Scull (the same word as "skull," cf. Swed. sized, basin, hufvud-sk&l, skull of the head), a light oar with blade more concave than the ordinary racing oar and with shorter helm, thus allowing the user to hold one in each hand. "Sculling" is therefore the propulsion of a boat by one person with a pair of sculls. The word is also applied to the propulsion of a boat by one scull worked over the stern, the blade being swept through the water from side to side, turning diagonally at each stroke; the sculler usually stands. The principles of sculling with a pair of sculls are the same as those of rowing. For the type of boat used in racing see Boat. The Wingfield Sculls, a race which forms the English Amateur championship, was instituted in 1830. It is rowed from Putney to Mortlake. The Diamond Challenge Sculls, instituted in 1844, are rowed for at Henley Regatta. The earliest professional championship sculling race was rowed on the Thames in 1831. Since 1876, when an Australian (E. Trickett, of Sydney) beat J. H. Sadler, the professional championship of the world has been held by Australians or Canadians; the principal champions have been E. Hanlan (Toronto), 1880-1884, W. Beach (New South Wales), 1884-1887; other names are H. E. Searle, J. Stanbury, G. Towns and R. Arnst (New Zealand). Most of the races have been rowed on the Paramatta river. In August 1910 the race was rowed on the Zambezi between E. Barry of England and Arnst, the latter winning.