At the west end of the nave of Westminster Abbey is a black and white marble monument to John Conduitt, politician and Master of the Mint. It includes a large gilt brass medallion portrait and a shield of arms, showing the coats of arms of Conduitt and Barton. Around the portrait are the words "John Conduitt Master of the Royal Mint" in Latin. A sarcophagus is supported on lion-paws. On the pediment of this a memorial inscription was inserted for Jeremiah Horrocks, astronomer. The monument was reduced and elements re-arranged in the 19th century, probably when the monument to William Pitt the Younger was erected and the present canopied niche was made. The sculptor was Sir Henry Cheere.
He was buried on the right hand side of Sir Isaac Newton at the other end of the nave and his monument faces that of Newton. The Latin inscription can be translated:
John Conduitt Esq. wished his remains to be placed opposite this spot, near to the ashes of the great Newton, to whom he was linked by ties of affinity. Because of the sweetness of his presence, the honesty of his character, the pleasantness of his disposition, and, that virtue in which above all others he excelled, his philanthropy, as lately he was the delight of his friends, so now he is the cause of their very great grief and sense of loss. He took to wife Catherine Barton, a most excellent woman, by whom he had one daughter, named after his wife. This monument, destined by the most sorrowful widow for her dearest husband, was ordered to be dedicated to the memory of both parents, so richly deserving of her, by their surviving daughter, wife of the Hon. John Wallop, eldest son of the Rt. Hon. John, Viscount Lymington. He died on 23rd May 1737 aged 49, she on 20th January 1739, aged 59.
John was born in Hampshire, son of Leonard and Sarah Conduitt and baptised in London on 8th March 1688. He was educated at Westminster School and Cambridge university. In 1711 he was judge advocate in Portugal with the British forces and was a captain of dragoons. He married Catherine, niece of Sir Isaac Newton, in 1717 and their daughter Catherine became Viscountess Lymington when her husband John succeeded to the title. Politician and author Conduitt succeeded Newton as Master of the Mint and preserved many of his personal papers. His work Observations on the present state of our gold and silver coins was much praised. His wife was buried with him and their daughter buried with her parents on 4th May 1750.