He had closed the outer panel; the air-pressure in the lock was rising.
We are now getting the air-pressure through the pipe in both ends of the tube alike, and do not move the pellet either way.
Their only purpose was to get the piston lifted, and air-pressure did all the actual work.
This not only guided the flight of the machine, but counterbalanced the changes of the centre of air-pressure.
The carburetor flushes his blood with oxygen, the decompression tank adjusts him to the lack of air-pressure.
If the air-pressure within the ship were released; if even a crack were opened!
Then the fire was removed and, as the cylinder cooled, the steam condensed, and the piston was forced down by air-pressure.
The air-pressure forces piston 12 downwards and closes steam-valve 14, thus cutting off the supply of steam to the pump.
This is because the air-pressure is less on the mountain top than in the valley.
Its function is probably to keep the air-pressure equal on both sides of the drum.