when the containers were the screw top to metal containers , we used them to make salt peter and other ingredients , combined made perfect launching bombs for rocks and stones.
now I am going back to my youth when this was a popular thing to do .. put a tube into the ground, make the concoction in the photo can, put a wick on it and place at bottom of the tube with wick out to lite, put rocks on top to photo can, light wick , send rocks over houses to land on cars driving down steet... who says the kids today are assholes .. I think we invented that.