 
| ▲ Vacuum | 
Well, AIR sign more like it. After a little bit of crappy glassbending, I managed to get some vaguely recognisable letters together to spell out....


It's running off a 30kV flyback power supply. Incidentally, I stuck a meter in the circuit and found that around 3mA of current was flowing. 3mA @ 30kV = 90W; not bad for a flyback.
30/11/10: Obviously, the tube will not actually have 30kV across when it's lit, so this figure is wrong.
| ▲ Vacuum |