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smallneon.jpg (1451 bytes)smallglass.jpg (1038 bytes)Geissler Tubes

These intricate glass gas-filled tubes were made in the early 1900s, as a scientific curiosity for use with the induction spark coils which were popular at the time. My tubes below are all 5-6" long. Larger and more intricate tubes were made, in sizes up to 18", with the glass tube formed into all sorts of twists, bows and spiral shapes.

The inverter modules for cold-cathode flourescent (CCFL) LCD panel backlights work very well for powering geissler tubes, although you shouldn't use them for extended periods as they probably over-drive the tubes - they get warm pretty quickly!

Original 1914 advertisment for geissler tubes here  More Geissler tubes here  Large collection of geissler and crookes tubes

 

gies1.jpg (4868 bytes)Spiral tube - half the spiral is made of uranium glass, which fluoresces with a green colour.

gies2.jpg (7245 bytes)Wobbly tube, with centre section made of green uranium glass.

geis3.jpg (5659 bytes)The high frequency supply causes this 'dotting' effect - the size and spacing varies with voltage and frequency.

geisnfg.jpg (4332 bytes)Intricate tube, unfortunately the sealing pip was broken so it doesn't work.

nfg2.jpg (4294 bytes)Another dead tube.(moral : always carry a high-voltage tester when buying!).

geisliq2.jpg (3958 bytes)Liquid filled tube, only lights very weakly - probably leaky.

repgeis.jpg (4951 bytes)Replica tube, 10" long (details at bottom of page)

geisliq.jpg (6020 bytes)This tube has an outer sleeve containing a clear liquid, which gives a blue hazy glow surrounding the inner spiral.

I mounted this one on a small box containing an infra-red receiver and an inverter from an LCD panel backlight, lighting the tube whenever you fire the TV remote at it.

giesgl1.jpg (3239 bytes)A couple of two-section tubes, the lower one having  different gases in each of the two sections. The sections are capacitively coupled by the co-axial globe section in the middle

geisgl2.jpg (3974 bytes)Varying the voltage and frequency produces a wide variety of different patterns of coloured and dark zones.

disch1.jpg (3554 bytes)A couple of other gasfilled discharge tubes, with capillary sections which glow very brightly.

disch2.jpg (3682 bytes)

 

 

ausgeis.jpg (20100 bytes)Tube with four liquid-filled sections, at the Powerhouse Museum Sydney.

Below are some amazing geissler tubes from the Pressler Collection, pictures courtesy of David Stanley Auctioneers. Sizes (left to right): 19", 18", 36" and 15" high.

pgeis1.jpg (35793 bytes)pgeis2.jpg (27867 bytes)pgeis3.jpg (37060 bytes)

Sources

Replica tubes available from this German supplier (Babelfish translation)

Just Neon replica geissler tubes.

Several people have asked me where to find Geissler tubes - I got most of mine from an auction of scientific antiques at Christies, so you should check out the larger auction houses for sales of scientific antiques, and also scientific antiques dealers.

There are a couple of London based scientific antiques dealers who have shops open on Saturday mornings in the Lipka Gallery, off Westbourne Grove at Portobello road market, both of whom I've seen offering Geissler tubes at specialist antique fairs  :

Scientific & Antique Ltd. Nick Webster Tel. 20 8742 9002, Office 22-24 Ariel Way, White City, London W12 7SH

Scientific & Medical Antiques : Desmond & Elizabeth Squire 020 8946 1470, Fax 020 8944 7961, PO Box 4252, London SW20 0XS

http://www.earlytech.com/ - on-line antiques sales and auctions, with sections for scientific/electrical items.

Edmund Scientific (New Jersey USA (609) 573-6250), and probably other educational scientific suppliers, sell straight capillary discharge tubes like those at the bottom of the page with a variety of different gas fillings.

I also found a source of replica Geissler Tubes, as well as other replica discharge tubes and early valve replicas, pictured below. I saw these at the National Vintage Communications Fair in Birmingham UK (10 May 1998). The geissler tube replica was 50, other prices below are from memory.

The replica Geissler tube I bought (pictured above) is about 10" long, with 6mm tubing - a bit larger & thicker than you tend to see in original tubes. The replica has excellent detail, down to the electrode and seal appearance, although the end-caps look like standard valve anode caps rather than the more normal cap and loop terminals.

 

replica1.jpg (20372 bytes).



replica3.jpg (12977 bytes)replica4.jpg (9196 bytes)Replica R valve and another early valve .either 40 or 90 - I couldn't read the label & forgot to ask! These look really nice - the. photos don't do them justice!

 
smallneon.jpg (1451 bytes)smallglass.jpg (1038 bytes)


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