Page 286 - Encyclopedia Of World History

636 berkshire encyclopedia of world history

Volta’s voltaic pile for producing a current of electricity.
The pile consists of alternating disks of different metals such
as copper and zinc separated by flannel or pasteboard
moistened with salt water or a dilution of sulphuric acid.

the general public, and scientists in particular, had steady electric power and transmit it to
and reliable access to an electrical current over an cities like New York. Westinghouse
extended period of time. collaborated closely with the Ser-
The Danish physicist Hans Christian Oersted (1777– bian physicist Nicola Tesla (1856–
1851) found that electrical current would deflect a mag- 1943) in the development of an
netic needle, thus establishing the discipline of electro- electrification system based on alter-
magnetism. The basic mathematical equations of elec- nating current (AC). This advance
tromagnetism were developed by André-Marie Ampère led to long discussions with the sup-
(1775–1836) in 1820s. porters of direct current (DC) like Edison, but finally alter-
In 1826 Georg Simon Ohm (1787–1854) proposed nating current prevailed.
the law defining the resistance of metallic conductors.
During the same decade Michael Faraday (1791–1867) The Twentieth
impelled electromagnetism even further by building the Century
first electric motor, transforming electric energy to kinetic During the twentieth century the use of electricity became
energy. In addition, Faraday’s theoretical proposal about fundamental in the lives of western societies, but it is no
dynamic lines provided a foundation for the Scotsman less important for the developing world.The continuous
James Clerk Maxwell (1831–1879), who in 1856 wrote increase in the need for electricity led to the establishment
the essay “On Faraday’s Lines of Force,” establishing in of nuclear-powered electric stations and the establishment
pure mathematical language the new subject of field of huge dams to collect the necessary quantity of water
physics, unifying magnetism, electricity, and light. for use in hydroelectric plants. One of them, for example,
Maxwell’s laws of electrodynamics were important for the the Aswan High Dam in Egypt, changed the whole eco-
development of many useful applications during the nomic and social profile of the country. During the last
twentieth century like electric power stations, radio, tele- decades of the twentieth century alternative sources for
vision, and even the computer. the production of electricity became more popular.
But before these applications came the electric tele- Among them solar energy and wind energy are the most
graph, invented by Samuel Morse (1791–1872) around widely used. In countries with high tides like England
1840, which caused a real revolution in communications. and France, these are also used for the production of
After Morse, Thomas Edison (1847–1931) became electricity.
famous for his electric lamp, not to mention his many There is no doubt that civilization as we know it
other inventions, like the phonograph. Carbon arc lamps could not exist without electricity, yet we must not forget
were used around the world extensively until the late that electricity is a product of that civilization.Therefore,
1970s, but the invention of the incandescent filament it is necessary for people to secure the use of electric
lamp by the Englishman Joseph Swan (1828–1914) in energy in the future by constructing the necessary facto-
1878 and by Thomas Edison in 1879 in the United ries and networks, having always in mind that oil and car-
States reduced their use dramatically in the years to bon will not last forever and that sun, water, and air can
follow. provide cheaper and more environmentally friendly
As the usefulness of electricity was recognized by soci- sources for the power supply we need.
ety, the need for electric power started to become
George N.Vlahakis
immense. Carbon, oil, and waterfalls became the main
sources for the energy needed. In 1896 George West- See also Computer; Energy; Industrial Technologies; Tele-
inghouse (1846–1914) used Niagara Falls to produce graph and Telephone