Books: What Mark Said About Sam

THE AUTOBIOGRAPHY OF MARK TWAIN (388 pp.)—Edited by Charles Neider—Harper ($6).

"I am not alive. I am dead," wrote Mark Twain. "I wish to keep that fact plainly before the readers. If I were alive I would be writing an autobiography on the normal plan." There was certainly nothing normal and no plan about his autobiography. He began writing it at 42 and believed that it "would live a couple of thousand years." When he died at 74, in 1910, he left about 500,000 words of notes, scraps, reminiscence and recrimination.

Since then three...