well, I've never found a photo of a human cannonball mounted to a truck until now, so I simply am compelled to post this... a mobile human cannon ball exhibition truck! 1934

On April 10, 1877, a 14-year-old girl called “Zazel” was the very first human cannonball, she was launched from a spring-loaded tube in London. She started a pretty fun exhibition tradition for circuses

The the 1920’s, the ingenious Ildebrando Zacchini invented a compressed air cannon, which increased the flight range, and the cannon blast noise was a sound effect produced by igniting half a cup of gunpowder as his son was being shot from the cannon. 

https://art-sheep.com/the-art-of-shooting-people/
https://www.jalopyjournal.com/forum/threads/vintage-shots-from-days-gone-by-part-2.1154030/page-775#post-13794707

https://www.flickr.com/photos/sdasmarchives/albums/72177720295447595/page7