Machu Pichu: The Wonders of Man Series, by John Hemming.New York: Newsweek Books (dist. by W. W. Norton & Co.). 172 pp. $16.95.

The year is 1910, and holding forth in the convivial atmosphere of a Yale class reunion is young Hiram Bingham. So compelling is the personality of this handsome, wealthy mountaineer-explorer, so bewitching his tale of a fabulous lost city of the Incas that that his fellow alumni join together to persuade the university to finance an expedition in search of the site.Cut to Cuzco, one year later as Bingham and his company, two weeks out, encounter a local peasant who leads them to a granite cliff, from which Bingham gazes on what, forgotten and undisturbed, are to become the most famous ruins in South America, the most breathtaking, perhaps, in all the world, the lost Inca citadel, Machu Picchu.Sound like a sequel to ''Raiders of the Lost Ark''? Maybe, but this story is true, and Bingham's adventure is merely the first chapter in this admirable book, which contains a wealth of tantalizing information concerning the expedition, Inca civilization, and Peruvian geography and culture.