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

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.

On 14/01/2019 07:12, 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?

"Let There Be Light"

Looks to be an old cylinder filament bulb - c.f. modern versions such as

https://www.hollowaysofludlow.com/sh..._filament_bulb


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



--
Robin
reply-to address is (intended to be) valid

In article ,
(D.M. Procida) writes:
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.

It was a standard physics laboratory supplies lamp, used to make
an image of the filament in things like pin-hole viewers/cameras.

It might not be mains voltage. If it's an uncoiled filament, it
isn't long enough. If it's a single coiled filament, it might be.

Measure the filament resistance with a test meter.
V^2/(resistance * 15) will give you the approx power rating
assuming a tungsten filament. (The times 15 is to correct for the
temperature change when running, although it may be too high a
factor for such a stretched filament lamp.)

It is sort of mimicing the original squirrel cage filament lamps,
but those were far too fragile to be used in a lab where they
would likely be moved around.

The other type of lamp used for this were carbon filament lamps,
but the filament in yours is far too long and floppy to be a
carbon filament lamp. (They are usually 2 - 4 loops, unsupported.)

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

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

--
----- --
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.

harry wrote:

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.

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

So likely to be a high-powered, standard mains voltage bulb?

I assume it would not come to any harm run at a lower voltage, though I
know that some lamps can darken as the result of deposits on the inside
of the glass when run dimmed.

Daniele

On 14/01/2019 09:12, Andrew Gabriel wrote:
In article ,
(D.M. Procida) writes:
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.

It was a standard physics laboratory supplies lamp, used to make
an image of the filament in things like pin-hole viewers/cameras.

It might not be mains voltage. If it's an uncoiled filament, it
isn't long enough. If it's a single coiled filament, it might be.

I thought hairpin style filaments weren't coiled - hence the tubular
design (up to at least 8 inches long IIRC) to make them long enough.


Measure the filament resistance with a test meter.
V^2/(resistance * 15) will give you the approx power rating
assuming a tungsten filament. (The times 15 is to correct for the
temperature change when running, although it may be too high a
factor for such a stretched filament lamp.)

It is sort of mimicing the original squirrel cage filament lamps,
but those were far too fragile to be used in a lab where they
would likely be moved around.

The other type of lamp used for this were carbon filament lamps,
but the filament in yours is far too long and floppy to be a
carbon filament lamp. (They are usually 2 - 4 loops, unsupported.)



--
Robin
reply-to address is (intended to be) valid

On 14/01/2019 09:31, D.M. Procida wrote:

snip

So likely to be a high-powered, standard mains voltage bulb?

If it is mains, there probably wasn't a 'standard' supply voltage when
it was made.

I assume it would not come to any harm run at a lower voltage, though I
know that some lamps can darken as the result of deposits on the inside
of the glass when run dimmed.

Daniele


Cheers
--
Clive

On Mon, 14 Jan 2019 08:12:54 +0100,
(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.

Possibly a decorative low current lamp such as these modern version.

https://www.lightingstyles.co.uk/e27...ent-amber-lamp

https://www.dowsingandreynolds.com/s...long-filament/

The filament usually only glows, you can see the amount of slack in
them, anything much more than the power needed to make them glow would
also make them expand, sag and break.

On Mon, 14 Jan 2019 10:31:56 +0100,
(D.M. Procida) wrote:

I assume it would not come to any harm run at a lower voltage, though I
know that some lamps can darken as the result of deposits on the inside
of the glass when run dimmed.

The darkening is metal vaporizing from the filament and settled on the glass.
The bulbs that habe a mechanisnm to avoid this are the halogen bulbs: the glass
is run hot, a halogen scrubs the metal off the glass, and re-deposits it on the
filament.

This is positively not a halogen bulb -- run it with as low a voltage as you
like.

The lifetime of a lightbulb is exquisitely sensitive to to voltage, something
like (voltage/ratedvoltage)^-12 to (voltage/ratedvoltage)^-14. So running a bulb
at 99% of the rated voltage will increase its life by 12-15%.


Thomas Prufer

On 14/01/2019 09:33, Robin wrote:

I thought hairpin style filaments weren't coiled - hence the tubular
design (up to at least 8 inches long IIRC) to make them long enough.

If you zoom in on the photo, you can see that this filament is coiled
quite loosely.

A modern tungsten filament bulb is double-coiled, ie the wire is wound
into a very fine spiral, and then that spiral is coiled again.

https://qph.fs.quoracdn.net/main-qim...d3a0ca379faa72

https://www.quora.com/Why-does-the-f...uce-more-light

On 14/01/2019 11:02, Thomas Prufer wrote:
On Mon, 14 Jan 2019 10:31:56 +0100,
(D.M. Procida) wrote:

I assume it would not come to any harm run at a lower voltage, though I
know that some lamps can darken as the result of deposits on the inside
of the glass when run dimmed.

