Now goblins are cruel, wicked, and bad-hearted. They make no beautiful things, but they make many clever ones. They can tunnel and mine as well as any but the most skilled dwarves, when they take the trouble, though they are usually untidy and dirty. Hammers, axes, swords, daggers, pickaxes, tongs, and also instruments of torture, they make very well, or get other people to make to their design, prisoners and slaves that have to work till they die for want of air and light. It is not unlikely that they invented some of the machines that have since troubled the world, especially the ingenious devices for killing large numbers of people at once, for wheels and engines and explosions always delighted them, and also not working with their own hands more than they could help; but in those days and those wild parts they had not advanced (as it is called) so far. (4.22)

They had thought of coming to the secret door in the Lonely Mountain, perhaps that very next last moon of Autumn – "and perhaps it will be Durin's Day" they had said. Only Gandalf had shaken his head and said nothing. Dwarves had not passed that way for many years, but Gandalf had, and he knew how evil and danger had grown and thriven in the Wild, since the dragons had driven men from the lands and the goblins had spread in secret after the battle of the Mines of Moria. Even the good plans of wise wizards like Gandalf and of good friends like Elrond go astray sometimes when you are off on dangerous adventures over the Edge of the Wild; and Gandalf was a wise enough wizard to know it. (4.3)