Re: strength of vacuum

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: Ed Phillips <evp-at-pacbell-dot-net> 

Tesla list wrote:
 >
 > Original poster: Bert Hickman <bert.hickman-at-aquila-dot-net>
 >
 > Tesla list wrote:
 >
 > >Original poster: Ed Phillips <evp-at-pacbell-dot-net>
 > >Tesla list wrote:
 > >  >
 > >  > Original poster: Bert Hickman <bert.hickman-at-aquila-dot-net>
 > >  >
 > >  > Antonio and all,
 > >  >
 > >  > I've found that some elongated lamps that are intended for scroll 
lamps do
 > >  > indeed have a high vacuum instead of inert gas. The glass fluoresces a
 > >  > brilliant yellow-green color, especially if the filament becomes
 > >  > incandescent from field emission (with lots of electrons being
 > > emitted). An
 > >  > old antique light bulb I have does a similar thing, only the glass
 > >  > fluoresces a brilliant blue color. In either case, I could easily 
detect
 > >  > the presence of X-rays via a Geiger counter 8 feet away. Remember that
 > >  > distance is your friend (inverse square law), keep run times down, or,
 > >  > preferably, don't irradiate yourself at all... :^)
 > >  >
 > >  > Best regards,
 > >  >
 > >  > -- Bert --
 > >     What is a scroll lamp and where do you get those bulbs?
 > >Ed
 > >
 > >.
 >
 > Hi Ed,
 >
 > It would probably help if I called it by its proper name - tubular
 > incandescent light bulb... :^)  They are used in some desk lamps, display
 > cabinets, and even exit signs and the 25W one I have looks just like one of
 > these:
 > http://www.abclights-dot-com/tubulart10std.html
 >
 > The bulb I have came from the local hardware store, and apparently is
 > evacuated and not backfilled. I tried to find a brand name it but all it
 > says on the base is "120V 25W China"... :^)
 >
 > Best regards,
 >
 > -- Bert --

	Fine; I suspected that was what it was.  Have a couple here but they're
US made and probably gas filled.  Will check the local "98 cent" store
(not "99", all Chinese stuff which is priced very cheaply and worth
about what it costs) to see if they have any.  If so will play around
with it.

Ed