Ball Turning Tool
This is a device which is used to turn a spherical ball on a lathe, it is quite basic in it's operation in that it attaches to the lathes cross slide and is fed into the work and then operated by the long handle.
This was designed to take some cheap carbide turning inserts that I guess will last for some time, here is an example of a ball handle created in stainless steel using the ball turning tool.