How This Text Is Built

Why Clocks Agree

Until the 1840s, every British town kept its own time, set by the sun. Noon in Bristol was about ten minutes after noon in London. That was no problem while the fastest thing on the road was a horse. The railways changed it. A timetable cannot work if every station measures noon differently, and trains sharing a track need to agree about when. So the railway companies imposed London time on their whole network. People called it railway time. Some towns kept two minute hands on the town clock for years, one local and one railway. In 1880 Parliament made a single time legal across the country. The sun had been overruled by the timetable.

The Accidental Photograph

In 1895 Wilhelm Röntgen was working with a covered tube in a darkened room when he noticed a screen across the laboratory glowing. Something was passing through the cover and crossing the room. He did not know what it was, so he called it X — the unknown. He spent seven weeks alone in the laboratory testing it. He put wood, rubber and metal in the way. Metal stopped it; the rest did not. Then he asked his wife to put her hand between the tube and a photographic plate. The picture showed the bones of her hand and her wedding ring. Within a year, X-rays were being used in hospitals. Röntgen refused to patent them.