Unicorns' horns, mermaids' skeletons, stuffed and preserved animals and plants, precious metals, clocks, scientific instruments, celestial globes--all knowledge, the whole cosmos, arranged on shelves in a single room. Such were the cabinets of curiosities of the seventeenth century, the last period of history when man could aspire to know everything. The collectors were archdukes and kings--the Emperor Rudolf II was the prince of all collectors--rich...