Who invented the Weight-For-Age scale?

Who invented the Weight-For-Age scale?  As the name suggests, the Weight-For-Age (WFA) scale is a sliding scale of weight allowances that younger horses receive from older, mature horses over different distances at various stages throughout the season. As the season progresses, younger horses, especially three-year-olds, mature physically and are better able to compete with their elders, so the weight allowance decreases every two weeks until the end of the year.

The WFA scale has been revised several times in its history, but is essentially the same as it has always been. It was invented, or at least formalised, by Admiral Henry John Rous, who served in the Royal Navy in the Napoleonic War in the early nineteenth century, but became senior steward of the Jockey Club in 1838. It was in that capacity that he published ‘The Laws and Practices of Horse Racing’ in 1850 and devised the WFA scale in 1851. Rous was was appointed official Jockey Club handicapper in 1855, earning the derogatory title of ‘Dictator of the Turf’. He is, however, commemorated by the Listed Rous Stakes, which is run over five furlongs at Ascot each October.