Interesting lamp, did James contribute/work on this particular one or was it just made at Sylvania's Tienen factory, Belgium, where he worked at the time? Anything special about it beside its phosphor blend of yttrium vanadate and YAG (which was also used by other manufacturers such as Philips and Osram)?

By the way, you list "ceramic arc tube" as the radiator type for all your mercury lamps... this must be a mistake as in all those cases the burner is made of fused quartz, also known as amorphous silica, which is not a ceramic material.

Max, pardon my idiocy! For whatever odd reason I filled in Ceramic, when obviously it is a Quartz-based material (and hence the development of QMH...) That is fixed on this picture, and will be fixed across the board shortly.

Regarding James and his possible contribution to the production of this lamp, I would say he likely oversaw some kind of quality control standards, considering how much effort he put into his posts documenting the life-test rack of mercury lamps at Sylvania Belgium. I need to reach out and ask if his specific focus at some point in time was mercury, but it seems probable, considering his background in HID development at the likes of GE and EYE-Iwasaki prior to joining Sylvania. Thanks for your comment.

Don't beat yourself up, it's just a mistake, not idiocy Another interesting point to consider is the fact that the quartz material of the burner is not what radiates the light we see (so it's certainly not the radiator considered here in the description), it's the internal arc burning in mercury vapor plus the fluorescence of the phosphor coating which do (in the specific case of the present lamp, that is).

Now you're just being picky, Max

If I was too picky indeed then Maxim was right, that was not just a mistake. That's a bit harsh of you, isn't it?

Maybe a little bit