Homemade Rocket Stove

I have seen articles about Rocket Stoves in various magazines and I have wanted to build one.  I finally got around to building one. It boiled water in 15 minutes and we tried it out to cook burgers.  We used a cast iron pan and the burgers cooked up nicely.  You need very little wood to keep the fire going.  It makes a nice backyard cooker or one we can take camping.  It is also a good emergency stove since anyone could probably gather enough wood around the yard in a pinch.