This Planetarium Tellurium took 10 years to make due to the complex and precise movement that is needed. By using a going train and winding barrel this unit is the most accurate clockwork version of its kind. For easier viewing the earth has been made larger. Normally it would be 109 times smaller then the sun, but this would make it difficult to see what is happening. To get the planetarium-tellurium to work a lever system is used which can keep the device going for 15 days.
For a more precise explanation check out Horomundi.