The naturalist Eldridge had spent thirty years cataloguing the migratory routes of Arctic terns, and his published maps were models of precision. Yet in his private journals he confessed a different relationship to the work. "I draw these lines," he wrote, "as if the birds obeyed my geometry, when in truth I am only recording the faint pressure of a will I cannot name." He came to believe that every map was less a description than a wager—a guess dressed in the costume of certainty. The cleaner the line, he noted, the larger the lie it concealed.