What it does. This is not easy to explain to women and the mechanically innocent....
More from the article:
Under the hood there's a shiny hunk of mechanism, smaller than a breadbox, that houses a reversible electric motor, a flyball governor, and associated electrical gadgetry. A flexible shaft resembling a speedometer cable feeds in car-speed information; a rod leading to the carburetor linkage executes commands to the throttle.
What's a breadbox?