Electricity and the second industrial revolution

At three in the afternoon on 4 September 1882, Edison’s Pearl Street station in New York began supplying electricity to about 400 lamps.

A second wave

Historians often speak of a second industrial revolution, from about 1870 to 1914. The first had been built on coal, iron, steam and cotton, and Britain had led it. The second was built on cheap steel, electricity, chemicals, oil and the internal combustion engine, and its leaders were Germany and the United States. Science mattered more than before: many of the new industries grew out of laboratory discoveries, and large companies began hiring trained scientists and engineers to invent on purpose.

Steel for everything

Steel is iron with a small, controlled amount of carbon. It is stronger and tougher than cast iron, but before the 1850s it was expensive and made in small batches, used for blades and tools rather than bridges. In 1856 Henry Bessemer in England patented a process that blew air through molten pig iron. The oxygen burned out the impurities, and the heat of that burning kept the metal molten without more fuel. The American William Kelly had experimented with the same idea, but Bessemer turned it into a commercial success. Cheap steel replaced iron in railway rails, ships, bridges and the frames of the first skyscrapers.

From magnets to power stations

In 1831 Michael Faraday showed the Royal Society in London that moving a magnet near a coil of wire produces an electric current. That principle, electromagnetic induction, is how almost every generator works. By the 1870s engineers had built practical dynamos. On 7 March 1876 Alexander Graham Bell received US patent 174,465 for the telephone, and three days later he called his assistant Thomas Watson with the words “Mr. Watson, come here, I want to see you.” Thomas Edison’s team in New Jersey worked on a long-lasting electric light bulb and, more importantly, on a whole system to supply it: generators, cables, meters and switches. On 4 September 1882 the Pearl Street station in lower Manhattan, driven by coal-fired steam engines turning six large dynamos, began supplying a district of about a quarter of a square mile. It started with fewer than 90 customers and about 400 lamps; within a year it served 513 customers and about 10,000 lamps.

Engines, cars and the moving line

Engines that burned fuel inside a cylinder were lighter than steam engines and could start at once. On 29 January 1886 Carl Benz in Mannheim applied for a German patent, number 37435, for a three-wheeled carriage driven by a petrol engine; it is often called the birth certificate of the car. Cars stayed expensive until Henry Ford set out to build one that ordinary families could buy. In October 1913, at his Highland Park factory in Michigan, Ford introduced a moving assembly line: instead of workers walking around a car, the car moved past workers who each did one task. The time to assemble a Model T fell from 12.5 hours to 93 minutes. The price fell with it, from $850 in 1908 to $490 in 1914 and $260 in 1924, and by 1927 more than 15 million had been sold. The same method spread to other industries, along with the repetitive, closely timed work that came with it.