CHAPTER IV

FARADAY AND THE FIRST DYNAMO

Count Rumford.--Count Rumford's experiment with the cannon.--Davy.--Faraday's electrical discoveries.--Oersted and electromagnetism.--Ampère.--Arago.--Faraday's first electric motor.--An electric current produced by a magnet.--Detecting and measuring an electric current.--An electric current produced by the magnetic field of another current.--Faraday's dynamo.--A wonderful law of nature