Retired teacher Shi Yueding and his hand-drawn 'engineering diagrams'

In the history museum of School of Mechanical Engineering, Zhejiang University, there’s a remarkable teaching poster of an engine from 1987. Entirely hand-drawn, this intricate piece was created by Shi Yueding, a retired teacher from the same department. To help his students better understand the material, Mr. Shi came up with the idea of hand-drawn teaching diagrams.