"Fëanor, being come to his full might, was filled a new thought, or it may be that some shadow of foreknowledge came to him of the doom that drew near; and he pondered how the light of the Trees, the glory of the Blessed Realm, might be preserved imperishable. Then he began a long and secret labour, and he summoned all his lore, and his power, and his subtle skill; and at the end of all he made the Silmarils."
January 1, 1970
https://en.wikiquote.org/wiki/Doom