Alexander Mitchell, Irish engineer, invented the Screw-pile lighthouse (died 1868)

Alexander Mitchell was an Irish engineer who from 1802 was blind. He is known as the inventor of the screw-pile lighthouse.

A screw-pile lighthouse is a lighthouse which stands on piles that are screwed into sandy or muddy sea or river bottoms. The first screw-pile lighthouse to begin construction was built by the blind Irish engineer Alexander Mitchell. Construction began in 1838 at the mouth of the Thames and was known as the Maplin Sands lighthouse, and first lit in 1841. However, though its construction began later, the Wyre Light in Fleetwood, Lancashire, was the first to be lit.