January 12th in 1832 Michael Faraday did the following experiment in London:

He placed two copperplates in the Thames river at opposite ends of a bridge crossing at 300m apart. He then connected these copperplates with insulated wires to a voltage meter.
He measured a 19mV voltage. Magnetic field in London is measured to be 43µT (43*10^-6 T) and inclination is 71 degrees.

Why did Faraday's meter measure a voltage and what was the velocity of the water in the river Thames at that time?

In a static state, do the cations and anions normally exist? ie as in a glass of water.

I understand that lightning is generated by the friction of warm air rising against a cold front.

Is something like that going on here? Friction of the faster midstream current being impeded by slower currents at the banks?

I can understand that the magnetic field might induce a migration of charged particles, but would that be the same if the location of the plates was rotated 90 degrees?

Posted by brianjn on 2006-10-20 22:27:26