During the Spring and Autumn Period and the Warring States Period, oil lamps for lighting began to appear. Beans were the tools for lighting at that time, which were made according to the shape of the food container-beans at that time. At that time, people used soybean fat as fuel, put soybean fat in a small pottery bowl, put a wick on it and lit a lamp. The Qin dynasty should also use lamps from the Spring and Autumn Period and the Warring States Period.

I suggest watching the second episode of Qin Xun Ji in 7 minutes and the seventh episode of 19 minutes. Because it is a TV series, the truth is unknown, so I won't take a screenshot here. The pictures are for reference only.