It's time to get medieval on physics with the Catapults & Crossbows kit from Thames & Kosmos! Build ten sleek and updated models of catapults and crossbows. These classic siege weapons from the middle ages also happen to be great tools for teaching physics, including lessons in force, energy, motion, and projectiles. Includes a 32-page, full-color manual with illustrated step-by-step instructions. Recommended for ages 8 years and older.