After reading Romance of the Three Kingdoms, I was surprised to see a lot of references to 砲響 (the sound of cannonade). Here's a few examples:
Obviously there was no gunpowder or cannons back then (the story was set in the 3rd century AD, and gunpowder was thought to have been invented in the 9th century AD), and the character 砲 suggests that it's a catapult instead. But the passages and wording (一聲砲響) suggests that it makes a single loud sound heard across the battlefield. Were catapults really that loud? Why would it be a single sound, and not a series, i.e. if a commander has multiple catapults and orders a volley? Or is it something other than a catapult?