Students in Alex Siragy's Engineering and Design course designed and built large trebuchets this spring. Throughout the design and build process, students (all juniors but one) tested their devices outside. They launched balls of all sizes, made adjustments to pouch/sling, payload and counterweights to improve aim and accuracy and increase distance of each launch. It was an amazing process to watch. Finally, during Spring Day activities, the class held a trebuchet launch demonstration and competition for the school. Flat wooden targets were put up at one end of the outdoor basketball court and the devices were set up at the other end. Teams (there were three devices built by teams of students) practiced launching water balloons to make adjustments, then began launching paint-filled balloons at their wooden targets. To the audience's (and team members') delight, every trebuchet functioned well (a first for this class over the years to have 100% success) and some balloons hit the targets with very satisfying splats of color. Check out the photos of this very hands-on Engineering project.