passing. By reason, however, of dissatisfaction caused from the inability of customers to read the indications of the meter, it has in later years, to a great extent, been replaced by registering meters that can be read by the customer."

The principle employed in the Edison electrolytic meter is that which exemplifies the power of electricity to decompose a chemical substance. In other words it is a deposition bath, consisting of a glass cell in which two plates of chemically pure zinc are dipped in a solution of zinc sulphate. When the lights or motors in the circuit are turned on, and a certain definite small portion of the current is diverted to flow through the meter, from the positive plate to the negative plate, the latter increases in weight by receiving a deposit of metallic zinc; the positive plate meantime losing in weight by the metal thus carried away from it. This difference in weight is a very exact measure of the quantity of electricity, or number of ampere-hours, that have, so to speak, passed through the cell, and hence of the whole consumption in the circuit. The amount thus due from the customer is ascertained by removing the cell, washing and drying the plates, and weighing them in a chemical balance. Associated with this simple form of apparatus were various ingenious details and refinements to secure regularity of operation, freedom from inaccuracy, and immunity from such tampering as would permit theft of current or damage. As the freezing of the zinc sulphate solution in cold weather would check its operation, Edison introduced, for example, into the meter an incandescent lamp and a thermostat so arranged that when the temperature fell to a certain point, or rose above another point, it was cut in or out; and in this manner the meter could be kept from freezing. The standard Edison meter practice was to remove the cells once a month to the meter-room of the central-station company for examination, another set being substituted. The meter was cheap to manufacture and install, and not at all liable to get out of order.

In December, 1888, Mr. W. J. Jenks read an interesting paper before the American Institute of Electrical Engineers on the six years of practical experience had up to that time with the meter, then more generally in use than any other. It appears from the paper that twenty-three Edison stations were then equipped with 5187 meters, which were relied upon for billing the monthly current consumption of 87,856 lamps and 350 motors of 1000 horse-power total. This represented about 75 per cent. of the entire lamp capacity of the stations. There was an average cost per lamp for meter operation of twenty-two cents a year, and each meter took care of an average of seventeen lamps. It is worthy of note, as to the promptness with which the Edison stations became paying properties, that four of the metered stations were earning upward of 15 per cent. on their capital stock; three others between 8 and 10 per cent.; eight between 5 and 8 per cent.; the others having been in operation too short a time to show definite results, although they also went quickly to a dividend basis. Reports made in the discussion at the meeting by engineers showed the simplicity and success of the meter. Mr. C. L. Edgar, of the Boston Edison system, stated that he had 800 of the meters in service cared for by two men and three boys, the latter employed in collecting the meter cells; the total cost being perhaps $2500 a year. Mr. J. W. Lieb wrote from Milan, Italy, that he had in use on the Edison system there 360 meters ranging from 350 ampere-hours per month up to 30,000.

In this connection it should be mentioned that the Association of Edison Illuminating Companies in the same year adopted resolutions unanimously to the effect that the Edison meter was accurate, and that its use was not expensive for stations above one thousand lights; and that the best financial results were invariably secured in a station selling current by meter. Before the same association, at its meeting in September, 1898, at Sault Ste. Marie, Mr. C. S. Shepard read a paper on the meter practice of the New York Edison Company, giving data as to the large number of Edison meters in use and the transition to other types, of which to-day the company has several on its circuits: "Until October, 1896, the New York Edison Company metered its current in consumer's premises exclusively by the old-style chemical meters, of which there were connected on that date 8109. It was then determined to purchase no more." Mr. Shepard went on to state that the chemical meters were gradually displaced, and that on September 1, 1898, there were on the system 5619 mechanical and 4874 chemical. The meter continued in general service during 1899, and probably up to the close of the century.

Mr. Andrews relates a rather humorous meter story of those early days: "The meter man at Sunbury was a firm and enthusiastic believer in the correctness of the Edison meter, having personally verified its reading many times by actual comparison of lamp-hours. One day, on making out a customer's bill, his confidence received a severe shock, for the meter reading showed a consumption calling for a charge of over $200, whereas he knew that the light actually used should not cost more than one-quarter of that amount. He weighed and reweighed the meter plates, and pursued every line of investigation imaginable, but all in vain. He felt he was up against it, and that perhaps another kind of a job would suit him better. Once again he went to the customer's meter to look around, when a small piece of thick wire on the floor caught his eye. The problem was solved. He suddenly remembered that after weighing the plates he went and put them in the customer's meter; but the wire attached to one of the plates was too long to go in the meter, and he had cut it off. He picked up the piece of wire, took it to the station, weighed it carefully, and found that it accounted for about $150 worth of electricity, which was the amount of the difference."