Choke and Throttle

John Tranter with his father, c.1947
John Tranter with his father, c.1947

I can understand why the word “choke” is used for a car’s choke: it chokes off the air flow, making the air-fuel mixture richer (less air, therefore more fuel) which is needed when the engine is cold. Well, it’s not needed these days, but every vehicle had a choke (and a crank-handle) when I was a kid, back in the Middle Ages.

But why is a tractor’s throttle called a “throttle”? It does the opposite of throttle; instead of throttling back the flow of the air-fuel mixture to the engine, it is used to increase it.

Beats me.