"One gets a certain thrill from discovering something others had not known," Orville Wright remarked to Fred C. Kelly, who was then working on a biography of the Wright brothers. After Orville's death, the family gave Mr. Kelly exclusive access to the Wright letters now in the Library of Congress. "I think," he writes us, "that they are the most important unpublished letters now available anywhere in the world. They deal with a subject that has brought a greater effect on the world than anything since the discovery of America." The Atlantic will serialize them in three installments, of which this is the first. Kelly is also the author of Miracle at Kitty Hawk: The Letters of Wilbur and Orville Wright.