There is a scene in the movie Ben Hur in which two fleets of ships engage in battle. At one point, deck hands are loading catapults with flaming pitch and an officer shouts out: "READY! AIM! FIRE!" I've always assumed that the phrase related to the use of guns and rifles, so hearing it used in another context intrigued me. I've not been able to find any internet references to the origin of the phrase and was wondering if anyone here might be able the shed some light on the subject.