Word: magnetism
(lookup in dictionary)
(lookup stats)
Dates: during 1890-1899
Sort By: most recent first
(reverse)
...present shape was in 1876, when a very simple apparatus, which could transmit a few words and phrases, was placed on exhibition at the Centennial Exhibition by its inventor, Mr. Alexander Graham Bell. The first form was what is known as the magneto telephone, which consisted of an electro magnet at each end of the line in front of which were placed armatures. When one of these armatures was vibrated the same vibrations were observed in the other. Mr. Bell then found that by means of a small diaphragm he could transmit the sound waves made by the voice...
...speaker said in substance: Although we can only conjecture what electricity is we are practically interested in what it does. The principle of the dynamo is that a continuous wire revolving under the influence of a magnet has electrical currents induced in it, and this induced current is sent out to do work...