Most students of electrical engineering, and that includes practising engineers, know precious little about its history. Many see no need to know about the past and may agree with Henry Ford’s famous quip that history is bunk, despite the observation that since the quip itself has now passed into history it must presumably also be regarded as bunk. Maybe they view the history of their subject as old hat and irrelevant to our modern understanding. If that is the case, they are at odds with some of the men who made the most important contributions to their chosen subject of study.
“At this point, I will set out to explain what law of nature causes iron to be attracted by that stone which the Greeks call from its place of origin magnet, because it occurs in the territory of the Magnesians.”1 So began the Roman poet Lucretius some 2000 years ago when he expounded his theory of magnetism, a theory to which some 17th century theories bore vague resemblance.
In his book published in 1600 William Gilbert dismissed Porta’s theory of magnetism as “the ravings of a babbling old woman.” Porta replied that Gilbert was “an Englishman with barbarous manners.” Most scientists today when in disagreement with each other are a little more polite than that, at least in public. Despite their mutual condemnation both Gilbert and Porta are remembered for their contributions to experimental magnetism and for their (to modern ears) quaint theories. No theory of magnetism, however, whatever its weakness or strength, could begin to approach the truth as we know it while magnetism and electricity were regarded as separate, even if similar, phenomena. When the discovery of the united phenomenon of electromagnetism was announced by Oersted in 1820 a whole new world was opened for scientific exploration and the ground rules of our electrical science and engineering were made.
By 1980 the world’s annual generation of electrical energy was almost 8 × 1012 kilowatt-hours. It was produced by exploitation of electromagnetic induction, a scientific effect discovered in 1831. Until then anyone who wanted to use electricity had to use batteries or friction generators, or even electric eels. Even long after 1831 dynamos exploiting induction were only used on a tiny scale, mostly for experiments.
Leaflets published around 1843 advertised a new commercial venture, a ‘galvanic and magneto electric telegraph.’ This, the world’s first commercial electric telegraph, went into operation in 1839 on the Great Western Railway in England. A telegram, or rather a telegraphic despatch, cost a shilling (5p), and could be sent thanks to the work of William Cooke and Charles Wheatstone. Members of the public were allowed to view the equipment, again on payment of a shilling, and the Morning Post recommended the visit to all who loved to see the wonders of science.
The electrical engineering industry really began life as an industry to provide electric lighting, first by means of arc lamps and then by incandescent lamps. The industrial applications of electricity before the commercial exploitation of electric lighting were trivial compared with what came after. The telegraph, telephone, and electroplating had raised small industries to develop, install, maintain, and run those services, and the communications industry has grown into an enveloping giant in its own right. But it was lighting that first demanded central power stations for the efficient mass generation of electric current and then placed that current in the home, office, factory, and street for use in lighting systems, and later for other applications as well. In this way, and others, lighting had a profound effect on the technical and commercial development of the industry, including even electronics. Further, it was the profits from electric lighting that supported the electrical industry in its formative years and enabled some of the early companies (for example General Electric in America and Philips in the Netherlands) to grow into large industrial concerns operating internationally in most of the major areas of electrical engineering. Even today the profits from light bulbs are important to major firms.
No branch of the history of electrical engineering has been studied and written about more widely than electrical power. Several good sources discuss the subject in more detail than can be achieved here.1-4 Only an outline sketch is attempted in this chapter, with details of just some of the origins.
The quest to apply electromagnetic waves to communications is a little less than 100 years old; yet it has brought incredible changes to our way of life. Radio and its uses have continued to hit the headlines from its earliest days. Whether the story described experiments by Hertz, the arrest of Dr. Crippen, the rescue operation for the Titanic, the bombing of Pearl Harbor, the arrival of television, or men walking on the moon, it was followed avidly by the people of the day and brought to them by our mastery of electromagnetic radiation. In this chapter we shall attempt to review the highlights of the development and use of radio from the first radiotelegraphs, through wireless and the beginnings of electronics, to radar, television, and other present-day applications of the radio art. As in other chapters, some things will have to be left out if we are to cover the era from the early struggles to communicate across a few feet to the use of radio in an optimistic attempt to search for extraterrestrial life. Yet it is hoped that the chapter will present an informative summary of the development of radio in its most important forms.
This chapter ties up a few loose ends. It aims to show how some of the theories and discoveries that helped shape modern electrical engineering were made. Not all the important theories or discoveries are included but many of them are. They include the discovery of the electron and the question of its nature, which leads us into quantum theory; modern magnetism, a subject that was almost removed from the sphere of interest of most electrical engineers until rejuvenated by the interest in magnetic bubble memories; communication theories and the path towards Shannon’s information theory, which includes advances in circuit and network theories and the invention of filters and the negative-feedback amplifier; and the development of our system of units. Justice cannot be done to any of these topics in such a short space but, it is hoped, the basic story can be put across.
Miniaturization has made it possible for electronics to penetrate society more widely and deeply than ever before. Pocket calculators, electronic watches, miniature colour television receivers and the like are only some of the examples of the miniaturization of electronics of which the general public first became aware. Even before they came along, miniaturized electronic systems had made a significant impact in military, industrial, and commercial areas. Miniaturization helped in the exploration of space, in communications, in the control of machinery and processes, and in the handling and processing of data. The miniaturization of electronics is sometimes regarded as a somewhat late development that derives from the integrated circuit; yet miniaturization on the grounds of size, weight, and power requirements was under way long before the integrated circuit was invented and even before the transistor became commercially available. Valve (vacuum-tube) manufacturers were remarkably successful in producing miniature and subminiature valves, some of them smaller than a present-day power transistor; and the screen printing of resistive and other passive components, and the concept of electronic modules, helped to bring about smaller electronic systems. Yet the big acceleration towards microelectronics did indeed begin with the invention of the integrated circuit, when at first small and later large circuits were formed on a single chip of silicon. The net result was systems far larger and far more complex than could even have been dreamed of before.
The definition of a computer given by Webster’s dictionary was changed in 1955 from ‘one who performs a computation,’ to ‘one or that which performs a computation.’ The addition of three words reflected a change in mankind’s methods of manipulating numbers that was to have many widespread yet unforeseen effects. The human computer, and his mechanical calculator, had been joined by the electronic computer.
If we accept that technology concerns mankind’s methods of doing or making things, then from the time that men first used stones to kill in order to eat they have lived in societies in which technology has played a role.1 The importance of that role has increased slowly through the centuries. The arm that threw the stone was eventually aided by a sling; the stone gave way to a spear. The bow and arrow became dominant. Guns fired bullets, howitzers hurled shells, and now intercontinental ballistic missiles carry nuclear bombs. At whatever time we consider in the history of the human race men have been using technology and the technology has been changing. However, for most of our history the rate of change has been very slow, perhaps barely perceptible. The effects of the changes were probably felt as isolated events separated by many years in which little or nothing altered.
