Light in the Dark

I was perusing some of Wordsworth's forgotten poems, most of them quite justly forgotten, when I stumbled across this:

EVEN as a dragon's eye that feels the stress
Of a bedimming sleep, or as a lamp
Suddenly glaring through sepulchral damp,
So burns yon Taper 'mid a black recess
Of mountains, silent, dreary, motionless:
The lake below reflects it not; the sky,
Muffled in clouds, affords no company
To mitigate and cheer its loneliness.

This image of a single candle visible from miles away across a lake set me musing on how dark the world used to be on a moonless night. Especially in northern Europe with its heavy clouds and long winter nights, our ancestors lived much in the darkness. Beeswax candles were expensive, and ordinary folk made do with tallow that gave a dim, uneven, smoky glow, or even tried to work by the weak light of a banked fire. Whale oil lamps were such a huge advance that men sailed off on three-year voyages to the southern ocean, there to risk their lives hunting the sperm whale near to extinction for the precious fluid, one shipful of which made the owner rich. When coal gas lights first appeared in London and Paris they were hailed by poets with raptures about repeating the deeds of Prometheus. Now that we are used to such wonders some people worry about the effects of all this light on our sleep, and the way it pushes us to work around the clock, but for those who grew up in darkness, light was a powerful blessing.