Most air compressors either are reciprocating piston type, rotary vane or rotary screw. Each slot of the rotor is fitted with a freely sliding rectangular vane. Rolling piston forces gas against a stationary vane. The hot route may require changes in turbine blade/vane materials or better blade/vane cooling. Gear pumps trochoid pumps and vane pumps are all commonly used. It featured a single vane rotating through 270 degrees. The structure features a combination of sundials, a water clock, and a wind vane. Impingement cooling is also used in mid chord of the vane. It is believed the tower was topped with a weather vane. Dorian visits a tavern, where he falls in love with beautiful singer named Sibyl Vane. Other sensors use a spring-loaded vane. At its tip is the original weather vane. Buchanan instructs the monster to run cables to a weather vane on the roof. Gray meets and falls in love with budding young actress, Sibyl Vane. She designed the iconic "snow goose", the 750-pound bronze weather vane above the head house.