Smeaton's Tower administrator Sir John Barrow. Smeaton's Tower has been a Grade I-listed building since 1954. It is open for visitors, who may climb 93 steps, including steep ladders, to the lantern room, and observe Plymouth Sound and the city. Smeaton's Tower Smeaton's Tower is a memorial to celebrated civil engineer John Smeaton, designer of the third and most notable Eddystone Lighthouse. A major step forward in lighthouse design, Smeaton's structure was in use from 1759 to 1877, until erosion of the ledge it was built upon forced new construction. The tower was largely dismantled and rebuilt on Plymouth Hoe in Plymouth,
John Smeaton Wright brothers determined with wind tunnels that the Smeaton coefficient value of 0.005 was incorrect and should have been 0.0033. In modern analysis, the lift coefficient is normalised by the dynamic pressure instead of the Smeaton coefficient. Smeaton is important in the history, rediscovery of, and development of modern cement, identifying the compositional requirements needed to obtain "hydraulicity" in lime; work which led ultimately to the invention of Portland cement. Portland cement led to the re-emergence of concrete as a modern building material, largely due to Smeaton's influence. Recommended by the Royal Society, Smeaton designed the third Eddystone Lighthouse (1755–59).