Cradled in the lap of the Andes, Santiago harbors 4.5 million, more than a third of all Chileans. A veil ofsmog is common; the Andes form a wall that traps pollu tion. In an outlying town bikers get ready to roll in a procession highlighting the post-Easter holiday known as Quasimodo. someone of the regime's confidence must win the coming referendum or within 12 months hold free elections and step down. But some Chileans fear that a resounding "no" vote might drive a desperate Pinochet to kick over the game board with savage repression rather than retire. Chile faces this crisis behind the barriers of the world's driest desert, deepest ocean, cold est ice fields, and longest mountain chain, the Andes. Their nation's extraordinary geogra phy accustoms Chileans to view themselves as remote islanders, but it has cost them psycho logical contortions to endure isolation these 15 years in a political landscape whose excesses depress, repel, and intimidate. Yet they have learned a secret of survival: "Maybe we're just wise enough to know how to have fun once in a while," main tains a journalist friend, herself a past tar get of threats and bullets. "Some think they shouldn't, that Chile is too depressing ever to be happy in. They're wrong, for even if Pino chet died tomorrow, no one could give you back the years you stopped laughing." There are real grounds for the self-appraisal: "Somos chilenos, somos diferentes--We're Chileans, we're different." FEW SINCE Ferdinand Magellan have come with such dramatic effect upon the lon gest narrow country on the planet-only 177 kilometers (110 miles) wide on average and strung like a ribbon down South America's lower west coast between the Andes and the Pacific. At other latitudes Chile, with the Ant arctic territory it includes within its borders, would stretch from the North Pole to Jamaica. Its remotest city of Punta Arenas clings to land's end some 2,000 kilometers south of San tiago, yet lies only a third of the way from the capital to the South Pole, the limit of a Chilean claim to 1.25 million square kilometers (483,000 square miles) of the coldest continent. And 3,800 kilometers west over the Pacific brood the giant stone heads of Chile's most dis tant oceanic speck, Easter Island. None of this appeared on Magellan's charts in 1520, when the Portuguese navigator sail ing for the Spanish crown gambled that a strait wending V-shaped between the toe of South America and a labyrinth of islands might prove a long-sought sea track from Atlantic to Pacific. Magellan took on water from a mountain ous island half as large as Portugal, which he christened Tierra del Fuego, "land of fire," for the Indian watch fires he saw. Its clouds, flame-lit like auroras, fell away behind as Ma gellan swung his three naos northwest, skirt ing ever more islands, channels, glaciers, and twisting peninsulas. They splinter Chile's southern third into a wilderness slowly open ing as geostrategist Pinochet, his wary eye on more populous Argentina, forces forward a dirt-and-gravel highway in a Chilean coloni zation thrust toward Punta Arenas. National Geographic,July 1988