Mathematical Bridge

William Etheridge was one of a very long family line of carpenters called variously Edrich, Edriche, Eteridge, or Etheridge from Stradbroke and Fressingfield in Suffolk. His birth is not recorded, but his baptism took place on 3rd January 1708/09 at St Margaret’s parish church, South Elmham, about 5 miles north-east of Fressingfield. His career as a master carpenter first comes to light in 1738–49 when he worked under James King in the building of the first bridge to cross the Thames at Westminster, first as King’s foreman, then replacing him after King’s death in 1744. He was credited as the inventor of a battering ram to assist in the striking of the centres, and an underwater saw to cut off piles underwater. From 1747–50 he worked on the Walton Bridge, and in 1748 produced the design and model for the Queens’ bridge. From 1751–56 he worked as surveyor for the construction of Ramsgate Harbour in Kent. In 1761 he was consulted on the state of St Olave’s bridge at Herringfleet, Suffolk. He died aged 67 on 3rd October 1776 in Westminster and was buried on 15th October 1776 at Fressingfield.