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Discharge Tubes


This is a flat cardboard box containing a number of mixed glass discharge tubes. There are 27 intact tubes in the box, and some miscellaneous pieces of broken glass, possibly associated with a a half tube, broken at the narrow point. Each intact tube consists of a cylindrical tube narrower in the middle than at both ends, with a metal electrode that extends inside the wider glass tube fixed on each end. These are of varying sizes; some have small paper labels giving some details about the gaseous contents. All of these are nestled in a layer of fluffy cotton-like material and covered in a piece of scrap corrugated cardboard.

The gases that these tubes contain are: Oxygen, Nitrogen, Selenium, Iodine (broken), Hydrogen (?).

Accession Number: 2018.ast.84 (DAA-0031)

Alternative Name: Gas-filled tubes

Primary Materials:

Glass, Textiles: Cotton?, Metal: Iron Alloy, Cardboard


Some of the glass tubes have small paper stickers stuck on them. Some of these are printed with: “RICH. MULLER-URI

These labels have things written on them, such as: “O 300mm” “100mm O” “H4” “N 760mm”.

Written in crayon on the piece of cardboard: “Discharge Tubes Very Fragile”

Stamped on the box: “Madame Senior

Handwritten on the top of the box in red crayon: “Discharge Tubes Very Fragile”

Dimensions (cm):

Box: Length = 38.3, Width = 25.5, Height = 5.7, Longest Tube: Length = 23.5, Diameter = 2


Discharge tubes are filled with gases which, when a current is run through the tube, produces a visible discharge. These tubes may have been used for producing distinctive element lines for calibrating a spectrometer.


Fair: The cardboard box and cardboard cover have been reused. They are very worn and dirty over the surface but intact, without significant tears or damage.

All of the gas-discharge tubes show varying levels of use. Some are broken, likely while they were in the box. Some are blackened or discoloured towards the electrode ends or throughout the length of the tube. Many of the metallic contacts at each end appear to have be resealed or otherwise mended; these all show signs of corrosion over the surface. The labels on the tubes are dirty and in some cases stained or browned (perhaps through exposure to heat).

Associated Instruments:

Manufacturer: Most tubes: Richard Müller-Uri

Date of Manufacture: 1920s


This object was likely moved from the David Dunlap Observatory in Richmond Hill in 2008, upon the sale of the observatory. It was stored at the Department of Astronomy and Astrophysics until 2017, when it was moved to a new storage location in McLennan Physical Laboratories.

Additional Information and References:

Historical Notes: