Voltage regulation - bulb or resistor?

[VicMallows]

The only use I can think of for a bulb is a current limiter

Precisely! and they were often used for exactly that before it became cheaper and easier to do it with semiconductors. Remember fluorescent lights which used a lamp bulb rather than an inductor as ballast? (totally inefficient....but electricity was cheap then. and the extra heat probably welcome too).

Vic