I just listened to an interview with Edmund Morris, British author of Colonel Roosevelt, the last of a biographical trilogy.
Theodore Roosevelt, best known for being a President, Rough Rider, hunter, explorer, naturalist, and for giving his name to Teddy Bears, was an extraordinary reader.
Morris claims that Roosevelt read on average one book a day. He read with phenomenal speed -- about 3 pages per minute -- and retention: "He was photographic in his memory." He read English, of course, but also German, French and Italian.
How did he manage it? In addition to having servants to relieve him of mundane chores, Roosevelt believed that no waking minute should be wasted. If his carriage was 3-4 minutes away, there was an opportunity to read half a chapter. He sounds like a man who hardly ever stared vacantly into space. "Well, yes, he was exceedingly erudite," Morris drawled.
At the end of the interview, Morris said that he was never "in love" with Roosevelt; he feels it's dangerous for a biographer to be in love with his subject. He conceded, though, that it's unlikely he'll ever again write a biography of anyone of Roosevelt's stature. I certainly don't know any readers of his caliber.