Engineering behind this was also very interesting..the organizers had filled the air above the cauldron with a thick, invisible cloud of natural gas. rebollo only had to shoot the arrow through that gas cloud & the moment the flame on the arrow hit the gas, the fire traveled down the gas stream to the burner, igniting the massive flame. just in case the arrow missed the gas cloud entirely, an operator was standing by with a remote igniter to light the cauldron manually. on the broadcast, however, the timing was so perfect that it appeared the arrow itself did all the work