I need some help sourcing the metal fitting in the picture:
http://ecx.images-amazon.com/images/I/310e-2lm8RL._SY355_.jpg

It's 7/16 OD, thin wall brass.  It matches K+S stock tubing except that the
end is rounded off and closed.
http://www.hobbylinc.com/htm/k+s/k+s8137.htm

The diameter is critical, the fitting it goes in doesn't flex much.

I am not too picky on length, more than half is good, more than an inch is
a problem.

A hole in the closed end is actually good, but not critical.

Someone somewhere makes these things, it's probably some common thingus
used on something I've never heard of.   Can anyone here match it up with
something?

Jewlery fittings are close, but all I've seen are too small in diameter and
only about 1/4" long.



Why:

I have an antique "Violet Ray" device that I would like to make some ends
for.  It's a rare one, which runs from 32V "farm current".  Such devices
were made by the truckload around the turn of the century, to cure whatever
ailed you, but the vast majority are 110 or 220V for europe.  The farm
current device is unique.

I could just go buy something like in the pic, but I want to make something
more like a geissler tube, which is a bit of a project.  To that end, I've
taken up glassblowing, found a source of uranium glass, built a vacuum
manifold and "filling station" and learned to seal off these tubes when
under vacuum of 1-10 torr.

On Ebay, there is a set of Christmas lights that are for 32V farm current,
starting bid is $750 for eight lamps in a string.
http://www.ebay.com/itm/Vintage-Christmas-Lights-Delco-Farm-32-Volt-Noma-4-=
Volt-Mazdas-Extremely-Rare-/171975314757?hash=3Ditem280a870d45:g:~rcAAOSw5V=
FWHB7f

Apparently the decision for 32V went along the lines that farmers generally
suck at being electricians, so 32V isn't too bad on I^2R losses, but low
enough for few fried farmers.  Standard 110V plugs and switches were used
though, which could get exciting if you took your farm device and plugged
it in on a trip to the big city.
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