Purple-ish small lamps in contract printers of yesterday...

[Clueless]

In the 1940's units such as the Morse had many on/off switches; white lights, and even red lights; but what were the special qualities of the small purple-ish lamps that are now hard to come by? I understand that contract printing was common, that dodging and burning-in was possible via which lamps were on. TIA

 

[Jim Noel]

I trust you have not been looking directly at those little bulbs as if they are what I think they are, they produce ultra-violet. In fact they produce so much UV they also make Ozone which you can smell.

When you look at them, un-powered, do they have a little flat disc near the top? If so they are useful, but do produce UV.

If I can pull the name out of my rusty trap memory, I will send it to you.
JIm