IT has never been easier to read up on a favorite topic, whether it’s an obscure philosophy, a tiny insect or an overexposed pop star. Just don’t count on being able to thumb through the printed pages of an encyclopedia to do it. A series of announcements from publishers across the globe in the last few weeks suggests that the long migration to the Internet has picked up pace, and that ahead of other books, magazines and even newspapers, the classic multivolume encyclopedia is well on its way to becoming the first casualty in the end of print...