Nasr al-Ghuráb had told them that in the sack of Constantinople the Ottomans had discovered, in a dungeon, a device that the Byzantines had once used to put out the eyes of noble prisoners. There was none of poking or gouging. Rather, it was a great hemispherical bowl, wrought of copper, with a sort of vise in its center. The bowl would be heated first until it was glowing, and then the prisoner’s head—masked, except for the eyes—would be clamped into the vise. The apparatus was so laid out that the pupils of the victims’ eyes were positioned at the center of the hemisphere. When the lids were pulled up, the eyes could see nothing but a featureless heaven of red wrath that ruined even as it dazzled. The sensitive parts of the eyes were incinerated in a few moments, and the victim rendered perfectly blind without the eyes themselves ever having been touched by anything save that awful last glimpse.