I am trying to recall a story I read a long while ago (from the Grimm Brothers), about "eternity". It goes something like this:
Far, far away, there is a mountain made of pure diamond. It is a league (1) long, a league wide, and a league high.
Once every hundred years, a little bird comes to this mountain, and whets his beak.
When the entire mountain is thus worn off, the first second of eternity has passed.(This is the story as I rememberd it. Researching, I found that this is actually part of a somewhat longer story, which you can find at
http://fanzone50.com/Tales/Eternity.html. Another short story from the Grimm Brothers, which I found quite impressive, is "The messengers of Death", which you can find at
http://www.ucs.mun.ca/~wbarker/fairies/grimm/177.html).
(1) A league is the distance a person can walk in an hour.
Difference in opinions hath cost many millions of lives: for instance, whether flesh be bread, or bread be flesh; whether whistling be a vice or a virtue; whether it be better to kiss a post, or throw it into the fire... (from Gulliver's Travels)