history of antenna
IT is not surprising thawt ire antennas were inaugurated
in 1842 by the inventor of wire telegraphy, Joseph
Henry, Professor of Natural Philosophy at Princeton,
NJ. By ¡°throwing a spark¡± to a circuit of wire in an
upper room, Henry found that the current received in a
parallel circuit in a cellar 30 ft below could magnetize needles.
With a vertical wire fromh is study to the roof of his house, he
detected lightning flashes 7-8 mi distant. Henrya lso sparked
to a telegraph wire running from his laboratory to his house,
and magnetized needles in a coil attached to a parallel wire
220 ft away. Later experiments may have extended the range
to half a mile.