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Turns out they were firing pyrotechnics with a trebuchet at nearby Warwick Castle and accidentally blew a giant smoke ring.

How do I sign up for that gig? Sounds like something straight out of Mythbusters (which is, of course, my dream job).

Can’t think of any drive-by inanities for this one…

Sigh Smoke rings bring back memories of my misspent college years. Smoke rings are the reason I started smoking pipeweed, er, ahem, tobacco…. I was taken by the image of Gandalf blowing elaborate smoke rings and set out to learn to do the same. I got pretty good at it too.

I could regularly blow a ring inside a ring, but the hat-trick remained elusive, appearing only when there were no witnesses. “Old Golds” were my cigarettes of choice, and were made of the finest floor sweeping ever to leave Raleigh North Carolina.

Smoke ring from a trebuchet? That just doesn’t make sense. A smoke ring is simply a vortex ring with smoke in it so it is visible. Vortex rings are fairly simple to generate but they do have some specific requirements. Those are easily met with a large coffee can with a hole about 3/4 to 1 inch in the metal bottom and the plastic lid snapped on the top. Tap on the plastic and a vortex ring comes out the other end. With practice you can blow out candles across the room with one.

A trebuchet is a long pivoted beam with unequal arms with a heavy weight on the short arm and a basket or sling for the payload on the other arm. There’s no air chamber or for that matter any semblance at all of the needs for vortex generation.

So – I call BULLSHIT on, at the very least, the name those pyrotechnicians are using for their wonderful device, one of which I’d simply love to have.

Once saw a smokestack at a sawmill puffing out smoke ring after smoke ring for about ten minutes.

Regardless. Still cool.

Uncle Al,

I was at Warwick Castle last summer with my family and saw the trebuchet in action. As part of the show they launch a “fiery missile”, which essentially is a big boulder coated in tar-like stuff that ‘burns real good’. The action of the trebuchet throwing a round object could possibly create the vortex you describe which is then made visible by the thick black smoke from the flammable coating.

Tom – Thanks for that. I’m beginning to see how that might work!