To see it in action, click on the Environmental Editor and set
your parameters.

Click Save Changes

Click on the Environment tab below to view what you will be burning

From here, click the Step button at the top to see the path of fire. This
button can be pushed multiple times to watch the progression of the fire.

Note the first: you may have to zoom out to see the full environment

Note the second: This applet requires JDK 5.0 Update 6 in order to run.
This can be downloaded at http://java.sun.com/j2se/1.5.0/download.jsp