The Cathode Ray Tube site
electronic glassware
History and Physics Instruments
electronic glassware
History and Physics Instruments
Geissler tubes
The first discharge light
The first page
The first discharge light
The first page
Johann Heinrich Wilhelm Geissler, born in Igelshieb, was a skilled glassblower from a glass art making family in Thuringen Germany, he worked as a travelling instrument maker in Germany and the Netherlands. Geissler opened a small company in Bonn in 1852 to sell his self made scientific glass instruments to schools and Universities. In that same time he developed the mercury vacuum pump, with this instrument he was able to create an higher vacuum (2 Torr) than possible that time with standard equipment. This new developed vacuum pump enabled the production of high vacuum tubes which led to many discoveries of new physics instruments like the different Crookes, Hittorf, Goldstein and X-ray tubes.
Geissler experimented with different gasses in vacuum tubes, together with Julius Plücker who worked with him and named them Geissler tubes. When he applied high tension to the tubes they produced a bright luminous effect which was demonstrated for public in 1864 together with his new mercury vacuum pump. This was the discovery of the first discharge light, in that time the Geissler tubes where sold for demonstrations at Universities, schools and later on even for home-entertainment use. In the time that there was only electric carbon light, this was a rare phenomena. In 1874 Franz Müller joined his firm in Bonn. Geissler solved the "electrode trough glass problem" by using (expensive) platinum wire in a small leadglass seal which was melted into the soft sodalime glasswall of the tube. In the beginning of the 20th Century until the thirties many Geissler tubes were produced by Rudolf Pressler who learned his skills in Leipzig and started in 1903 his Pressler company in Cursdorf-Thuringen Germany, an area of many other scientific glass making companies.
The tube makers often used uranium glass, fluorescent liquid and different types of rarified gas to make the most beautiful luminous compositions. The tubes where discharged by use of a Ruhmkorff coil, this produced the high tension needed to lighten the tubes. Geissler tubes are real pieces of art and are rare collectors items, the tubes are still made by some glassblowers in Germany.
The British Science Museum in London and the Dutch Teylers Museum in Haarlem displays original tubes from Heinrich Geissler.
In Thuringen / Cursdorf a museum is dedicated to Geissler's work. A more complete description of Geisslers life can be found here.
Geissler experimented with different gasses in vacuum tubes, together with Julius Plücker who worked with him and named them Geissler tubes. When he applied high tension to the tubes they produced a bright luminous effect which was demonstrated for public in 1864 together with his new mercury vacuum pump. This was the discovery of the first discharge light, in that time the Geissler tubes where sold for demonstrations at Universities, schools and later on even for home-entertainment use. In the time that there was only electric carbon light, this was a rare phenomena. In 1874 Franz Müller joined his firm in Bonn. Geissler solved the "electrode trough glass problem" by using (expensive) platinum wire in a small leadglass seal which was melted into the soft sodalime glasswall of the tube. In the beginning of the 20th Century until the thirties many Geissler tubes were produced by Rudolf Pressler who learned his skills in Leipzig and started in 1903 his Pressler company in Cursdorf-Thuringen Germany, an area of many other scientific glass making companies.
The tube makers often used uranium glass, fluorescent liquid and different types of rarified gas to make the most beautiful luminous compositions. The tubes where discharged by use of a Ruhmkorff coil, this produced the high tension needed to lighten the tubes. Geissler tubes are real pieces of art and are rare collectors items, the tubes are still made by some glassblowers in Germany.
The British Science Museum in London and the Dutch Teylers Museum in Haarlem displays original tubes from Heinrich Geissler.
In Thuringen / Cursdorf a museum is dedicated to Geissler's work. A more complete description of Geisslers life can be found here.
Johann Heinrich
Wilhelm Geissler
1815-1879
Wilhelm Geissler
1815-1879
A small 10cm Geissler tube early 20'th century with transparent fluorescent fluid in a second glass jacket.
Close-up of the interior of a Geissler tube filled with a fluorescent fluid under influence of UV light.
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Nice collection of 4 Geissler tubes and an early electrotherapy tube with uranium glass, predecessor of the violet ray tube.
Picture courtesy of Alastair Wright.
Picture courtesy of Alastair Wright.
Collection of 3 small Geissler tubes with uranium glass.
Uranium glass also called Vaseline glass was
widely used in Geissler tube production, it
contains uranium salts (uranium dioxide) this is
a natural product, when added to glass it gives a
nice green color. Under UV and influence or electrical
discharges the glass fluorescence brightly.
This is caused by the radioactive nature of the salt.
