



‘Pylons, those pillars

Bare like nude, giant girls that have no secrets'







I was only one year old when Spender's poem was written but pylons were not part of my childhood or early manhood (nor were nude girls, come to think of it). I was brought up in a part of rural Wales which no- one thought worth supplying with electricity. Our lucubrating, such as it was, relied on candles, single and double wick oil lamps, and then, joy unconstrained, oil lamps with Welsbach's incandescent mantles. Incidentally, it was Welsbach's invention, together with an efficient gas industry, which set back Britain's adoption of electric lighting by a decade or more, and gave our foreign competitors such an advantage.

Ironically enough, I spent my working life employed by electrical companies, where I became interested in the early history of electrical supply, particularly the conflict between the advocates of one or other of the two supply systems - alternating current (AC) and direct current (DC).

Thomas Edison vs George Westinghouse

Thomas Edison was a fanatical supporter of the latter. His power plants invariably consisted of DC generators which supplied 110 volts DC all the way from producer to consumer. However, with such a low voltage, the maximum supply distance was only about two miles. His US rival, George Westinghouse, had cunningly purchased the American rights to Gaulard and Gibbs' AC transformers and acquired the patents rights for Tesla's AC polyphase system. Well prepared, he started to construct AC power stations capable of reaching customers over a wide area.

The great advantage of AC is that its voltage can be stepped up to a high level in a transformer with corresponding reductions in the current level (I). As the power lost in transmission lines is proportional to I2R, where R is the resistance of the cable, long transmission distances can be achieved - sufficient for a hydro-station at Niagara Falls to supply the town of Buffalo, for example. A single station would be capable of meeting all the electrical needs of a large city.

The origins of the electric chair

Edison thought AC supplies were unsafe and consequently launched a campaign to discredit Westinghouse. A former employee of his, ‘Professor' Harold Brown, persuaded the New York State Prison authorities to adopt electrocution as a ‘humane' means of carrying out capital punishment. Brown arranged for the purchase of three Westinghouse alternators to fulfil this task. What he was advocating, of course, was the electric chair, and there were even attempts to persuade the authorities to call it ‘The Westinghouse Chair'. The general idea being to associate Westinghouse's AC system with the horrors of execution and thus create a negative image in people's minds. (There are parallels here with ones inability to discuss the virtues or otherwise of nuclear electricity without generating images of Hiroshima and Nagasaki).

William Kemmler was the first man to be executed in the electric chair. The initial attempt was unsuccessful so the process had to be repeated at a higher voltage until the poor man was successfully killed. Incidentally, the date of his execution was 6 August 1890, the day now designated as ‘Hiroshima Day', and, even more weirdly, the day I happen to be writing this piece. There could be a message here but I don't know what it is.

Next month I hope to discuss how inadequacies in Britain's electricity system put us at a severe disadvantage during the First World War and how an international grid of high voltage DC might help combat global warming.

Further information:

The Pylons, (pdf file 13KB) Stephen Spender

Biography of Thomas Edison

Biography of George Westinghouse