Why did John Smeaton give the Eddystone Lighthouse a curved and tapered shape?

John Smeaton designed the third Eddystone Lighthouse with a curved and tapered profile to enhance the structure's stability and durability against the sea.

Because the tower relied primarily on its own weight for stability, it required a wider base that tapered toward the top. Smeaton chose a curved profile rather than a straight conical taper for two primary reasons:

• Energy Dissipation: The curve helped dissipate the force of wave impacts by directing the waves to sweep up the walls rather than striking the structure with full force.1
• Aesthetics: The curved shape was considered visually attractive.1

To further ensure the tower could withstand the pounding of the waves, Smeaton utilized dovetailed masonry blocks, a technique that became a standard for wave-swept structures.21