A pendulum clock running only on the potential energy of the weights. There aren't any motors in this clock.
It runs about a half second late every minute..
The black parts are the main clock construction.
The red parts are the weights.
The green parts are used to wind up the clock.
How to wind up the clock:
1. Press and hold the LEFT arrow key.
2. Then press and hold the UP arrow key. The weight will begin to rise.
3. When the weight is fully up, release the LEFT arrow key.
4. Wait about a second and just then release the UP arrow key.