There was also some concern about the luminescent dial that glowed green in the dark. This effect came from a small glass tube of tritium gas, which gave off beta radiation and made the dial fluoresce. Although the radioactivity was equivalent only to that given off by a wristwatch it was felt wise to withdraw this facility as public concern over radioactivity grew.
Trimphone - Wikipedia, the free encyclopedia
Wonder where all the old ones are stored.
