The Voltaic Pile and its Consequences

The next great step forward can be attributed to Alessandro Volta, who in 1799, following close upon the discovery of the galvanic effect by Galvani, built the first electric battery. This immediately became known as Volta's Pile and, like many other batteries which followed it, employed copper as an active element. It actually comprised discs of copper and zinc placed one upon the other, with a layer of wet cloth between each pair. The adoption of wet cloth as a separator was a fortunate afterthought, for although Volta himself believed that the current flow arose from the contact of the metals and not from any chemical action, the part played by an electrolyte in the action of a cell had yet to be discovered. This phenomenon in fact started a controversy which lasted throughout the 19th Century, with giants such as Kelvin supporting Volta's point and Michael Faraday favouring the chemical view.

The potentialities of this new source of energy were quickly realized and battery design was soon improved by Cruickshank, also by the many-sided Wollaston and Sir Humphrey Davy. In 1809 John Children constructed a battery having twenty pairs of copper and zinc plates, each plate being 6 ft long and 2 ft 8 in. wide; thus it involved 320 sq. ft of copper and had a total cell capacity of 945 gallons. John Children used this huge apparatus in further experiments to determine which was the best electrical conductor. In the same year Davy aimed still higher. He was the Professor at the new Royal Institution and he succeeded in inducing his patrons to provide funds for building a battery that had 2,000 pairs of copper and zinc plates, with a total surface area of 890 sq. ft. The first experiment with this great battery enabled him to produce an electric arc between carbon electrodes.

Among the most important applications which followed the construction of these large batteries was the electric telegraph. This was a landmark in the development of communications and also created a tremendous demand for copper wire.