Ruler is the main measuring tool in ancient and modern times. The ancient ruler has many uses, one of which means to measure everything in the world and master everything in the world. That is, when the ruler is used as a weapon, there is a kind of ruler weapon named measuring ruler. Today's ruler represents the unit of length and the measuring tool. It is basically the same as in ancient times, but it lacks other meanings, such as weapons and evil spirits.
In addition to measuring tools and weapons, the ruler is also useful in the number of techniques. The Qingtian ruler in history also means to ward off evil spirits in woodworking tools. There are standards for the specific specifications of ancient buildings and furniture, but generally speaking, the dimensions of buildings are singular, and the dimensions of woodworking furniture are in the style of how many inches and a half. If you are interested, you can measure the ancient furniture or beam.