I received a copy of Mini Weapons of Mass Destruction: Build Implements of Spitball Warfare by John Austin for review a couple of weeks ago. My boys loved it! This book shows them how to make miniature catapults, bows, and other projectile machines out of common office supplies. This book would make a great basis for an open house or a just for a fun meeting.
Here are some of the things I liked about this book:
Instructions: The instructions are clear and easy to follow. When this book arrived, ZM (who is currently 10 years old) immediately opened it up and made a tiny bow and arrow from a rubber band and some pens. He did this without any help from me whatsoever and it only took him a few minutes. This was followed right away with him making a coin shooter from a balloon and a toilet paper tube. Both machines worked great and he was really proud that he made them all by himself.
Materials: The materials for the most part are things you already have lying around your house. Most are office supplies like pens, pencils, rulers, rubber bands, and clips. You can make most of the things in the book without hunting around for some special part.
Variety: The machines in the book go well beyond the typical spoon catapult. Have you ever made a miniature trebuchet? You can teach the engineering concepts involved in making these machines on a small scale. There chapters cover small launchers, bows and slingshots, darts, catapults, combustion shooters, and minibombs and claymore mines. There are multiple designs in each chapters. Some designs include optional add-ons, like adding a laser pointer for sighting. Plus the final chapter tells you how to make tiny targets, like castles and aliens.
Safety: The book does discuss safety and recommends safety glasses for some of the machines. Most of the implements are not that hazardous, but I gave my sons a blanket “no shooting this stuff at each other” rule just in case. If you are doing these in a Scout meeting setting, you would want to consider safety when choosing which designs to implement.
Fun: The tone of the book is lighthearted. The fact that my copy is already dogeared after two weeks is a testament to how much fun my boys are having with it. And whether they realize it or not, they are experimenting with engineering concepts at the same time.
So I recommend this book for ages 10 (or so) and up. The adults will also have fun with this one. My only caution is to make sure younger children are capable of understanding the safety concepts.