John Appold

John George Appold (1800 to 1865) was a British engineer and inventor who earned his living as a fur skin dyer, a trade he inherited from his father and improved with scientific methods. Born on 14 April 1800, he showed an early talent for calculation and mechanical work. He is best remembered for the Appold centrifugal rotary pump, a prominent exhibit at the International Exhibitions of 1851 and 1862, and for the paying-out apparatus used in early attempts to lay the submarine telegraph cable to America. Fellow engineers valued his gift for tracing the causes of faults in machines and for adapting existing contrivances to new needs; when the outfall works at the St Germains Sluice were blown up, he suggested syphons to carry off the upland water of the fen country. He also devised instruments such as a delicate thermometer and a hydrometer for damping air to a set degree of moisture, and filled his own home with automatic devices. He was elected a Fellow of the Royal Society in 1853 and died at Clifton on 31 August 1865.