The servant of Philon is a humanoid robot from the 3rd century BC designed to pour and mix wine and water whenever a cup was placed in the statues hand. The robot first pours the wine, and then dilutes it with water, using pipes hidden within the robot leading up its arm and into its central chamber, around where the stomach would be. Flow is started or stopped by opening and releasing air valves above the fluid reservoirs, which allowed or prevented flow by causing a vacuum. Placing the cup into the robot's hand would cause the arm to lower and the air valves to open; as it poured the robot would lower and eventually the air valve would close again.
Two submersible bridges were constructed at either end of the Corinth Canal in Greece. To let ships pass through the canal, the bridges' decks are lowered 26 feet below the water level. This allows for ships of any height to pass through the canal, as there is no bridge structure above the canal to interfere with ships' masts, sails, or other parts of the ships. However, since the canal was constructed in the late 1800s, the canal is too narrow for some modern ships to pass through. Even with this constraint, approximately 11,000 ships go through the canal each year.
Sources:
Allen, David H. How Mechanics Shaped the Modern World. 2014.
By Original: Aspiasia Coumiotis Derivative work: Spilla at English Wikipedia (File:BridgeSubmerging.jpg) [CC BY-SA 2.5 (https://creativecommons.org/licenses/by-sa/2.5)], via Wikimedia Commons
