Electrical Discoveries

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Electrical Discoveries

Even before the end of the eighteenth century a certain amount of research had gone on in this field, but the experimenters had only achieved the construction of various frictional machines, which allowed the study of static electricity but no more, and the observation of lightning, which had got them no further than the invention of lightning conductors.

In 1800, however, the Italian Volta discovered the principle of the voltaic cell, the first means of creating an electric current and prototype of our modern batteries, and a few years later Humphry Davy, carrying on from where Volta had stopped, discovered first electrolysis and then the voltaic arc, i.e.

the spark between the terminals of a voltaic battery - a discovery containing the germs not only of are lighting but of the electric furnace.

These discoveries bore no immediate practical fruit; it was not until 1848 that devices for adjustment finally made arc lighting a possible proposition.

The year 1820 saw great theoretical advances in four countries - Denmark, France, Germany and England.

Oersted of Copenhagen University arrived after long study on the relation between magnetism and electricity, and incidentally, though he took no steps in the matter, at the principle of the telegraph; Ampere, in Paris, worked out the theory of magnetism in full, and Ohm, at Munich, the theory of currents; while in England Sturgeon constructed the first electromagnet and Faraday, by his discovery of electrical induction, laid the scientific foundation for all that part of the electrical industry which is concerned with dynamos and motors.

Progress in Telegraphy.

Practical money-making application of these principles did not come for some time. The first use of the new power was in telegraphy. By 1868 there were 16,000 miles of telegraph wires in the country; in 1870 the company concerned was bought out by the Government, and the service was run thereafter as a part of the Post Office. The developments which took place in speed of transmission, in the multiple use of a single wire, and in the improvement of recording messages, need hardly be described in detail.

Dynamos, Commutators and Motors.

The use of electricity for light and power came later. The earliest dynamos, based on Faraday's principle, were no practical use; they produced a feeble and fluctuating current, and there was no means of tapping it. They were improved and made more powerful by successive experimenters in many different countries - Gramme, of the famous "Gramme Ring ", in which an armature revolving between electromagnets generated current through a commutator; Siemens, later to win fame with his electric furnace; and Alteneck. More than any other, the electrical industry is international in its origins. During the 1870's, forty years after Faraday's original discovery, dynamos began to be used for supplying current for street lighting and lighthouses;. and in 1879 Edison, in the United States, began his pioneering work in the field of public electricity supply. Simultaneously it was discovered (according to legend, quite accidentally) that the principle of the dynamo was, so to speak, reversible; a rotary movement, in the dynamo, generated a current; but a current could equally well generate a rotary movement, and so serve as a motive power. The way was open for the development of the electric motor, with all that that implies to industry.

Lighting.

Improvements followed rapidly in the next decade, both in the actual generation of current and in its transmission and use. The first electrical lighting was by carbon arc lamps, which gave a powerful light, but had serious disadvantages; the carbons were always getting out of adjustment, and their combustion generated fumes. For this reason, and also because of the high voltages required, they were only suitable for street lighting. Before electricity could be brought into people's homes a new principle had to be introduced--that of the incandescent lamp, perfected by Edison in 1880, in which light was given off not by a spark but by a resistant material raised to white heat by the passage of the current. Also, the deadly voltages of the transmitting cables had to be "stepped down" by the use of transformers. These worked on the principle of induction, and were developed between 1885 and 1890.

Furnaces.

The principle of the arc lamp, meanwhile, was not only embodied in lighting systems; it was applied to furnace-building. The electric furnace, though more expensive to run than one heated by coal or coke, had advantages which made it a serious rival in some fields. It required no chimney, it generated no waste gases, and, most important of all, its temperature could be far more delicately controlled - a vital point in the making of high-grade alloy steels. It is only the extremely high temperature. and delicate control of electrothermal apparatus which makes possible the fixation of nitrogen from the air, or the manufacture of carborundum; while these same properties, combined with electrolysis, are the essential features of the manufacture of aluminium. Thus - to look ahead a little - electric heating made possible the development of aviation.


Next Step: Charter Rights

TECHNICAL CHANGE, 1830-2004

AFTER the coming of the steam-engine technical progress entered, broadly speaking, on a new phase.

There is a clearer and clearer division to be found, from the 1830's on, between the inventor and the manufacturer; in the eighteenth century they were usually one and the same person, manufacturers turned inventor as the economic problems of their trade forced them to it.

The Darbys of Coalbrookdale, Crompton, Huntsman, were men of this sort; Watt and Arkwright mark an intermediate type, inventors turned manufacturer to exploit their own processes.

Later we find the actual manufacturers... see: TECHNICAL CHANGE, 1830-2004


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