Who thought of building a catapult that could sling a cow a couple of kilometres over a castle wall? What made Leonardo design a parachute? Who fired the first cannon ball and how can a lemon power a digital clock? You can find the answers here, in this title of the Crafty Inventions series, and then model your own inventions -- from a miniature flush toilet to a cracking pop-gun. Table of Contents: Catapult Torque Twister First parachute Air resistance Spectacles Lens refraction Water Closet Gravity and weight Printing Press Screw mechanism Cannon power Explosive gunpowder Watch Spring Energy Microscope Reflected Light Thermometer Moving atoms Battery Creating electricity Glossary and Index Tools and materials