41 x 29 cm
This instrument is composed of a light bulb inside a red globe which represents the Sun, and two globes which represent the Earth and Moon. The three globes are linked by mechanical devices. The Earth rotates around the Sun along the ecliptic. The Moon orbits around the Earth in the moon's path.
This instrument is a demonstration model and a teaching aid to show the relative movement of the Sun, the Moon and the Earth, the formation of day and night, the change of the Moon, the eclipse of the Sun, and the cause of the four seasons.
- Research Project on Village Schools in Hong Kong