Ishmael compares the heads of the sperm and right whales. He sees the sperm whale’s forehead as an extremely efficient battering ram while the massive tun of oil in the sperm whale’s head reminds him of the Heidelberg Castle wine cask, which has a capacity of 49,000 gallons. Tashtego falls into the whale’s head and is rescued by Queequeg. The sperm whale’s brain is relatively small, only a “nut.”
