One of the most important discoveries in the
last 400 years has been electricity. You may ask, "Has electricity been
around that long? The answer is "yes", and perhaps much longer.
Surprisingly, electricity only became useful to humanity in the late 1800s.
The earliest known methods of generating electricity were by creating a static
charge. Alessandro Volta (1745-1827) invented the so-called "electric
pistol" by which an electrical wire was placed in a jar filled with methane
gas. By sending an electrical spark through the wire, the jar would explode.
Volta then thought of using this invention to provide long distance
communications, albeit only one Boolean bit. An iron wire supported by wooden
poles was to be strung from Como to Milan in Italy. At the receiving end, the
wire would terminate in a jar filled with methane gas. On command, an electrical
spark is sent by wire that would cause a detonation to signal a coded event.
This communications link was never built.
The next stage of generating electricity was through electrolysis. Volta
discovered in 1800 that a continuous flow of electrical force was possible when
using certain fluids as conductors to promote a chemical reaction between
metals. Volta discovered further that the voltage would increase when voltaic
cells were stacked. This led to the invention of the battery.
From the availability of a battery, experiments were no longer limited to a
brief display of sparks that lasted a fraction of a second. A seemingly endless
stream of electric current was now available.
In the early 1800, France was approaching the height of scientific advancements
and new ideas were welcomed with open arms to support the political agenda. By
invitation, Volta addressed the Institute of France in a series of lectures in
which Napoleon Bonaparte was present. Napoleon himself helped with the
experiments, drawing sparks from the battery, melting a steel wire, discharging
an electric pistol and decomposing water into its elements.
In 1802, Dr. William Cruickshank designed the
first electric battery capable of mass production. Cruickshank arranged square
sheets of copper soldered at their ends, intermixed with sheets of zinc of equal
size. These sheets were placed into a long rectangular wooden box that was
sealed with cement. Grooves in the box held the metal plates in position. The
box was filled with an electrolyte of brine, or watered down acid.
New discoveries were made when Sir Humphry Davy installed the largest and most
powerful electric battery in the vaults of the Royal Institution of London. He
connected the battery to charcoal electrodes and produced the first electric
light. Witnesses reported that his voltaic arc lamp produced "the most
brilliant ascending arch of light ever seen."
All batteries at this time were primary cells, meaning that they could not be
recharged. In 1859, the French physicist Gaston Planté invented the first
rechargeable battery. This secondary battery was based on lead acid, a chemistry
that is still used today.