In 1962 the museum was expanded as a regularprism designed internally with mezzanines that occupied the space that Kronfuss had imagined as the central courtyard of the museum.
The shape of block stones shall be close to straight prism or regular quad or polygons.
块石形状应接近直棱柱体，或有规则的四边形或多边形。
3
Then by taking the regular square prism as an example, the machining error is analyzed, and the relationship among the length of the lathe tool, the work dimension and the tolerance is obtained.