Even today they don't make reliable filaments either, long or not. I have a
couple of display cabinets with the filament strip lights behind a baton.
although the filaments are supported every inch or so along the tube they
used to fail very fast. I now run two in series which I'm told gives off a
nice golden light which makes the crystal sparkle better.
Brian

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This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please
Note this Signature is meaningless.!
"harry" wrote in message
...
On Monday, 14 January 2019 07:12:58 UTC, D.M. Procida wrote:
I bought a lightbulb (and a ceramic holder and rotary lightswitch) in a
second-hand shop yesterday. They had many beautiful items taken from an
old electronics teaching laboratory - all brass, steel, ceramic and
wood.

The lightbulb:
https://www.dropbox.com/s/qw0vnqdtvemf0ld/lightbulb.jpg?dl=0.

It's about 10cm tall, and has an Edison screw. The filament loops up and
down the bulb in six lengths. It's made by Osram, but there are o other
readable markings on it.

Any idea what the purpose of a lightbulb like this might be?

I'm tempted to run it at low voltage to see what it looks like
illuminated, but I'd hate to damage the filament.

Daniele

It's just old. Intended to go in a floodlight.
In days of yore they couldn't make reliable thin tungsten filaments so
they had to be long.
It IS interesting.