Once the moon gets to be full somebody - some man or other - goes up every day and slices bits of one side until there isn't any more,and then after a bit a new one grows. Men do that with all sorts of things, actually - rose bushes for instance.... The man who slices the bits off brings them down here and then they're used for making those lights on the cars. Clever isn't it... They only last about one night, I should think, because you hardly ever see them shining by day.

Richard Adams