In 1876 the American technological genius and rags-to-riches folk hero Thomas Alva Edison (1847–1931) set up the world’s first industrial research laboratory in the remote hamlet of Menlo Park, New Jersey. During the six years he and his team worked there he secured patents for scores of inventions, including the phonograph, the telephone (an improvement on Alexander Graham Bell’s invention), the electric pen (a stencil duplicator), and the electric light bulb. Incandescent electric light had been the despair of inventors for fifty years, and, as one of the Menlo Park assistants Francis Jehl recalls, Edison spent fourteen months searching for a suitable filament.

The hunt was a long, tedious one. Many materials which at first seemed promising fell down under later tests and had to be laid aside. Every experiment was recorded methodically in the notebooks. In many there was simply the name of the fiber and after it the initials ‘T. A.,’ meaning ‘Try Again.’

Literally hundreds of experiments were made on different sorts of fiber; for the master seemed determined to exhaust them all. Threads of cotton, flax, jute silks, cords, manila hemp and even hard woods were tried.

Some of the fibers being worked at the moment were piled conveniently on top of the chest; and today you may see them still in the same spot. Others were stored in jars along the shelves. An examination of the labels on the jars as they stand today on the shelves along the east wall of the restored laboratory will give an idea of what an infinite variety were examined.

Chinese and Italian raw silk both boiled out and otherwise treated were among those used. Others included horsehair, fish line, teak, spruce, boxwood, vulcanized rubber, cork, celluloid, grass fibres from everywhere, linen twine, tar paper, wrapping paper, cardboard, tissue paper, parchment, holly wood, absorbent cotton, rattan, California redwood, raw jute fiber, corn silk, and New Zealand flax.

The most interesting material of all that we used in our researches after a successful filament was the hair from the luxurious beards of some of the men about the laboratory. There was the great ‘derby,’ in which we had a contest between filaments made from the beards of [John] Kruesi and J. U. Mackenzie, to see which would last the longer in a lamp. Bets were placed with much gusto by the supporters of the two men, and many arguments held over the rival merits of their beards.

Kruesi, you know, was a cool mountaineer from Switzerland possessed of a bushy black beard. Mackenzie was the station master at Mt. Clemens, Michigan, who had taught telegraphy to the chief in the early days after the young Edison had saved the life of Mackenzie’s small son Jimmy. His beard, or rather, his burnsides, were stiff and bristling.

As I now recall, he won the contest, though some claimed that an unfair advantage was given him; that less current was used on the filament made from his beard than on that from Kruesi’s. Be that as it may, both burned out with considerable rapidity.

Edison’s electric light, incredible as it may appear, is produced from a little piece of paper – a tiny strip of paper that a breath would blow away. Through this little strip of paper is passed an electric current, and the result is a bright, beautiful light, like the mellow sunset of an Italian autumn.

‘But paper instantly burns, even under the trifling heat of a tallow candle!’ exclaims the sceptic, ‘and how, then, can it withstand the fierce heat of an electric current.’ Very true, but Edison makes the little piece of paper more infusible than platinum, more durable than granite. And this involves no complicated process. The paper is merely baked in an oven until all its elements have passed away except its carbon framework. The latter is then placed in a glass globe connected with the wires leading to the electricity producing machine, and the air exhausted from the globe. Then the apparatus is ready to give out a light that produces no deleterious gases, no smoke, no offensive odors – a light without flame, without danger, requiring no matches to ignite, giving out but little heat, vitiating no air, and free from all flickering; a light that is a little globe of sunshine, a veritable Aladdin’s lamp. And this light, the inventor claims, can be produced cheaper than that from the cheapest oil.

Edison’s laboratory was tonight thrown open to the general public for the inspection of his electric light. Extra trains were run from east and west, and notwithstanding the stormy weather, hundreds of persons availed themselves of the privilege. The laboratory was brilliantly illuminated with twenty-five electric lamps, the office and counting room with eight, and twenty others were distributed in the street leading to the depot and in some of the adjoining houses. The entire system was explained in detail by Edison and his assistants, and the light was subjected to a variety of tests. Among others the inventor placed one of the electric lamps in a large glass jar filled with water and turned on the current, the little horseshoe filament when this submerged burned with the same bright steady illumination as it did in the air, the water not having the slightest effect upon it. The lamp was kept thus under water for four hours. Another test was turning the electric current on and off on one of the lamps with great rapidity and as many times as it was calculated the light would be turned on and off in actual household illuminations in a period of thirty years, and no perceptible variation either in the brilliancy, steadiness or durability of the lamp occurred.