As the wheel rotates, the gondolas are kept in the upright position by a simple gearing system.
⇑ Translate the sentence above by Google ⇑
Related: upright
Prev: If the small-brained australopithecines were not toolmakers, what evolutionary advantage did they gain by walking upright?
Next: Walking upright permitted the father to use his hands to gather food and carry it to his mate from a distance.