wheel has made 1 revolution, the carriage will have gone 10 li and the figure in the upper storey will strike the bell. The number of wheels used, great and small, is 8 inches in all, with a total of 285 teeth. Thus the motion is transmitted as if by the links of a chain, the "dog-teeth" mutually engaging with each other, so that by due revolution everything comes back to its original starting point (ti hsiang kou so, chhuan ya hsiang chih, chou erh fu shih). Subsequent developments Odometers were first developed in the 1600s for wagons and other horse-drawn vehicles in order to measure distances traveled. Levinus Hulsius published the odometer in 1604 in his work Gründtliche Beschreibung deß Diensthafften und Nutzbahrn Instruments Viatorii oder Wegzählers, So zu Fuß, zu Pferdt unnd zu Fußen gebraucht werden kann, damit mit geringer mühe zu wissen, wie weit man gegangen, geritten, oder gefahren sey: als auch zu erfahren, ohne messen oder zehlen, wie weit von einem Orth zum andern. Daneben wird auch der grosse verborgene Wegweiser angezeiget und vermeldet. In 1645, the French mathematician Blaise Pascal invented the pascaline. Though not an odometer, the pascaline utilized gears to compute measurements. Each gear contained 10 teeth. The first gear advanced the next gear one position when moved one complete revolution, the same principle employed on modern mechanical odometers. Odometers were developed for ships in 1698 with the odometer invented by the Englishman Thomas Savery. Benjamin Franklin, U.S. statesman and the first Postmaster General, built a prototype odometer in 1775 that he attached to his carriage to help measure the mileage of postal routes. In 1847, William Clayton and Orson Pratt, pioneers of the Church of Jesus Christ of Latter-day Saints, first implemented the Roadometer they had invented earlier (a version of the modern odometer), which they attached to a wagon used by American settlers heading west. It recorded the distance traveled each day by the wagon trains. The Roadometer used two gears and was an early example of an odometer with pascaline-style gears in actual use. In 1895, Curtis Hussey Veeder invented the Cyclometer. The Cyclometer was a mechanical device that counted the number of rotations of a bicycle wheel. A flexible cable transmitted the number of rotations of the wheel to an analog odometer visible to the rider, which converted the wheel rotations into the number of miles traveled according to