George MacDonald,
The Princess and the Goblin — Chapter 8
(1872)
“ He now knew at least one of the reasons for the constant sound of the goblin hammers and pickaxes at night. They were making new houses for themselves, to which they might retreat when the miners should threaten to break into their dwellings. But he had learned two things of far greater importance. The first was, that some grievous calamity was preparing, and almost ready to fall upon the heads of the miners; the second was - the one weak point of a goblin's body; he had not known that their feet were so tender as he had no reason to suspect. ”
