Name for Object/Device with Electric Light Between Two Rods

[UserNameHere]

I don't know the name of the object/device, but I have seen them before. I'll try to describe it as best I can, so bare with me. It is made of two straight wires - one to three feet in length - with some sort of power source connected to it. The two wires make a "V" shape with the small end attached to a power source. An "electric light" connecting from one wire to the other travels up the wires until it reaches the end of the two wires and then disappears. (it begins at the small end and grows larger until it reaches the open end) I know this is a terrible description, but I don't know much about it and I would like to learn how it works. All I need to know is what it is called, then I can look it up myself.

Thanks
James

EDIT: The two "wires" are stiff, so they look more like small rods rather than wires.

 

[Nabeshin]

http://en.wikipedia.org/wiki/Spark_gap#Visual_entertainment

Commonly called a Jacob's Ladder.

 

[Rap]

Jacob's Ladder

 

[UserNameHere]

Perfect, exactly what I was looking for. Thanks!