3, wolf smoke. Wolf smoke is a signal of fireworks lit at the beacon tower when the ancient border guards found the enemy. The most familiar allusion is Shangzhou Zhou Youwang, who lit the beacon tower and made the guests smile. He lit this bonfire to convey the enemy's invasion and needed the surrounding governors to come to the rescue. This is also often used in wartime, when there is an invasion from other places or when people call for help.
4. letters. In ancient times, rich people also had special messengers. They will get their cars and horses ready, and then they will send the letter where they need it. Letters from people who have no money are mainly sent by fellow villagers and friends who are on business trips or come from afar. Of course, this mode of transmission is not as fast as that of the imperial court.
5. Word of mouth. In ancient times, there were some common ways to transmit information, such as rumors, storytelling or poetry, which were all transmitted in people's chats.