Then I'll put the hat on your head, screw the pump into the small of your back and fix the other machinery down your legs." "I'll see you hanged first." "Well, then, I'll put it on myself and illustrate the theory for you.
You see the rod here in my trousers?
This is the air-pump here, just above my suspender buttons.

The hat now contains about six atmospheres.

Now I am ready to move.

See?
You observe how it works?
The only noise you hear is a slight click of the valve in the pump.

A couple more turns, and you put your hand on my shirt-collar and feel how near zero it is.