Caption:
The corvus was a Roman naval boarding device used in sea battles against Carthage during the First Punic War. Polybius describes this device as a bridge 4 ft wide and 36 ft long, with a small parapet on both sides. A pole and a system of pulleys allowed the bridge to be raised and lowered. There was a heavy spike shaped like a bird's beak on the underside of the device, which was designed to pierce and anchor into an enemy ship's deck. This allowed a firm grip between the vessels and a route for the Roman legionaries to cross onto the enemy ship and capture it. Illustration from Ship & Ways of Other Days by Edward Keble Chatterton, 1913 (cropped and cleaned).