The Cathode Ray Tube site
History and Physics Instruments
The first page
Crookes Maltese Cross tubes
In front a small French Radiguet modell ca 1920 with the cross falling backwards, in the back a Pressler tube with the cross falling to the front.
The Maltese Cross tube (Crookes nr 9)
This is one of the most famous Crookes tubes.
The tube demonstrates that electrons go in a straight line
and don't go through metal. The cross can actually lay
down and stand up (mechanically). When the cross lies
down, the glass face of the tube emits a green glow when
the electrons strike the glass wall, when it's right up you
will see the shadow of the cross.
After a while due to fatigue of the glass the glow is less
strong, when the cross is tipped over at that time, the
previous unexposed glass glows brighter than the
Mineral tubes (Crookes nr 4)
After Crookes made his first announcement in 1879 he made a second one in 1881
about the fluorescent and phosphorescent properties of different materials in his (pdf)
article Discontinuous Phosphorescent Spectra in High Vacua.
Some minerals glow beautifully due to their fluorescent or phosphorescent behavior
when the tube is activated, phosphorescent means that the glow still continues for a
while if the excitation stops. Different samples of fluorescent minerals, shells, coral,
gemstones but even rubies and diamonds were used.
Another research from C.Doelter can be read in this (pdf) German article from 1911.
And the research of Goldstein on salts in this pdf .
Here is a list of some common used minerals in Crookes tubes.
bright green willemite
Johann Wilhelm Hittorf
1824 - 1914
Sir William Crookes (1832-1919)
Crookes paved the way for many discoveries. He worked as a Scientist in his own laboratory in London where he did all of his research and developed a range of different types of high vacuum tubes.
In "On radiant matter", a lecture to the British Association for the Advancement of Science at Sheffield, Friday August 22 1879, Crookes demonstrated 19 different tubes and discussed the fourth state of matter, plasma. Many of his tubes stood at the base of further discoveries like the X-ray tube and the Braun tube which developed later on into our well known TV tube.
Look here for a complete publication of William Crookes his work in the New York Times newspaper.
A biography of William Crookes can be found here.
Johann Willhelm Hittorf (1824-1914)
Hittorf was a German Physicist who studied in Bonn under Julius Plücker,
he was the German counterpart of William Crookes. In his early days at the Münster Academy Hittorf had to made much of his own tools and instruments due to a lack of availability and limited money of the Academy.
In this research lab he did extensive research on gas discharges and made
tubes with "absolute vacuum" as early as 1865. He showed them to
Geissler (before his publication in 1869) who replicated and sold these tubes.
Hittorf discovered even before Crookes in 1869 that cathode rays traveled in a
straight line and that the intensity of the rays gained with a lowering pressure. He also noticed the shadow on the glass wall when there was an obstruction the the path of the ray. Both Crookes and Hittorff were important researchers and shared knowledge on this subject. [101, 56]
The glass tube workshop of A.C. Cossor 1896.
To the left the workshop of Alfred Charles Cossor in
Clerkenwell London which would later became a
leading British valve manufacturer.
This photograph is made in 1896 while some of his
workers (children!) preparing the glass tubes. Cossor
was that time the only British firm who could make the
first X-Ray tubes which were higher qualified than the
common Crookes tubes and made the first British Braun
tubes in 1902.
Maltese Cross tube early 20th Century
Notice the difference of Anode connection placement compared to the other models.
Shell samples light up influenced by cathode rays.
Crookes tubes with minerals and shells
made by Pressler
Crookes mineral egg tube (Crookes nr 4) demonstrate the fluorescent behavior of stone and shell minerals or even mineral sand. This kind of tubes were made in different sizes.
Crookes mineral tube ca1910
This is an early tube with lime sample from the late 19th century. The mineral is Fluorescent and Phosphorescent.
Early maltese cross tube
This tube is made late 19th century with platinum wire connections and blue glass electrode sealings.
The tube is filled with fluorescent and phosphorescent willemite minerals which glow very bright apple green.
Afterglow of the minerals
A similar mineral filled tube is displayed in the French 1869 Physics book from Dechanel.
Sir William Crookes
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List of Crookes tubes sold by Queen & Co 1888 after the
Notice the missing of No.3 which is a mineral tube like No.4 containing a diamond which fluoresced bright green. These kind of expensive mineral tubes were only made on special order. No.20 is the same tube as No.19. No.10 same as No.9.
demonstration of William Crookes in Sheffield in 1879.
The numbers in the catalogues corresponding to the figure drawings in the lecture.
5 mineral Crookes tube.
Probably Pressler ca 1920
These tubes were made in several sizes, this is the smallest sold. Height 27cm
Fluorescent and phosphorescent minerals
A rare Crookes tube with a large synthetic ruby sample. Produced by Emil Gundelach or Müller-Uri ca 1910
The development of crystal growth technology for synthetic ruby or corundum was done by the French chemist Auguste Verneuil in 1902 and was published in 1904.
made by Pressler ca 1935
Small tube filled with coral samples ca1930 height 16cm
Mineral samples light up influenced by cathode rays.
Coral and mineral samples light up influenced by cathode rays.