Unless the measurable radioactivity it's not harmful for
normal use, unless you eat it. (not recommended)
The Scientific Instrument Society has recently
published a paper, Uranuim Glass and Its Sientific Uses
by Paolo Brenni. PDF 1Mb
widely used in Geissler tube production, it
contains uranium salts (uranium dioxide) this is
a natural product, when added to glass it gives a
nice green color. Under UV and influence or electrical
discharges the glass fluorescence brightly.
This is caused by the radioactive nature of the salt.
Unless the measurable radioactivity it's not harmful for
normal use, unless you eat it. (not recommended)
The Scientific Instrument Society has recently
published a paper, Uranuim Glass and Its Sientific Uses
by Paolo Brenni. PDF 1Mb
An early fluid-filled Geissler tube.
Standing Geissler tube
with uranium glass twist.
with uranium glass twist.
Geissler tube with red fluid
Geissler/Crookes
tube dating.
tube dating.
End caps
It is difficult to date Geissler tubes and Crookes tubes, the electrode connection is often the most simple and reliable age mark.
The oldest tubes date from around 1870 to 1890 are equipped with platinum wire loops. Small brass end-caps followed the Platinum loops which easily broke off (which were later often refitted with end-caps) , these were already used 1895 as can be seen in the old catalogs from that time. The expensive Platinum wire was replaced in 1912 by cheaper Dumet wire, around 1930 larger nickel plated cylindrical end caps were used. The youngest tubes have end caps similar to the anode cap on regular radio tubes.
Fluids
The fluids used in old Geissler tubes give them an enhanced effect. Some bigger tubes can be externally filled in a separate chamber around the vacuum tube, to experiment with different fluids.
Here are some color examples:
Quinine, a light yellow fluid - bright blue fluorescent.
Fluorescein. yellow fluid.
Rosaniline, magenta fluid.
Magdala red or Sudan red, red fluid.
Glass
The early tubes were made of soft soda lime glass, there were differences in composition due to there local origin. German, French and English glass was used.
There were many glass sorts like crystal, kali, Duran and Berliner glass.
German soda lime glass fluorescence apple green at an (X-Ray) high vacuum.
Old English lead glass fluorescence pale blue.
Didym-Cer glass which fluorescence red.
Uranium glass which fluorescence green.
Lifetime
Geissler (and Crookes) tubes are not made for longtime use, due to outgassing of the metal electrodes, so over time the tube will lose some of its vacuum. Use them only shortly!
For a medium Geissler tube about 3000 Volts @ 1mA.
It is difficult to date Geissler tubes and Crookes tubes, the electrode connection is often the most simple and reliable age mark.
The oldest tubes date from around 1870 to 1890 are equipped with platinum wire loops. Small brass end-caps followed the Platinum loops which easily broke off (which were later often refitted with end-caps) , these were already used 1895 as can be seen in the old catalogs from that time. The expensive Platinum wire was replaced in 1912 by cheaper Dumet wire, around 1930 larger nickel plated cylindrical end caps were used. The youngest tubes have end caps similar to the anode cap on regular radio tubes.
Fluids
The fluids used in old Geissler tubes give them an enhanced effect. Some bigger tubes can be externally filled in a separate chamber around the vacuum tube, to experiment with different fluids.
Here are some color examples:
Quinine, a light yellow fluid - bright blue fluorescent.
Fluorescein. yellow fluid.
Rosaniline, magenta fluid.
Magdala red or Sudan red, red fluid.
Glass
The early tubes were made of soft soda lime glass, there were differences in composition due to there local origin. German, French and English glass was used.
There were many glass sorts like crystal, kali, Duran and Berliner glass.
German soda lime glass fluorescence apple green at an (X-Ray) high vacuum.
Old English lead glass fluorescence pale blue.
Didym-Cer glass which fluorescence red.
Uranium glass which fluorescence green.
Lifetime
Geissler (and Crookes) tubes are not made for longtime use, due to outgassing of the metal electrodes, so over time the tube will lose some of its vacuum. Use them only shortly!
For a medium Geissler tube about 3000 Volts @ 1mA.
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See many more fine Geissler tubes on the next pages!
Early Blue Geissler tube
with Catherine-wheel
with Catherine-wheel
Orange fluid Geissler tube
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One of the first drawings of Geissler tubes from the 1870 Ganot book of Physics.
The stratification of the light in these tubes was one of the most intriguing things for the researchers, it's origin, current, type of gas and pressure led to many discussions in the scientific papers.
The stratification of the light in these tubes was one of the most intriguing things for the researchers, it's origin, current, type of gas and pressure led to many discussions in the scientific papers.
A rare old waffle tube.
This small 15cm waffle tube from the beginning of the 20th century has a partly uranium glass waffle.
This small 15cm waffle tube from the beginning of the 20th century has a partly uranium glass waffle.
Tube under UV light.
The fluid becomes misty.
The fluid becomes misty.