Henry and Morse

  Joseph Henry, at Princeton University, conducted numerous experiments with induction, or the tendency of a primary electric current in a conductor to stimulate a secondary current in another conductor nearby. During one group of experiments in 1842, which Henry called "induction at a distance," he measured secondary current as far as 200 feet away from the primary circuit. Although the effects were more pronounced with the instantaneous discharge of a Leyden jar (electrostatic induction) at the primary circuit, they were also present when a continuous current passed through a coil (electromagnetic induction). Henry also noted that the wireless electricity seemed to oscillate, but he had no instruments sensitive enough to study this phenomenon. Neither Henry nor his students used induction for telegraphy, but his methods and results were well known to scientists on both sides of the Atlantic.

     In the same year, Samuel F.B. Morse, using different tech­nology, devised a working wireless telegraph. Having failed at submarine telegraphy when a ship's anchor hooked and cut the cable, Morse came up with a novel solution to the problem. By then, electricians knew how to use a natural conductor, like earth or water, as the return link to complete an electrical circuit. Morse reasoned that the same natural conductor could replace the wire in the link between transmitter and receiver as well. By attaching the ends of the wires leading from the battery and telegraph key to metal plates, doing the same with wires from a galvanometer, and then submerging the sets of plates on opposite banks, Morse successfully sent a message across a canal some 80 feet wide. The next year, 1843, his assistants sent messages a mile across the mouth of the Susquehanna River.

     Morse soon became preoccupied with building a wired tele­ graph system and never applied for a patent on the wireless scheme. About ten years later, however, James Bowman Lindsay, a Scottish school teacher, applied the same natural conduction technology to the task. Apparently Lindsay was unaware of Morse's prior work. By using larger metal plates spaced more widely apart, he increased transmission distance to two miles across the River Tay at Dundee. Lindsay received British patent 1,242 for this invention in 1854, but he failed to raise enough capital to build a prospective transatlantic installation.

Loomis and Ward

     American dentist Mahlon Loomis, of Washington, D.C., devised a wireless telegraph system using the upper atmosphere as one conductor, the earth as the other, and the difference in electric potential between the two as the power supply. In 1866 he raised two kites, attached to grounded wires, from mountains in northern Virginia and transmitted a signal between them, a distance of 18 miles. Loomis later adapted this apparatus for telegraphy and, he claimed, telephony. The most interesting facet of this invention was that it worked best when the kites were at the same altitude, leading some historians to speculate that Loomis had hit upon the principle of syntony, or tuned resonance. Although he received U.S. patent 129,971 in 1872, Loomis failed to get a requested appropriation from Congress, and several potential groups of investors went broke in the numerous financial panics that followed the U.S. Civil War.

     Another U.S. patent for wireless telegraphy, number 126,356, issued to William Henry Ward of Auburn, New ​​York, actually preceded the Loomis patent by three months. Ward was an author of religious tracts and a vigorous promoter of his own inventions, which included naval signal flags, bullet-making machines, bomb shell fuses, and pomade for the hair. Loomis had made Ward's acquaintance in the late 1850s when Ward agreed to take a set of Loomis-patented false teeth under consignment to a trade show in Europe. Because Loomis furnished no illustrations or model with his patent application, it is difficult to tell how much similarity existed between the two inventions. The Ward wireless telegraph, however, seems to be based on the absurd idea that convection currents in the atmosphere would carry the electric signal to the receiver. Neither system found a ready market.

     The 1870s were a busy decade for electricians, whether they were scientists, engineers, or tinkering inventors. Laboratories large and small sprang up in the United States and Europe for both educational and commercial purposes. The new professional societies, as well as academic and trade publications, facilitated communication, so electricians knew what other electricians were doing. Although there was scant progress in wireless telegraphy, there were several interesting events.

     Various experiments, including those by Elihu Thompson and Thomas Edison in the United States and by David Hughes in Great Britain, suggested the existence of electromagnetic waves, as predicted by James Clerk Maxwell. Edison called them the "etheric force." Hughes unwittingly built a complete radio system, with a sparking coil as a transmitter and a carbon microphone as a coherer, or receiver. He gave up these experiments, however, when directors of the Royal Society visited his lab to witness a demonstration and assured him that the effects were due to induction alone.

