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a lightning conductor,
a lightning arrester, or
a lightning discharger.
However, these terms actually refer to lightning protection systems in general or specific components within them.

Lightning rod dissipators make a structure less attractive by which charges can flow to the air around it. This then reduces the voltage between the point and the storm cloud, making a strike less likely. The most common charge dissipators appear as slightly-blunted metal spikes sticking out in all directions from a metal ball. These are mounted on short metal arms at the very top of a radio antenna or tower, the area by far most likely to be struck. These devices reduce, but do not eliminate, the risk of lightning strikes.

Arrestors
A lightning arrestor is a device that shunts or diverts the massive voltage and electrical current of a lightning strike to an earthed ground. Electrical equipment can be protected from lightning by an arrester, a device that contains one or more gas-filled spark gaps between the equipment's cables and earth. An arrester is designed to handle much higher jolts of electricity than a surge protector, which cannot handle a direct strike at all.
Should lightning strike a building, the current will travel through the conductor rather than through the fabric of the building, causing less damage. Should lightning strike one of the cables, the high voltage will cause the gas in the spark gap to break down and become a conductor, providing a path for the lightning to reach the ground without passing through the equipment. It typically involves a spark gap, across which a normal voltage cannot arc.
When lightning exceeds the arrestor's breakdown voltage, the currents arcs to the ground and prevents arcing around inside sensitive electronic equipment connected further downline. The spark gap may be filled with a noble gas, or with air. Other types may work by blocking normal alternating current (AC), but allowing the direct current (DC) from a lightning discharge.
Lightning arrestors are typically installed on electric power transmission lines, and on radio tower feedlines between the radio antenna and transmitter. Smaller ones can also be installed on the mains electricity service coming into a building (even a home), just before the circuit breaker panel. Telephone wires also have fusible links sometimes where they enter a building, connected by carbon which will vaporize with very high current.

History
Lightning damage has been with humanity since we started building structures. Early structures made of wood and stone tended to be short and in valleys and as a result lightning hit rarely. As buildings became taller lightning became a significant threat. Lightning can damage structures made of most materials (masonry, wood, concrete and even steel) as the huge currents involved can heat materials, and especially water to high temperatures causing fire, loss of strength and explosions from superheated steam and air.

Europe
The church tower of many European cities, usually the highest structure, was the building often hit by lightning. Early on, Christian churches tried to prevent the occurrence of the damaging effects of lightning by prayers. Priests prayed,

temper the destruction of hail and cyclones and the force of tempests and lightning; check hostile thunders and great winds; and cast down the spirits of storms and the powers of the air.
Peter Ahlwardts ("Reasonable and Theological Considerations about Thunder and Lightning", 1745) gave information to individuals seeking cover from lightning to go anywhere except in or around a church.[3]

United States
In the United States, the pointed lightning rod conductor, and more accurately the "lightning attractor", was invented by Benjamin Franklin as part of his groundbreaking explorations of electricity. Franklin speculated that, with an iron rod sharpened to a point at the end,

the electrical fire would, I think, be drawn out of a cloud silently, before it could come near enough to strike.
Franklin had speculated about lightning rods for several years before his reported kite experiment.

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