Thunderstruck - Erik Larson [9]
As men developed a scientific outlook, they created devices that allowed them to generate their own sparks. These were electrostatic machines that involved the rubbing of one substance against another, either manually or through the use of a turning mechanism, until enough electrostatic charge—static electricity—built up within the machine to produce a healthy spark or, in the jargon of electrical engineers, a disruptive discharge. Initially scientists were pleased just to be able to launch a spark, as when Isaac Newton did it in 1643, but the technology quickly improved and, in 1730, enabled one Stephen Gray to devise an experiment that for sheer inventive panache outstripped anything that had come before. He clothed a boy in heavy garments until his body was thoroughly insulated but left the boy’s hands, head, and feet naked. Using nonconducting silk strings, he hung the boy in the air, then touched an electrified glass tube to his naked foot, thus causing a spark to rocket from his nose.
The study of electricity got a big boost in 1745 with the invention of the Leyden jar, the first device capable of storing and amplifying static electricity. It was invented nearly simultaneously in Germany and in Leyden, the Netherlands, by two men whose names did not readily trip from the tongue: Ewald Jürgen von Kleist and Pieter van Musschenbroek. A French scientist, the Abbé Nollet, simplified things by dubbing the invention the Leyden phial, although for a time a few proprietary Germans persisted in calling it a von Kleist bottle. In its best-known iteration, the Leyden jar consisted of a glass container with coatings of foil on the inside and outside. A friction machine was used to charge, or fill, the jar with electricity. When a wire was used to link both coatings, the jar released its energy in the form of a powerful spark. In the interests of science Abbé Nollet went on to deploy the jar to make large groups of people do strange things, as when he invited two hundred monks to hold hands and then discharged a Leyden jar into the first man, causing an abrupt and furious flapping of robes.
Naturally a competition got under way to see who could launch the longest and most powerful spark. One researcher, Georg Richman, a Swede living in Russia, took a disastrous lead in 1753 when, in the midst of an attempt to harness lightning to charge an electrostatic device, a huge spark leaped from the apparatus to his head, making him the first scientist to die by electrocution. In 1850 Heinrich D. Ruhmkorff perfected a means of wrapping wire around an iron core and then rewrapping the assembly with more wire to produce an “induction coil” that made the creation of powerful sparks simple and reliable—and incidentally set mankind on the path toward producing the first automotive ignition coil. A few years later researchers in England fashioned a powerful Ruhmkorff coil that they then used to fire off a spark forty-two inches long. In 1880 John Trowbridge of Harvard launched a seven-footer.
Along the way scientists began to suspect that the sudden brilliance of sparks might mask deeper secrets. In 1842 Joseph Henry, a Princeton professor who later became the first director of the Smithsonian Institution, speculated that a spark might not be a onetime burst of energy but in fact a rapid series of discharges, or oscillations. Other scientists came to the same conclusion and in 1859 one of them, Berend Fedderson, proved it beyond doubt by capturing the phenomenon in photographs.
But it was James Clerk Maxwell who really shook things up. In 1873 in his A Treatise on Electricity and Magnetism he proposed that such oscillations produced invisible electromagnetic waves, whose properties he described in a series of famous equations. He also argued that these waves were much like light and traveled through the same medium, the mysterious invisible realm known to physicists of the day as ether. No one yet had managed to capture a sample of ether, but this did not stop Maxwell from calculating its relative density. He came