I have a picture of an intake/exhaust setup from a '46 Chevy COE. I have put a red oval around what I think is a govenor, can someone verify this for me?

If it is...why would you use one of these types of devices?
How does it work?

Thanks,
Chevman

Click this link to see the manifold....or just look at the picture here....
[IMG]http://thumb17.webshots.net/t/52/552/3/63/0/2503363000061479077oNundd_th.jpg[/IMG]