Built a bunch of these - both combustion and “compressed air” based as a teenager, with varying results. I had been inspired by a “science demonstration” at a

Built a bunch of these - both combustion and “compressed air” based as a teenager, with varying results. I had been inspired by a “science demonstration” at a science fair where “Doctor Bunhead” (of “Brainiac” TV fame) shot one through a tennis racquet to make “instant chips”.