As a child, I used to love watching Shirley Temple's movies and I was drawn to reading her autobiography, Child Star. This was one of the best Hollywood autobiographies I have ever read because of the way Shirley gave a complete overview of her life.
Definition of engineer's brake valve. : a valve in the cab of a locomotive for operating the air brake.
The word is derived from the Latin valva, the moving part of a door, in turn from volvere, to turn, roll. The simplest, and very ancient, valve is simply a freely hinged flap which drops to obstruct fluid (gas or liquid) flow in one direction, but is pushed open by flow in the opposite direction. This is called a check valve, as it prevents or checks the flow in one direction.