orrery

planetarium consisting of an apparatus that illustrates the relative positions and motions of bodies in the solar system by rotation and revolution of balls moved by wheelwork; sometimes incorporated in a clock

आकाश का यंत्रसमूह नक्षत्र-भवन की तुलना में बहुत स्पष्ट है|

the machinery of the heavens is much simpler than that of an orrery.