What Happened and Why

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.

What a Beaver Dam Does

A beaver does not build a dam for shelter. It builds one to make a pond, and it lives in a lodge in the pond. The dam raises the water so the lodge entrance stays underwater. A predator that cannot swim cannot get in. But the pond does far more than protect one family. Behind a dam, water slows, and slow water drops the silt it carries. Over years this builds rich wet ground. That ground holds water in a drought and holds it back in a flood. It supports plants, insects, amphibians and birds that were not there before. Where beavers have been reintroduced, the number of species in a valley typically rises within five years.