Another "best of" collection, with a particularly tenuous premise: twelve stories, 1839-1966--representing the "first appearance of an interesting idea" (though even here Asimov quibbles a bit). The famous yarns include Murray Leinster's 1946 tale about home computers, "A Logic Named Joe"; Fitz-James O'Brien's exploration of a microcosmic world in "The Diamond Lens" (another, less well-known O'Brien entry describes an invisible being); Larry Niven's "Neutron Star"; and Asimov's robot-catches-religion story, "Reason"--representing the first account of a solar power satellite. There are disappointing entries from great masters: Poe's "The Conversation of Eiros and Charmion" (a comet strikes Earth) and Wells' "The Land Ironclads" (tanks in battle). But most of the remainder is impressive--from Don Wilcox's "multi-generation starship" to a 1952 Fritz Leiber clone tale to Richard Matheson on overpopulation (compulsory euthanasia for the aged/infirm) and Lester del Rey on animal superiority. (Intelligent dogs take over after humanity destroys itself.) Except for a foolish 1937 pulp piece about antimatter, then: an attention-worthy gathering--even if the arbitrariness of the assemblage irritates.