This is of a type known as a transparent orrery, but is in reality more nearly allied to slides made for projection. It consists of a mahogany case with a glazed, hinged front. Inside, a painted scroll is mounted on rollers, which can be wound round to display different sections. Against a painted black background are scenes demonstrating the four seasons, the phases of the moon, the equinox, eclipses on the moon and sun, the solar system, and the constellation of Hercules. When in use, the back is removed and a lamp is placed behind.

A plaque on the back is inscribed "Hudson and Son, Opticians, Greenwich".