A bare list of the names of fairies and subhuman beings is inspiring. In the Norse countries there are dwarfs, known also as trolls, kobalds, goblins, brownies, pucks, or elle-folk. It is said that 'they are less powerful than gods, but far more intelligent than men; that their knowledge is boundless and extends even to the future. They can transport themselves with celerity from one place to another, and love to hide behind rocks and repeat the last words of every conversation they overhear. Echoes are known as dwarfs' talk. A Tarnkappe each one owns, a tiny red cap which makes the wearer invisible. Dwarfs are ruled by a king spoken of in various northern countries as Andvari, Alberich, Elbegast, Gondemar, Laurin, or Oberon. He dwells in a magnificent subterranean palace and owns a magic ring, an invisible sword, and a belt of strength. His subjects often fashion marvelous weapons and girdles. In general, dwarfs are kindly and helpful: sometimes they knead bread, grind flour, brew beer, and perform countless other household tasks; sometimes they harvest and thresh grain for the farmers. If ill-treated or turned to ridicule, these little creatures forsake the house never to come back to it again. Sometimes they take vengeance by means of changelings. Changelings are the weazened and puny offspring of the dwarfs which they substitute for unbaptized children that they steal from people who have offended them. The dwarfs, envious of the taller stature of the human race, desire to improve their own, and so consider it good morals thus to make their enemies their benefactors.' Fairies, elves, and ariels include all the small creatures who are fair, good, and useful. They have their dwelling-place, it is said, 'in the airy realm of Alf-heim (home of the light-elves), situated between heaven and earth, whence they can flit downwards whenever they please, to attend to the plants and flowers, sport with the birds and butterflies, or dance in the silvery moonlight on the green.' They have golden hair, sweet musical voices, and magic harps. These gentle aerial beings, scholars say, were introduced into Europe by the Crusaders and the Moors of Spain. Before that time the creatures of the North had been cold and ungenial, like their heath-clad mountains, chilly lakes, and piny solitudes; but after the advent of the Peri of the East, who live in the sun or the rainbow and subsist on the odor of flowers, the Northern elves took on more winning attributes and finally became beneficent and beautiful.