Celestial half globe for teaching purposes - has rigid shell with grooves on inside which is covered by plastic layers on inside and outside

摘要

The grooves on the inside of the rigid hemispherical shell are concentric with the edge of the shell and there is a small depression at the pole position. The plastics covering layer is in one piece, curving over the edge of the hemispherical shell. Breather valves allow the air to exhausted from inside and outside so that the plastics covering clings to the shell. The plastics covering corresponds to the entire celestial globe, and the portion visible on the outside corresponds to the portion of the sky visible above the horizon. Guide pegs may run in the grooves and plastic strips may be used to illustrate the movements of the planets.