Lightning Protector

Nikola Tesla's lightning protector, patented in 1918 under U.S. Patent 1,266,175, challenged conventional pointed rods by using a smooth, ellipsoidal or cupola-shaped terminal with large radii of curvature to prevent strikes altogether. Sharp points, per Tesla, concentrated charge and promoted ionization, inviting discharges; his design dispersed charge evenly, preserving air's insulating properties and minimizing leakage. Connected to a low-inductance grounded conductor, it elevated the terminal for broad protection while avoiding streamer formation.

Drawing from high-voltage experiments and natural phenomena observations, Tesla aimed for proactive defense, critiquing Franklin rods as flawed. Though unadopted widely, it anticipated modern prevention systems emphasizing dissipation over attraction. Contemporary early streamer emission terminals and charge transfer concepts echo his ideas, influencing surge protection and structural safety in thunderstorm-prone areas.