1930s Neon salesman's sample case - photo

1930s Neon salesman's sample case.

https://diqn32j8nouaz.cloudfront.net...esman_case.jpg


Previously:

https://www.homemadetools.net/forum/...116#post141296
https://www.homemadetools.net/forum/...250#post150146

Neon glows red. Other gases produce the different colors...