Anchor escapement teeth, which made the escape wheel rotate once per minute so the second hand could be attached to its shaft. In a 30 tooth escape wheel the pallets span about 7½ teeth. The impulse angle of the pallets, which determined the swing of the pendulum, was 3°-4°. The anchor was the second widely used escapement in Europe, replacing the 400-year-old verge escapement in pendulum clocks. The pendulums in verge escapement clocks had very wide swings of 80° to 100°. In 1673, seventeen years after he invented the pendulum clock, Christiaan Huygens published his mathematical analysis of pendulums, "Horologium Oscillatorium". In
Coaxial escapement beat movements, he has also noted that they aggravate the problem of sliding friction in the escapement (at the escape teeth and pallets). Higher beat movements produce increased speed and pressure at these critical surfaces." Coaxial escapement The coaxial escapement is a type of modern watch escapement mechanism invented by English watchmaker George Daniels. Invented around 1974 and patented in 1980 by English watchmaker George Daniels, the coaxial escapement is a modification of the lever escapement with some features of the detent escapement. Considered by some to be one of the most significant horological advancements since the invention of the