Heating Effects Tube (early 1900s) |
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This type of tube was created in the late 1800s by William Crookes to demonstrate the significant amount of energy carried by the cathode rays (electrons) that stream from the cathode to the anode. The magnitude of the energy was indicated by the fact that the platinum foil in the center of the tube glowed red when a high voltage was applied. |
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| To enhance the heating effect, Crookes used a cup-shaped cathode which focused the cathode rays on the platinum target - the electrons leave the cathode at right angles to its surface. Later, in 1896, Herbert Jackson was the first to use this type of cathode for the production of x-rays. The example on display is hard to date because this type of tube is commonly used in classroom demonstrations and has been in continuous manufacture since the 1800s | |
