NMFREE, I am very disappointed in you.
It should be a rule that you cannot post something like that without more details on how it is done.
It reminds me of the famous line, "Hey, hold my beer and watch this!"
Gunpowder?
Gasoline. I used to do that to clear wood piles on my property, but without the leaves. Dump a lot of gas on the pile with a long trail of gas to light point. I would do this while carrying a stake. I would plant the stake at the end of the gas line. The stake tells me where to light it. I would light at a higher elevation.
If you light a bunch of gas it has boom-like ignition.
It's gasoline, this happened to me before by accident. I poured gasoline on a large pile of leaves and was trying to light it with strike anywhere matches. I didn't get it started with the few that I had in hand and had to go to the garage to get more. In the very short time that I was away from the pile the liquid had begun to evaporate into a gaseous state. When I came back and threw a lit match on the pile the vapor exploded into a column of fire several feet high, sending burning leaves everywhere. It scared the crap out of me because I wasn't expecting it but now I do this every year when cleaning up the yard. Gotta love science.
This is why I used the stake and have the wand lighter on me. Its important to be at a higher elevation and be an arms length from the ignition point. Most importantly be in the right spot so as to not light your own a$$ on fire.
Gasoline can be deadly if you don't know what you are doing.
Truth.