The darkening is metal vaporizing from the filament and settled on the glass.
The bulbs that habe a mechanisnm to avoid this are the halogen bulbs: the glass
is run hot, a halogen scrubs the metal off the glass, and re-deposits it on the
filament.

There was a "fashion" (in the late 80s I think) for cars to have
dim-dipped lights - in fact I think it was a legal requirement at one
time - where, with the ignition on and sidelights on, the headlamp bulbs
were connected in series (for more light in dusk I assume). This was
supposed to have shortened the lives of the halogen bulbs used at the time.

--
Max Demian

On 14/01/2019 11:21, GB wrote:
On 14/01/2019 09:33, Robin wrote:

I thought hairpin style filaments weren't coiled - hence the tubular
design (up to at least 8 inches long IIRC) to make them long enough.

If you zoom in on the photo, you can see that this filament is coiled
quite loosely.

My terminological failu I grew up with "coiled" as shorthand for
coiled-coil, never having met a lamp that was a _single_ straight wire.
Indeed, ones like Daniele's which clearly has the filament passing up
and down were sometimes called "straight wire".





--
Robin
reply-to address is (intended to be) valid

On 14/01/2019 11:02, Thomas Prufer wrote:
On Mon, 14 Jan 2019 10:31:56 +0100,
(D.M. Procida) wrote:

I assume it would not come to any harm run at a lower voltage, though I
know that some lamps can darken as the result of deposits on the inside
of the glass when run dimmed.

The darkening is metal vaporizing from the filament and settled on the glass.
The bulbs that habe a mechanisnm to avoid this are the halogen bulbs: the glass
is run hot, a halogen scrubs the metal off the glass, and re-deposits it on the
filament.

This is positively not a halogen bulb -- run it with as low a voltage as you
like.

The lifetime of a lightbulb is exquisitely sensitive to to voltage, something
like (voltage/ratedvoltage)^-12 to (voltage/ratedvoltage)^-14. So running a bulb
at 99% of the rated voltage will increase its life by 12-15%.


Thomas Prufer


When I moved to my current house in 1991, the bathroom had one of those
nasty fittings with three 40-watt reflector bulbs that gave out rubbishy
illumination.

I replaced it with a standard BC fitting and stuck in a 60-watt clear
Woolworths bulb as a temporary measure so I could see what I was
doing when shaving. (bulb marked 240 volts).

It's still there and working fine.

On Mon, 14 Jan 2019 08:12:54 +0100,
(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.

Could it be for a cine film projector?

On 14/01/2019 12:54, Scott wrote:
On Mon, 14 Jan 2019 08:12:54 +0100,
(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.

Could it be for a cine film projector?

Unlikely. Projector lamps and theatre lamps the old T1 theatre lamp
Had a 3 inch or so glass gl;obe but a compcet filamjent of less than 1
inch square. I was using thesesat least until the 80's. The coimpace
filament was needed to be able to focus the light into a beam.

Malcolm

---
This email has been checked for viruses by AVG.
https://www.avg.com

On Monday, 14 January 2019 12:54:50 UTC, Scott wrote:
On Mon, 14 Jan 2019 08:12:54 +0100,
(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.

Could it be for a cine film projector?

Film projectors prefer small light sources eg carbon arc. It might have been used for an old slide projector, especially if it's 250W-1kW. Tungsten bulbs run a century if kept very dim.

Rotary switches were usual very early, possibly pre-1900. But they never completely went away.


NT

Robin wrote:

It was a standard physics laboratory supplies lamp, used to make
an image of the filament in things like pin-hole viewers/cameras.

It might not be mains voltage. If it's an uncoiled filament, it
isn't long enough. If it's a single coiled filament, it might be.

I thought hairpin style filaments weren't coiled - hence the tubular
design (up to at least 8 inches long IIRC) to make them long enough.

It is indeed coiled.

Daniele

In article ,
Robin writes:
On 14/01/2019 11:21, GB wrote:
On 14/01/2019 09:33, Robin wrote:

I thought hairpin style filaments weren't coiled - hence the tubular
design (up to at least 8 inches long IIRC) to make them long enough.

If you zoom in on the photo, you can see that this filament is coiled
quite loosely.

My terminological failu I grew up with "coiled" as shorthand for
coiled-coil, never having met a lamp that was a _single_ straight wire.
Indeed, ones like Daniele's which clearly has the filament passing up
and down were sometimes called "straight wire".

The squirrel cage filament lamps were not coiled, but had a
significantly longer filament than the lamp in the picture.

The double-ended tubular 30W and 60W filament lamps are single
coil to make the filament long enough. They are normally vacuum
tubes too, as any gas fill has a significant cooling effect
on such a long filament and it wouldn't get up to temperature.
To compensate for lack of gas fill, the filaments are underrun
to avoid the tungsten subliming too fast, but that also makes
them horribly inefficient, and they were still only rated 750
hours. Altogether, a bad idea.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On 14/01/2019 15:45, Andrew Gabriel wrote:
In article ,
Robin writes:
On 14/01/2019 11:21, GB wrote:
On 14/01/2019 09:33, Robin wrote:

I thought hairpin style filaments weren't coiled - hence the tubular
design (up to at least 8 inches long IIRC) to make them long enough.

