![]() The idea was that glass objects, being non-conductors, are seldom struck by lightning. If after a storm a ball is discovered missing or broken, the property owner should then check the building, rod, and grounding wire for damage.īalls of solid glass occasionally were used in a method purported to prevent lightning strikes to ships and other objects. The main purpose of these balls, however, is to provide evidence of a lightning strike by shattering or falling off. The ornamental appeal of these glass balls has been used in weather vanes. ![]() Lightning rods were embellished with ornamental glass balls (now prized by collectors). In the 19th century, the lightning rod became a decorative motif. Louis Post-Dispatch of October 21, 1906, with a traveling salesman selling lightning rods ĭrawing of a general store by Marguerite Martyn in the St. Franklin speculated that, with an iron rod sharpened to a point, "The electrical fire would, I think, be drawn out of a cloud silently, before it could come near enough to strike." Franklin speculated about lightning rods for several years before his reported kite experiment. Although not the first to suggest a correlation between electricity and lightning, Franklin was the first to propose a workable system for testing his hypothesis. ![]() In what later became the United States, the pointed lightning rod conductor, also called a lightning attractor or Franklin rod, was invented by Benjamin Franklin in 1752 as part of his groundbreaking exploration of electricity. After local protests, Diviš had to cease his weather experiments around 1760. The apparatus was, however, mounted on a free-standing pole and probably better grounded than Franklin's lightning rods at that time, so it served the purpose of a lightning rod. Diviš's apparatus was, according to his private theories, aimed towards preventing thunderstorms altogether by constantly depriving the air of its superfluous electricity. There is an ongoing debate over whether a "metereological machine", invented by Premonstratensian priest Prokop Diviš and erected in Přímětice (now part of Znojmo), Moravia (now the Czech Republic) in June 1754, does count as an individual invention of the lightning rod. Peter Ahlwardts ("Reasonable and Theological Considerations about Thunder and Lightning", 1745) advised individuals seeking cover from lightning to go anywhere except in or around a church. The church tower of many European cities, which was usually the highest structure in the city, was likely to be hit by lightning. However, the true intent behind the metal rooftop and rebars remains unknown. The Nevyansk Tower was built 28 years before Benjamin Franklin's experiment and scientific explanation. The Nevyansk Tower was built between 17, on the orders of industrialist Akinfiy Demidov. This lightning rod is grounded through the rebar carcass, which pierces the entire building. The spire of the tower is crowned with a metallic rod in the shape of a gilded sphere with spikes. The heat causes a potential for structure fire, and its rapidity can lead to explosive damage as well.Ī lightning conductor may have been intentionally used in the Leaning Tower of Nevyansk. ![]() Lightning can damage structures made of most materials, such as masonry, wood, concrete, and steel, because the huge currents and voltages involved can heat materials to high temperature. Copper lightning rod at the Tesla Science Center, based on a Hemingray insulatorĪs buildings become taller, lightning becomes more of a threat. The principle of the lightning rod was first detailed by Benjamin Franklin in Pennsylvania in 1749, who in subsequent years developed his invention for household application (published in 1753) and made further improvements towards a reliable system around 1760. Copper and its alloys are the most common materials used in lightning protection. ![]() The main attribute common to all lightning rods is that they are all made of conductive materials, such as copper and aluminum. Lightning rods come in many different forms, including hollow, solid, pointed, rounded, flat strips, or even bristle brush-like. The lightning rod requires a connection to the earth to perform its protective function. In a lightning protection system, a lightning rod is a single component of the system. Lightning rods are also called finials, air terminals, or strike termination devices. If lightning hits the structure, it will preferentially strike the rod and be conducted to ground through a wire, instead of passing through the structure, where it could start a fire or cause electrocution. Lightning striking the lightning rod of the CN Tower in Toronto, Canada.Ī lightning rod or lightning conductor ( British English) is a metal rod mounted on a structure and intended to protect the structure from a lightning strike. ![]()
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |