Vintage table top model called an orrery which is a mechanical model of the sun, earth, and moon, used to represent their relative positions and motions. Circa 1900, this model has a 6" brass ball representing the sun and a 2" ball connected by a wood arm representing the earth. A smaller ball connected to the earth by gear and chain representing the moon. Everything sits on a brass base that is marked with the seasons, months, and astrological names. There is a piece of ladder chain missing that connects the earth and the sun gears. Overall good condition. Measures 24" wide, 14" tall