An Erisdar was a kind of lantern, invented by the elf of the same name, which burnt without fire through magic. These multicolored lanterns were a common sight in cities of the elves and the dwarves. Erisdar were very dangerous if broken, as Eragon discovered in Brisingr when Eragon was almost assassinated under Tronjheim by several black garberd dwarves. One of the assassins accidently struck the lantern and it exploded, killing the black garbed dwarf as it did so. However the explosion only burned Eragon's back and deafened him, both of which he healed with magic.