Eric Watson, Saddleworth, England, 1986

The three 600+ toothed outer planet rings are one of the most striking features of this orrery. This was the only orrery that Watson had fitted a chain for the fusee rather than a bronze wire.

These three wheels mesh with the outer planet rings of Mars, Jupiter and Saturn. These wheels are mounted to the counterclockwise rotating orrery armature which turns once in 365 days, one year. However the outer planets orbit much more slowly. So while the armature is moving counterclockwise at the rate of one revolution per year, each wheel is also moving counterclockwise to slow down  the rate at which the rings are moved. Each are calculated to net out the armature speed to obtain the correct orbital period of each planet.

Close up of the wheelworks before cleaning.

Clese up of same area after cleaning.

The red spot indicates daylight savings time. The dial can be moved one hour forward or back by one hour. When the dial is on standard time the hole is clear.

Center armature module having the Sunrise/Sunset cam work and center drive gears, pre restoration.

Restored center armature section mounted to clockwork module.