The ruler for measuring shrimp is called shrimp ruler, or shrimp ruler. The most accurate way to measure the length of shrimp is to mark the shrimp ruler from the forehead sword on the shrimp head to the tail fan of the shrimp, and then measure the length of the shrimp ruler head to the marked position with a ruler, so that the length of shrimp can be accurately known.

Introduction to invention

He invented many woodworking tools used by carpenters. Like a wooden ruler, called Lu Banchi or shrimp ruler.

The invention of these woodworking tools liberated the craftsmen at that time from the original heavy labor, and the labor efficiency was doubled, and the civil technology took on a brand-new look. It contains the original knowledge of physics.

Lu Ban is also an outstanding mechanical inventor. The lock he made, the mechanism is inside, and there is no trace outside. It can only be opened with a matching key.