Toby had said before they left the Sanctuary. Rhyn unscrewed the lid of the full bottle, recognizing the scent of Katie's blood at once. It made his body roar to life, and he realized just how hungry he was. He'd foregone food after her death, hoping to starve himself.
8 the ball bearings are shown unscrewed from the body of the log, with eye, cap and spindle.
It in fact ensures that the wing, and the curtain or fringe of the wing which the primary and secondary feathers form, shall be screwed into and down upon the wind in extension, and unscrewed or withdrawn from the wind during flexion.