 In "The Hobbit", it is revealed that Gandalf gave the Old Took a pair of magic diamond studs that fastened themselves and never came undone until ordered.The functions of "palantíri" are similar to modern videophones (although the sound is not transmitted, and instead thoughts are "transferred between wills") and powerful telescopes; but "palantíri" do not have any mechanical workings and are clearly magical, resembling specula, or divining spheres used by soothsayers.Moon-letters were discovered by Elrond on "Thror's map" of the Lonely Mountain, which revealed the method of opening the secret entrance