In 1872 science was on the verge of several revolutions, but in daily life people felt mainly a smug self-confidence. The physics derived from Newton’s laws of motion (1687) appeared elegant and complete, seeming to demonstrate that God was the Perfect Watchmaker. Steam power, coal gas, and efficient combustion were well understood. The latest addition to the toolbox had been electricity, reliably produced by chemical reactions in batteries since Volta’s first one in 1800. In 1872 the British physicist James Clerk Maxwell summarized its properties as we still know them: Current (in watts) equals Power (in volts) divided by Resistance (in ohms). Batteries allowed experiments that identified all the basic elements that we’ve found useful, and powered the long-distance telegraph. In biology all the major species had been described in detail.

Experiments with electricity in vacuums—produced the same way as light bulbs (1879)—were soon to upset our old certainties and lead to the atomic age, but there were no premonitions of this in 1872. The first practical application involved electomagnetic waves that could travel through space (Hertz, 1885), which led to the radio telephone (1896) not long after Bell’s hardwired variety (1876). Another revolutionary discovery took half a century to affect daily life. Back in 1831 British physicist David Faraday had invented the dynamo, which generated electric current by moving a magnet through coiled wire, but a full-sized version was introduced only in 1884--producing modern alternating current.

One mental earthquake had just begun, but seemed so far-fetched that most people didn’t yet pay serious attention to it. British biologist Charles Darwin had demonstrated, by observing related species on isolated islands, that life forms were not fixed as if created, but rather evolved by trial and error over many ages (The Origin of Species, 1859). If you thought about it, that principle should apply to mankind as well, as Darwin had just argued (The Descent of Man, 1871). Of course that would take longer than people thought the earth had existed. A Bishop Ussher had interpreted Biblical geneology to arrive at October 23, 4004 BCE, as the date the world began. Although thinking people might have suspected spurious accuracy, there was little evidence to the contrary until geologist Charles Lyell showed that existing rock formations must have taken millions of years to develop (1830-1833). Put that together with Darwin and you had a major confrontation with the Bible creation story—which Darwin had been so afraid of that he delayed publication for two decades. Newspapers jeered, and ran cartoons of Irishmen (of course) who looked like gorillas, but grown-ups probably never let Susan hear the issue discussed.