This is a question about old physics lab equipment.

This and this question led to the question in SciFi SE Crookes Radiometer at the end of a telescope in old movie scene, something about a comet? which led to the image below.

Of course one does not use wires to couple a radiometer to a telescope.

However, my question is about the (now old, possibly then as well) Crookes Radiometer shown in the image from 1965. There are two terminals in the wooden base of the radiometer.

Question: Did old Crookes Radiometers ever have a pair of terminals? I can imagine a heater used to evaporate trace amounts of some material to adjust the pressure for teaching/demonstration purposes, or even some kind of getter pump to reduce the pressure (as some electron tubes had), but I thought I'd ask here to see if someone familliar with older lab equipment might know.

below: Screen shot from this video of Episode 3 (1965) of The Time Tunnel The end of the World after roughly 36:15.

enter image description here

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    $\begingroup$ I'm looking for a tag like equipment or apparatus or something like identify-this-object but so far no luck. $\endgroup$
    – uhoh
    Commented Mar 13, 2019 at 10:55
  • $\begingroup$ I originally asked this question in Physics SE ten months ago but there was no activity. Today I've deleted it there and posted it here instead, since migration is no longer possible. $\endgroup$
    – uhoh
    Commented Mar 13, 2019 at 10:56
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    $\begingroup$ Crookes' Crookes Radiometer had terminals, but not like your image. $\endgroup$ Commented Mar 25, 2019 at 3:12
  • $\begingroup$ @KeithMcClary I'd never seen that before, thank you! Isn't it totally amazing coincidence that Crookes' Radiometer was a Crookes Radiometer!? ;-) $\endgroup$
    – uhoh
    Commented Mar 25, 2019 at 5:08

1 Answer 1


Google is your friend here. I found a forum which contained a reference to this image

which shows a barely-working generator. Exerpt from that image:

induction generator

The forums I found generally suggested that it's pretty much impossible to get enough torque to drive any mechanically connected generator system. So it can be done but I suspect the image you provided is a case of "Let's toss in as much cool-looking lab toys as we can."

  • $\begingroup$ Your answer to "Did old Crookes Radiometers ever have a pair of terminals?" is Yes, or No? Generator or torque seems incredibly specific thing to negate, and doesn't really rule out other uses. And that isn't an "old Crookes Radiometer" either. $\endgroup$
    – uhoh
    Commented Mar 13, 2019 at 13:50
  • $\begingroup$ @uhoh please explain what a pair of wires would otherwise do. Light a bulb underneath the mechanism? $\endgroup$ Commented Mar 13, 2019 at 17:28
  • $\begingroup$ Re-read the question for two possible examples I've listed just to get the ball rolling. Anyway the question explains that the photo is circa 1965, so then or earlier is the timeframe to look at. $\endgroup$
    – uhoh
    Commented Mar 13, 2019 at 17:55

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