What Is a Lightning Rod and How Does It Work?

If lightning strikes a building, the electricity can cause a fire or can electrocute anyone who is nearby. But how can people protect themselves against one of the strongest and most unpredictable forces of nature? A lightning rod, also called a finial or air terminal, is a simple device that can protect all sorts of structures from electrical damage during a storm.

What Is It?

A finial is a metal rod that is mounted on top of a building or any other structure that needs to be protected from lightning, including bridges and ships. They can come in many forms besides just straight rods, including rounded, pointed, or flat. They may be hollow or solid, and can even be made up of bristles, similar to a brush. Whatever form they come in, the metal spikes draw the electrical charge from a lightning strike, diverting the energy by transferring it to the ground through a wire connected to the device.

How Does It Work?

A simple lightning rod depends on three integral pieces – the metal rod, a wire, and a grounded absorber. When the finial is struck, the electricity naturally travels along the conductive wire, which is made up of a conductive material, and into a ground. The ground, also called an earth, is another piece of metal that is driven into the actual ground. From here the electricity disperses without causing damage to the structure. However, if homeowners suspect that their rod has been hit, they should still be sure to examine their home for any damage since a great deal of energy has been transferred.

Buildings that need extra protection may use a system made up of several of these devices that have been networked together through bonding conductors, connectors, and supports. The conductors are then connected to the ground in the most direct path, ensuring that the electricity is sent away from the building as quickly as possible.

History of the Lightning Rod

Benjamin Franklin, the United States’ pioneer of electricity, designed the earliest lightning rod. He first came up with the concept in 1749, and over the next decade, he developed the idea into a usable household product. In fact, early incarnations of this device were known as a Franklin rod. There is some evidence that the first lightning rod was used on a tower in Russia in the early 18th century, before Benjamin Franklin’s invention, but there is no concrete proof that this was the intention of the design.

After the use of the finial had become common, people in the 19th Century began to use them as decorative accents for homes. They were often decorated with glass balls, which were both attractive and served to alert occupants that a strike had occurred, as the balls would shatter when hit.

Thanks to this ingenious device, people can now rest comfortably during an electrical storm and enjoy the awesome display of nature’s power without worrying that they are in danger.