Sandbanks are ahazard to marine traffic.
Mitchell decided to do something about it despite having no formal training in engineering, or lighthouse building.
Remarkably, Alexander Mitchell was also blind.
Alexanders eyesight had always been poor, but it became progressively worse as he became older.
At age sixteen, he could no longer read.
His family helped him in his studies as young Alexanders world slowly spiraled into eternal darkness.
At twenty-two, he went completely blind.
By some accounts, Alexanders loss of eyesight was due to a childhoodinfection of smallpox.
Despite his disability Mitchell was an outgoing and optimistic man.
He married a neighbours daughter, against the wishes of his mother, and together they had five children.
He acted so naturally in the presence of others that some peopledidnt even knowhe was blind.
Early next morning, he returned to find it still firmly fixed in position.
After a second successful trial of his invention, he went to London and had the screw pile patented.
This was quickly followed by another lighthouse at Morecambe Bay in 1839.
Mitchell personally supervised the construction of several, travelling to the site where they were being erected.
He would be seen climbing ladders and scaffolding on half-built lighthouse, oblivious to the dangers.
At times, he would fall into the sea, but come up again cool and collected.
Most industries use screw pile foundations due to the cost efficiencies and reduced environmental impact.
He died at the age of 88 at his home near Belfast in 1868.
Model of the Maplin lighthouse atLondons Science Museum.
Seven Foot Knoll Lighthouse in the Chesapeake Bay, Maryland, was another screw pile lighthouse.
The lighthouse was decommissioned in 1997 and transferred to the Baltimore Maritime Museum where it stands today.
Middle Bay Lighthouse is screw-pile lighthouse.
The structure is located offshore from Mobile, Alabama, in the center of Mobile Bay.
Photo credit:Harley Flowers/Flickr
