You can still do that easily today: https://en.wikipedia.org/wiki/Rocket_candy https://en.wikipedia.org/wiki/Rocket_candy I have seen potassium nitrate stump r

You can still do that easily today: https://en.wikipedia.org/wiki/Rocket_candy https://en.wikipedia.org/wiki/Rocket_candy I have seen potassium nitrate stump remover on the shelves at my local Fred Meyer (Kroger). If you can't find find it on shelves it's easy to order: https://www.walmart.com/ip/Potassium-Nitrate-Powder-99-8-Pure-5-Lbs/919446004 https://www.walmart.com/ip/Potassium-Nitrate-Powder-99-8-Pur... The vast majority of fireworks and rockets I made as a kid used potassium nitrate as an oxidizer. 5 pounds will provide many hours of entertainment and education.