The Cathode Ray Tube site
History and Physics Instruments
The first discharge light
Johann Heinrich Wilhelm Geissler (1815-1879)
Born in Igelshieb, was a skilled glassblower from an glass art making family in Thuringen Germany and 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 a 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 practical discovery of the first discharge light. Someting that was until then only possible in instruments like "electric eggs". The Geissler tubes where sold for demonstrations at Universities, schools and later on even for home-entertainment use. This was a rare phenomena in the time that there was only electric carbon and gas light.
Geissler solved the "metal electrode trough glass problem" by using (expensive) platinum wire in a small lead glass seal which was melted into the soft sodalime glasswall of the tube. In the beginning of the 20th Century until the thirties Geissler tubes were produced by many glassblowers like Franz Müller (Geissler's Nachfolger), Greiner & Friedrichs, Rudolf Pressler and Richard Müller-Uri.
In France and and Britain also many scientific workshops started the production of these instruments. 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 or wimshurst machine, 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 biography of Heinrich Geissler can be found here.
A small 10cm Geissler tube with transparent fluorescent liquid in a second glass jacket.
Tube filled with quinine solution for a bright Blue colour.
Close-up of the interior of a Geissler tube filled with a fluorescent liquid under influence of UV light.
20cm Geissler tube with unknown liquid
15cm Geissler tube with magdala red liquid
15cm orange liquid Geissler tube
Early 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.
A rare old waffle or grid tube
This small 15cm high tube from the beginning of the 20th century has a partly uranium glass waffle and filled with a liquid.
Tube under UV light.
The liquid becomes misty.
Small Geissler tube with stratification effect filled with fluorescein liquid.
Picture from the 1924
Becker & Co catalogue.
Product of Pressler.
20cm double trumpet tube with fluorescein liquid.
20cm Geissler tube with twists filled with orange liquid
20cm Geissler tube with spiral filled with fluorescein.
Geissler tube with stratifications
Four branch Geissler tube
A small 30 cm model with four different colored liquids.
Large 30 cm Geissler tube ca 1900.
The tube can be filled with colored liquid, in this case Fluorescein.
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Liquid filled tubes
Geissler tube length 27cm filled with Rhodamine pink-red.
Geissler tube length 27cm filled with Rhodamine orange.