[thedoc (OP)]

This is a beautiful little demonstration dating back to to Lord Kelvin. Using a few cans wires and dripping water it is possible to generate thousands of volts in a beautifully elegant piece of physics.

 Read more about this experiment.


Garage science is a blog of science experiments you probably can't or shouldn't do at home

 

[Bored chemist]

Shouldn't the top two containers be connected together too?

[rosy]

Yeah. And infact they are. Both are sitting (as far as I recall) on a sheet of aluminium which you might just be able to see looking at the set-up in the photo, forming the connection (the paint having been sanded off the bottom of the pots). You could equally use a single trough of water with two taps out of it. An extra wire ought to be drawn in...

[daveshorts]

You are of course right, I have now updated the diagrams

[Mick]

"Electrons in the water are attracted by the positive ring, so the drops which are just forming in this ring become negative and then fall into the pot below. "
If the positive ring is attracting electrons from the water, shouldn't that leave the water drops with a positive charge? Or are we looking at ionization of the air within the ring (positive ions sucking electrons from the water)?

[Mick]

...no that wouldn't work either -- dammit!

[Josh]

Scuse me,
Is there a way to harness this 1000v energy?

[Samuel Moon]

I want to know how we can measure the voltage in this equipment(Kelvin's water dropper)

[Calum]

I think it is important to mention that the effect is due to Electrostatic Induction ( see http://en.wikipedia.org/wiki/Electrostatic_induction ).

[Adrian]

Hello i was wondering why my Klevin Water dropper is not working. I have practically copied the model in the video except my drippers are 50ml glass burets (large pippets) and i have a wire attaching these together  they then drip down through my inducers (coat hanger wire) to my collectors which are baked bean tins with an alumnium false bottom which  i added due to the plastic lining on the inside of the cans also i have done the experiment in the souther hemisphere with aproxx 60% or less humidity and i dont know if its my flow rate thats the promblem or what also i checked for shorting with an am radio but there wrre none also i was aproxx getting 1.5 dropps per second
thanks if any one has a solution please contact me on aj_wild@msn.com

[Michael (Tasmania)]

The water holding containers and droppers can be made from electrically insulating materials and not connected to earth provided there is a water path connecting them allowing ions to flow from one dropper to the other as in a variant I have made.