“Invented by Nathan Stubblefield in 1908, the device came complete with an
unwieldy metal transmitter.

A far cry from the tiny mobile phones in use today, the telephone was made up
of a system of wire suspended between metal rods with the transmitter placed
on a train carriage or boat.

When the vehicle neared, a signal was sent through the air to the telephone
using magnetic fields. It could be heard near the other end of the wire
through another phone.”

(Photos of just how big this thing actually was are included in the link.)
http://www.telegraph.co.uk/news/uknews/1947168/’Mobile’-phone-enjoys-centenery.html