Alexander the Great in a glass submarine on a French miniature of the 15th century

Medieval legends attribute to Alexander the Great a passion for exploring the natural world, notably in a glass submarine in which he sat with a cockerel, a cat and a dog. In this miniature from a fifteenth-century French book, "The True History of the Good King", an unfaithful wife tries to kill Alexander by cutting the rope that attaches the submarine, with him inside, to the ship. The text says that his animal companions were chosen for good reason: the cockerel was needed to tell the time, the cat, strange as it sounds, to filter the air, and the dog, more surprising still, as a living anchor, upon whose death the vessel could rise to the surface