Cheiroballistra
The cheiroballistra (Greek: χειροβαλλίστρα) was a small, two-armed, torsion-powered, metal-framed catapult known from an anonymous Greek treatise titled "Heron's Construction and Dimensions of the Cheiroballistra" (Ἥρωνος χειροβαλλίστρας κατασκευὴ καὶ συμμετρία). The name breaks into two parts: cheiro- (χειρο), a combining form of the word "hand," and ballistra (βαλλίστρα), from the Greek ballein ("to throw").