Wireless Telegraphy

     In 1878 Alexander Graham Bell attempted to build a Morse­ type wireless telephone using water as a natural conductor. He tested this device the next year with only limited success on the Potomac River near Washington, D.C. When he learned that John Trowbridge at Harvard was pursuing similar research, Bell dropped that idea in favor of one more promising-sending a voice signal on a beam of reflected light.

     With a thin diaphragm of reflective mica at the mouth­ piece, the device captured light waves from the sun, modulated the light as sound waves moved the diaphragm, and reflected the beam toward the receiver. The receiver was a parabolic reflector coated with silver and aimed at a piece of selenium, a natural photoelectric transducer. Once the selenium converted the light to electricity, the signal traveled to a regular telephone receiver. Bell called it the Photophone, received U.S. patent 235,199 in 1880, and exhibited the device widely in both the United States and Europe. Later experiments proved that the device worked with less expensive lampblack substituting for the selenium and with any form of radiant energy. The Photophone then became known as the Radiophone, the first application of the term radio to wireless communication.

     Although European electricians were captivated by the device, and Bell himself thought it a greater invention than the telephone, American Telephone and Telegraph (AT&T) saw no commercial possibility and soon ceased its development. The company continued to exhibit the Photophone as a novelty through the St. Louis World's Fair of 1904, but Bell was so disgusted that he gave his original model to the Smithsonian Institution and halted all active involvement with the company that had once borne his name and was based on his patents.

     Amos Dolbear, another early telephone pioneer, became interested in wireless telephony by accident. While working in his lab at Tufts College in 1882, he noticed that he was still hearing sounds from a receiver, even though the wire to the transmitter on the other side of the room was disconnected. Upon examination, he determined that the signal was traveling by electrostatic induction. Through experimentation, Dolbear built a wireless telephone system that employed grounded aerials at both transmitter and receiver and worked well at distances of up to a mile. He demonstrated the invention by transmitting both voice and music at scientific conferences in the United States, Canada, and Europe, receiving U.S. patent 350,299 in 1886. Dolbear's transmitter was capable of generating electromagnetic waves and was in many respects similar to Marconi's of a decade later, but the receiver lacked any device to detect radio waves. Dolbear never attempted to sell his wireless telephone.

     In Great Britain during the 1880s, both William Preece and Willoughby Smith developed functional wireless telegraphs to transmit across relatively short distances. They used both natural conduction and induction technologies to solve practical problems such as how to communicate with offshore islands and lighthouses and with workers in a coal mine. Preece, an engineer at the British Post Office, had been interested in wireless since he witnessed Lindsay's work in 1854. Later he became Marconi's chief advocate with the British government.

Moving Telegraphy

     The possibility of communicating instantly by telegraph with moving trains generated substantial interest in the United States. William Wiley Smith, a telephone office manager, devised an electrostatic wireless telegraph that used existing lines running beside the tracks and received U.S. patent 247,127 in 1881. Although Smith's invention did not work very well, his partner, Ezra Gilliland, was a childhood friend of Thomas Edison. Three years later, Gilliland convinced Edison to buy the patent, improve the technology, and promote it to the rapidly growing railroad industry as a safety and convenience appliance. Gilliland and Edison's interest in railroad telegraphy grew when they learned that another inventor, Lucius Phelps of New York, had just applied for a patent on a similar system. Phelps, moreover, was preparing to demonstrate a working model in New York City during February 1885. Edison quickly filed a new patent application based on improvements to the prior Smith patent. The Patent Office called the two applications into interference hearings. Meanwhile, Granville Woods, a black inventor from Cincinnati, filed still a third application for a railroad telegraph system. Once again, the Patent Office declared the Woods and Phelps applications to be in interference.

