What was "the brazen bull"?

The brazen bull, also known as the bronze bull, Sicilian bull, or bull of Phalaris, was a torture and execution device designed in ancient Greece. According to Diodorus Siculus, recounting the story in Bibliotheca historica, Perilaus (or Perillus) of Athens invented and proposed it to Phalaris, the tyrant of Akragas, Sicily, as a new means of executing criminals.

The bull was said to be hollow and made entirely out of bronze with a door on one side. According to legends, the brazen bull was designed in the form and size of an actual bull and had an acoustic apparatus that converted screams into the sound of a bull. The condemned were locked inside the device, and a fire was set under it, heating the metal until the person inside was roasted to death.

The Romans have been claimed to have used this torture device to kill some Christians, notably Saint Eustace, who, according to Christian tradition, was roasted in a brazen bull with his wife and children by Emperor Hadrian. The same happened to Saint Antipas, Bishop of Pergamon during the persecutions of Emperor Domitian and the first martyr in Asia Minor, who was roasted to death in a brazen bull in AD 92.