A vernier throttle is a throttle often used in aircraft. It uses a cable and a screw mechanism to provide the operator precise control over an engine's operation. The concept is similar in use to vernier calipers which have a primary operation for gross (large) movement, and a secondary operation for fine movement. Like many other inventions that bear his name, the Vernier throttle is based on the work of mathematician Pierre Vernier.
Vernier throttles are commonly used in aircraft. A similar mechanism is also used in reciprocating (gasoline) aircraft engines to set the mixture to an appropriate value for a given altitude.