1. The very tip of a swallow’s wing as it cuts the air.
  2. The sword that splits the plum, pit and all.

These are said to resemble Royalty. It is not curved in the slightest. Turn the wheel on its side and you will see its shape. Cut the wheel in half and you will see its shape between the two halves. This is its purest expression, in the non-space. Observe how it extends forever, and look how it glitters!