     In a series of hearings that ended in 1887, Woods was the ultimate victor. He proved that as early as 1881 he had shown sketches and models of his invention to friends in his neighborhood. Shortly thereafter, he lost his job and contracted smallpox, delaying his progress. After reading about the Phelps demonstration in Scientific American, he quickly gathered his old notes and models and went to his lawyer. In the meantime, the patent examiner determined that the Smith patent, controlled by Edison, had no priority because it used electrostatic induction, whereas the Phelps and Woods inventions used electromagnetic. After this ruling, Edison dropped out of the hearings and merged efforts with Phelps.

     Woods received several U.S. patents for his invention,beginning with number 371,241, and Phelps did likewise, starting with number 334,186. But all of this activity was in vain, for the railroads had no interest in wireless telegraphy at that time. With no laws compelling safety or emergency communication improvements, they saw the technology as an added expense without compensatory revenue. So none of the inventors profited. Eventually Edison modified his application and received U.S. patent 465,971 in 1891. He sold the patent to Marconi some years later for a nominal sum. After the failure to market the railroad telegraph, interest in wireless waned in the United States until after Marconi brought his system to the America's Cup races of 1899.

     In a widely read article of 1891, John Trowbridge concluded that the technologies of Henry and Morse were inefficient for long-distance wireless communication and, with no tuning mechanism, were limited to a single message at a time. The last champion of natural conduction and induction wire­ less was probably Nathan Stubblefield, a farmer from Ken­tucky who learned about electricity by reading Scientific American and Electrical World. Stubblefield demonstrated an induction wireless telephone for neighbors as early as 1892. He generated considerable publicity in 1902 with a natural conduction wireless telephone that he displayed to enthusiastic crowds in Washington, D.C., and Philadelphia. One remarkable feature of this system was its ability to broadcast a signal to multiple receivers simultaneously. Stubblefield intended to use it to disseminate news and weather information, but he was the victim of a stock fraud scheme that left him destitute. By the time he received U.S. patent 887,357 in 1908 for his induction system, superior technology existed. But he became very paranoid that others were seeking to profit from his work, and he eventually died of starvation in 1928.

Landell and Tesla

     Two other inventors had the opportunity to develop wireless communication by electromagnetic waves prior to Marconi but failed to do so. Roberto Landell de Moura, a Catholic priest from Brazil, studied physics at the Gregorian University in Rome while he prepared for the priesthood. When he returned to Brazil in 1886, Landell set up a laboratory and began electrical experiments. His interest turned to wireless. He built acoustic telephones, a model of Bell's Photophone, and, soon after he learned of Hertz's and Branly's work, his own electromagnetic wave transmitter and receiver. Then he combined the three into one multifunction wireless telephone system. By 1893 Landell was sending messages over a distance of five miles. Then, two years later, a powerful bishop witnessed a demonstration. He was so unnerved by the voices coming from nowhere that he declared the apparatus the work of the devil and ordered Landell to stop his work.

     Shortly thereafter, fanatics broke into Landell's laboratory, destroyed the apparatus, and set fire to the building. It took Landell five years to regroup, but he eventually received Brazilian patent 3,279 in 1900 and traveled to the United States to pursue patents and development. Hampered by poor legal advice, illness, and inadequate knowledge of the U.S. patent system, Landell nevertheless persisted and received three U.S. patents, beginning with number 771,917 in 1904. By then Marconi and others controlled the market for radio.

     Like Landell, Nikola Tesla was trained in physics at a European university. He came to the United States in 1884 to work first for Edison and then for Westinghouse. In his work with high-frequency alternating currents, Tesla discovered that the alternators also generated continuous electromagnetic waves that could be used to transmit signals. He demonstrated this phenomenon as early as 1891 but made no practical application of it until he built a radio-controlled toy boat, for which he received U.S. patent 613,809 in 1898. The next year, he established a laboratory in Colorado Springs, Colorado, from which he intended to send wireless messages to an international exposition in Paris in early 1900. But in the midst of his radio experiments, Tesla became fascinated with the possibility for wireless distribution of electric power through the earth itself and devoted most of the rest of his life to devising methods to accomplish that goal.