This paper describes an investigation into the wear of gold coinage which was initiated in 1798. The initial approach was to investigate the physical properties of 13 alloys of gold, each of which contained 2 carats of another element. Experiments with a specially constructed wear-testing machine were carried out in which both coins and coin blanks of the same and different metals were rubbed on one another. The conclusions of the work were that the 22 carat gold alloy then in use should not be changed. -- AATA