Quad (figure skating)
A quad, or quadruple, is a figure skating jump with at least three but less than four revolutions. Most quadruple jumps have 3 1/2 revolutions; the quadruple Axel has 4 1/2 revolutions, although no figure skater to date has completed this jump in competition. The quadruple toe loop and quadruple Salchow are the two most commonly skated in the discipline. Quadruple jumps have become increasingly common among World and Olympic level men's single skaters, to the point that not having one in a program has come to be seen as a severe handicap. The first person to land a ratified quadruple jump in competition was Canadian Kurt Browning in 1988. In 2002, Miki Ando became the first woman to do so, and she remains one of only two women to have landed a ratified quadruple jump in competition.
Edward Turner
By now, living at various addresses in Peckham and East Dulwich, in the London Borough of Southwark and running Chepstow Motors, a Peckham Road motorcycle shop with a Velocette agency, Turner conceived the Square Four engine in 1928. At this time he was looking for work, showing drawings of his engine design to motorcycle manufacturers. The engine was essentially a pair of 'across frame' OHC parallel twins joined by their geared central flywheels, with a one-piece four-cylinder block (or Monobloc) and single head. The idea for the engine was rejected by BSA, but adopted by Ariel. Thus it became the Ariel Square Four, and not the BSA Square Four. Turner was then invited by Jack Sangster to join Ariel.