Is your ten-year-old son interested in the Middle Ages? Or are you a ten-year-old boy at heart? Whether you're a history buff, or you just like firing stuff, you'll love these make-your-own catapults.

Storm the Castle, a medieval-theme website, provides instructions for making catapults in various sizes: the backyard two-foot Ogre, the tabletop ten-inch Troll, and the Teeny-tiny, made of popsicle sticks.

If you're interested, Storm the Castle provides tutorials and/or sells kits, so that anyone who can read can put one together. All three catapults can shoot with considerable force, so you're reminded to take appropriate safety precautions:

• don't fire anything sharp or too heavy
• don't fire in an enclosed space
• always wear safety goggles.

If you're letting a child build this, you might consider only letting them play with it under adult supervision, depending on his/her age and general level of common sense (or lack thereof)!