Assertion: reed | /r/HasAspect | exhausted space
Facets:
Source sentences:
text: The closing of any register is made to open a small valve within it, called a pneumatic stop, by which communication with the exhausted chamber is at once made both above and below the reeds, and the latter are then within the exhausted chamber; but upon opening the register, this valve closes, and thus other communication is cut off above, and the reeds have the exhausted space now only within, the atmosphere acting from without.