Johann Heinrich Geissler
was a magnificent glassblower from a glass making family in Thuringen Germany,
were he was a travelling instrument maker. After a decade he opened a shop in
Bonn in 1855 to sell his scientific apparatus to schools and universities. In
that same time Geissler developed a mercury vacuum pump, with this instrument he
was able to take the most of the air out of the glass tubes and did experiments
with rarified gas. When he now applied high tension to this tubes they produced
a luminous effect. This was the discovery of the first discharge light, in
that time the beautiful tubes where used for demonstrations at Universities,
schools and later on even for entertainment-home use. In the time that there was
only carbon light this was a rare phenomena. Also high vacuum tubes were now
possible to make, this led to many discoveries of physical instruments like the
different Crookes, Hittorf and Goldstein tubes. In the beginning of
the 20th Century 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. 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, they are however still made by some glassblowers in Germany.
The British Science Museum in London displays
top art from Heinrich Geissler. In Thuringen / Cursdorf there is a also museum dedicated to Geissler's work. The complete
biography of Geissler can be found on the excellent site of Eugenii Katz.
Johann Heinrich
Geissler 1815-1879
In these three
Christie's catalogues you can find a lot of amazing tubes.
The
Christie's catalogue from 1998 contains a great collection of Geissler and
Crookes tubes from the former Pressler factory. Made before WWII, a
part of the produced tubes were stored in other buildings for secure
reasons but they were forgotten for a long time. After the war in the
DDR time the factory was renamed in VEB and produced mainly
radiometers. When the Berlin wall fell, the stored tube collection was
rediscovered. That's one story... the other is that the tubes were made
after WWII by former Pressler employees with remaining part stock of
the old Pressler factory, so the tubes are not antique or old. Due to
this fact Christie's cancelled the auction, but the catalogue was
already made at that time. The tubes, some times for sale at auction sites, are
still fine examples of the old glassblowing skills and are true
collector items.
An
old drawing of different types of Geissler tubes.
A
small 10cm Geissler tube early 20'th century with transparent fluorescent fluid
in a second glass jacket.
Close-up of the interior of the Geissler tube under influence of
UV light.
Different end caps
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 from the late 19th and beginning of the 20th century are equipped with
wire loops, followed by small copper or brass caps, later on 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 the tube an enhanced effect. Some bigger tubes can be externally
filled in a separate chamber around the vacuum tube to experiment with different
fluids.
Quinine, a light yellow fluid - bright blue fluorescent.
Fluorescein. yellow fluid. Rosaniline, magenta fluid. Magdalared or
Sudanred, red fluid.
Glass The early old tubes are made of soft
soda lime glass. The tubes which are made today are made of modern Pyrex
glass.
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.
The
Cathode Ray Tube site
A Spectral tube
emits certain wavelengths of light (color) in the capillary-thin tube
in the middle. This color depends on the type of noble gas or vapor
inside the tube. The different spectra of colors can be seen by use of
a prism. These tubes were used for spectroscopy classroom
demonstrations.
Spectral tubes (Pressler)
Activated Pressler spectral CO tube.
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. 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)
2
small 10cm early Geissler tubes with original box.
Another example of an early liquid-filled Geissler
tube.
Fine
early Geissler twist tubes with uranium glass.
Details in the centre.
Standing Geissler tube with uranium glass
twist.
Geissler tube with red fluid
Neon
Helium
Argon
Mercury
Nitrogen
Oxygen
Hydrogen
The
Nicholas Webster Collection Christie's 29 sept 1991
From
the workshop of Rudolf Pressler of Cursdorf Christie's 18 febr
1998
The
Bryan Richmond-Dodd Collection Christie's 24 June 1999