If you zoom in on the photo, you can see that this filament is coiled
quite loosely.

My terminological failu I grew up with "coiled" as shorthand for
coiled-coil, never having met a lamp that was a _single_ straight wire.
Indeed, ones like Daniele's which clearly has the filament passing up
and down were sometimes called "straight wire".

The squirrel cage filament lamps were not coiled, but had a
significantly longer filament than the lamp in the picture.


Pointed cap donned


--
Robin
reply-to address is (intended to be) valid

On 14/01/2019 07:12, 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 a Cathermin tube with an indium complex of +4.

Used in an Interocitor.

On 14/01/2019 20:27, mm0fmf wrote:
On 14/01/2019 07:12, 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 a Cathermin tube with an indium complex of +4.

Used in an Interocitor.

One presumes you must be old enough to recall the film "This Island Earth"?

On 14/01/2019 21:20, Fredxx wrote:
On 14/01/2019 20:27, mm0fmf wrote:
On 14/01/2019 07:12, 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 a Cathermin tube with an indium complex of +4.

Used in an Interocitor.

One presumes you must be old enough to recall the film "This Island Earth"?

One of best, if not the best, 1950's SF film. It's fun and entertaining
whilst films like The Day The Earth Stood Still are too serious. The
original is excellent and the MST3000 skit is priceless.

Use your intensifier disk on YouTube to enjoy it if you don't have it on
DVD. ;-)

On 14/01/2019 21:30, mm0fmf wrote:
On 14/01/2019 21:20, Fredxx wrote:
On 14/01/2019 20:27, mm0fmf wrote:
On 14/01/2019 07:12, 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 a Cathermin tube with an indium complex of +4.

Used in an Interocitor.

One presumes you must be old enough to recall the film "This Island
Earth"?

One of best, if not the best, 1950's SF film. It's fun and entertaining
whilst films like The Day The Earth Stood Still are too serious. The
original is excellent and the MST3000 skit is priceless.

Use your intensifier disk on YouTube to enjoy it if you don't have it on
DVD. ;-)

Has it stood the test of time like Forbidden Planet?

Andrew Gabriel wrote:
In article ,
(D.M. Procida) writes:
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?


It is sort of mimicing the original squirrel cage filament lamps,
but those were far too fragile to be used in a lab where they
would likely be moved around.

Squirrel cage lamps were for many years the std fitment for ships
navigation lights as they gave a nice even light distribution, they often
move around a fair bit especially at the top of a mast so I dont think
they were that fragile.

GH

In article ,
Max Demian wrote:
There was a "fashion" (in the late 80s I think) for cars to have
dim-dipped lights - in fact I think it was a legal requirement at one
time - where, with the ignition on and sidelights on, the headlamp bulbs
were connected in series (for more light in dusk I assume). This was
supposed to have shortened the lives of the halogen bulbs used at the time.

Common on London taxis - but they used the all in one Lucas sealed beam
unit, which wasn't halogen.

These days that same unit on full looks like dim dip.

--
*Why do overlook and oversee mean opposite things?

Dave Plowman London SW
To e-mail, change noise into sound.

On 14/01/2019 21:30, mm0fmf wrote:
On 14/01/2019 21:20, Fredxx wrote:
On 14/01/2019 20:27, mm0fmf wrote:
On 14/01/2019 07:12, 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.

It's a Cathermin tube with an indium complex of +4.

Used in an Interocitor.

One presumes you must be old enough to recall the film "This Island
Earth"?

One of best, if not the best, 1950's SF film. It's fun and entertaining
whilst films like The Day The Earth Stood Still are too serious. The
original is excellent and the MST3000 skit is priceless.

I've often wondered where the title comes from. It sounds like a
quotation, but I can't trace it.

--
Max Demian

On 14/01/2019 23:50, Fredxx wrote:
On 14/01/2019 21:30, mm0fmf wrote:
On 14/01/2019 21:20, Fredxx wrote:
On 14/01/2019 20:27, mm0fmf wrote:
On 14/01/2019 07:12, 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 a Cathermin tube with an indium complex of +4.

Used in an Interocitor.

One presumes you must be old enough to recall the film "This Island
Earth"?

One of best, if not the best, 1950's SF film. It's fun and
entertaining whilst films like The Day The Earth Stood Still are too
serious. The original is excellent and the MST3000 skit is priceless.

Use your intensifier disk on YouTube to enjoy it if you don't have it
on DVD. ;-)

Has it stood the test of time like Forbidden Planet?

Forbidden Planet is a great film but is "stiff" in comparison and
whenever I see Leslie Nielson, even when he's young, I expect him to
break into a Frank Drebin Police Squad routine.