Geissler Tube

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Geissler Tube




Physical Description

This Geissler tube is approximately 155 centimeters long and weighs 984.4 grams or about 2.17 pounds. The outer tube is made up of symmetric sections of long tubes with a large bulb at the center. These sections themselves contain smaller sections of various tubes and bulbs. These smaller sections hold the conducting fluids and rare gases that when electrified create different colors of light. These smaller sections of glass tubing were made to be attention grabbing with swirling, spiraling and zig-zagging shapes.

Condition: Damaged, electrical damage that blackened one side and knocked the platinum electrodes loose. The instrument may possibly work with a tesla field.  This Geissler tube is missing the small wires that should extend from both ends to allow it to be hooked up to a power source.

Functional Use

A Geissler tube is a gas discharge tube that lights up or fluoresces when a current is applied to the electrodes at either end of the tube. Geissler tubes were a novelty used for entertainment, but could also be used for demonstrations in classes like physics or chemistry. They were also used as high voltage indicators because they light up without contact when brought near a high voltage alternating current. Unfortunately this Geissler tube has a broken electrode on one end and is inoperable.  To use the Geissler tube, the user must apply high voltage across the electrodes on each end of the glass tube. When a current is applied and flows through the tube, an electrical field is created between the two electrodes. In general, any free electrons in an electrical field will accelerate from the negative electrode towards the positive electrode. The electrons in the tube accelerating from the negative electrode to the positive electrode, will collide with the gas molecules in the tube. This collision may cause the electrons to give some of their energy to the gas molecules they are colliding with causing the gas molecules jump to a higher energy or excited state. The gas molecules do not stay in their excited state, instead they get rid of their excess energy by emitting their excess energy as light. The energy that is emitted is equal to the difference in energy between the gas molecule’s normal state and excited state. This energy determines which color of light will be emitted. The energy of the light is inversely related to the wavelength of the light and the wavelength of the light emitted is associated with a certain color of light. For example, Mercury vapor (Hg) can emit purple, blue, green or yellow color lights depending on how big the energy gap is between its excited and normal state. If the energy gap, and therefore the energy emitted is very large, Mercury will emit a purple light which has a shorter wavelength. Conversely if the energy emitted is smaller, Mercury will emit a green or yellow light which both have longer wavelengths. Although they have used almost all kinds of gasses in experimentation, Noble gasses such as Argon and Neon were favored for Geissler tubes as they are easier gasses to excite and produced a greater spectra (glowing light).  Different gases have specific colors of light they can emit and so the color that the Geissler tube lights up depends on the gas inside of it.


Elisha Earley, TJ Johnston, Nick Littlefield, John Medley, and Anna Polk


Procured around the 1960's. Purchased back when Michigan Tech was transitioning names from Michigan College of Mining and Technology (MCMT) to Michigan Technological University (MTU)




Physical Object


No accession number


United States

Physical Dimensions

*Referring to the front of the box being the locking side and the measurements being inturpreted from left to right*

Tube Dimensions: 155 cm Long.  Diameters of outermost  feature of glass from leftmost to right: 33.15mm 53.54mm 34.01mm Bulb - 29.8cm circumference 33.64mm 51.80mm 33.43mm Tube Mass 984.4 grams

Box dimensions: 162.5cm Length x 14.5cm Height x 15.2cm Width. Box wall thickness at 1cm and holding blocks thickness at 2cm. Distance between holding blocks 138.5cm. Height of holding blocks 17.8cm *Referring to the front of the box being the locking side and the blocks being numbered from left to right. Distance between storage blocks 1 and 2 is 61.3cm. Distance between storage blocks 2 and 3 is 83.3cm. Distance between locks 1 and 2 is 61.8cm. Distance between locks 2 and 3 is 60.3cm. Glass sections Width - 9.2cm Length - 48.7cm

Random items: Traces of excelsior (shredded fluffy wood) which was possibly used to ship the item.
String attached to storage block 2 Bottom of box is unfinished Strange piece of wood found in the box


Tube: Primarily glass filled with a currently unknown gas, as well as a unknown liquid. Two electrodes made of a currently unidentifiable metal, but however thought to be platinum coated. (Contents are all inside glass tubes and cannot be physically tested without destroying the instrument)

Box: Wood, glass, felt, and brass


Cenco - Central Scientific Company, Chicago Illinois


Inventory numbers on box: 0066 or 9900 | 74500

Included Slip:   Inventory Numbers on slip: 5700 | 74500
"Description:  Cenco Gleisser Tube for demonstrating the ionization of a gas under a the influence of a high potential.  155cm long. (An irreplaceable eleaborate piece of glass blowing.)"

Rec'd       HH      Cost    $200   
The cost was crossed out with the word void above it (See  photo)

History of the Object

This Geissler tube was made by Cenco in Chicago IL. It is undated, however due to a purchase slip for the piece containing both MTU and MCMT (standing for Michigan Technological University and Michigan College of Mining and Technology, respectively) it was likely purchased in the 1960s, around the time Michigan Tech changed its name for the final time. Cenco or Central Scientific Company was created in 1900 out of the former Olmstad Scientific Company which was destroyed in a fire. Cenco sold scientific education equipment through a mail order catalogue.
Age - 40+ years old purchased back when MTU had the name MCMT, bought for $200 adjusted for inflation about $1600 today.


Physics Department


Greenslade, Jr. Thomas B. "Geissler Tubes." Geissler Tubes. Accessed March 22, 2017.

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Elisha Earley, TJ Johnston, Nick Littlefield, John Medley, and Anna Polk, “Geissler Tube,” Michigan Tech Inventory of Historic Scientific Instruments, accessed May 7, 2021,