In the 19th century the word "technology" had not become popular, and the catchword for material and industrial progress was "invention." The inventor was worthy of popular esteem and his "ingenuity" was within reach of anyone. Someone who had no technical education nor mathematical skills, like Thomas A. Edison, could and did invent useful and clever things and earn the title of "wizard." Edison, however, was also a transitional figure to the new technology for he employed the "invention factory" and its resources to produce inventions which his contemporaries such as Swann could not match. He brought the stock ticker, the quadruplex telegraph, the carbon transmitter for the telephone, and the phonograph into being, and these opened financial backing which made possible the "invention factory of Menlo Park." After he visited William Wallace's shop in Anonia, Connecticut in 1878, Edison was inspired by the electric generator and arc lighting he saw there, and by the vision of harnessing the power of Niagara Falls to the uses of electric power and light.

Edison began his electric light experiments confident that the solution to the problem lay in developing a regulator to prevent the filament of the electric light from melting. He used his experience from telegraphy to either divert or interrupt the current from the incandescing filament. His ingenious devices to regulate proved to be a blind alley and the effort was abandoned after much work.

Carbon as an element was impossible to protect from combustion in air, and vacuum was yet to be tried. Moses G. Farmer, who was himself experimenting with an incandescent lamp, sent Edison a small bar of iridium as a light emitter and Farmer suggested that carbon however "is the most promising when sealed tightly from oxygen in a vacuum or in nitrogen." Edison was spurred on to try iridium in air and ignored the other advice on carbon. Platinum was also tried, but both proved impractical for the absorption of gases from the surrounding environment, and this led Edison to try to minimize this by placing the filament in a vacuum. Vacuum pumps, however, were in a crude state, and effort was directed to improve a vacuum pump using a column of mercury, as was the state of the art, to obtain better vacuums for the filament.

The arc light was a series circuit and required a generator and circuit large enough to deliver a high and constant current. The light intensity would vary with change in the number of lights in the same circuit. Edison deduced that the filaments of the electric light should be high resistance and be connected in parallel, and the generator supply would be of constant voltage with varying current. This would depend upon the number of lamps to be supplied. The parallel system would also require a new type of generator, and the effort was begun to produce one. Along with the parallel circuit, the Edison system method was to use separate feeder circuits to a group load rather than a single large main supply, and to employ a three-wire system. To complete the engineering program, an underground conductor network, devices for maintaining constant voltage, safety fuses, light sockets with on-off switches, and meters to measure electrical use were developed.

The stage was set for the invention of the first successful incandescent light. A direct current generator in which both the armature and the field were electromagnet, could produce a constant relatively high voltage with 90 percent efficiency had been developed. Improvements in vacuum pumps enabled these to draw a vacuum of 0.00001 atmospheres within the lamp. This had to be maintained when gas trapped within the incandescing material escaped following the heating of the material, and furthermore, the glass envelope must be effectively sealed around the lead wires to ensure the retention of the high vacuum. The design of a high resistance filament which could be used in a parallel circuit was right. Edison and the Menlo Park crew returned to carbon for the filament material, possible because it was learned that Swann was working with it in England. The combination of carbon and a vacuum had been tried by no less than ten other inventors, beginning with the Belgian Jobard in 1838, without success.

The incandescing material had to be heated electrically until it glowed brightly enough to be tolerable to the eyes, and be comparable in cost and brightness to its main competitors, the gas jet and the oil lamp, and it must not melt.

In October 1879, Edison was sitting in his laboratory abstractedly rolling a piece of compressed lampblack between his fingers until it had become a slender filament (slender was a part of producing a high resistance). He happened to glance at it and the idea occurred to him that it might be the answer. It was tried as an incandescent filament within a vacuum glass bulb and produced good results. After further experiments with altered forms, the conclusion was reached that a form of carbon as a filament was the right answer.

One of Edison's assistants was Frances R. Upton who had received a college education and had training in physics at Princeton University and in Berlin with Helmholtz. This was his description of the successful filament: "The filament is a charred paper cut in thread-like form. Horse shoe shaped loops are cut from cardboard and placed in layers within an iron box, with tissue paper between the loops. The box is hermetically sealed and heated until it became red. The carbon loops and the carbonized tissue paper are found to be perfectly homogenized in structure, and both elastic and tough."

Just four years after Edison began the work on the electric light, on September 4, 1882, Pearl Street Station in lower Manhattan began supplying electric power and light to its customers, and continued to do so with only three hours of interrupted service until January 2, 1890.

Modern electric light and power systems, however, would not be three wire direct current with limited geographic reach, but the single and three-phase alternating current of Westinghouse, Tesla, and Steinmetz, but Edison had provided the foundation.