Invented in 1656, what was the most reliable time-keeping technology until the 1930s?
Christiaan Huygens others to whom such a lantern device has been attributed, such as Giambattista della Porta, and Cornelis Drebbel: the point at issue is the use of a lens for better projection. Athanasius Kircher has also been credited for that. Huygens designed more accurate clocks than were available at the time. In 1656, inspired by earlier research into pendulums by Galileo Galilei, he invented the pendulum clock, which was a breakthrough in timekeeping and became the most accurate timekeeper for the next 275 years until the 1930s. Huygens contracted the construction of his clock designs to Salomon Coster in The Hague,
Technology of the Discworld of Magic", but declines because the clockwork watches now made in Ankh-Morpork are more reliable. This may be an allusion to the relative speeds of technological development in Europe and China; China (of which the Agatean Empire is clearly a version) was much more advanced than Europe until the Industrial Revolution, when Europe rapidly surpassed it. In "Jingo", Klatch is also represented as being technologically advanced; a telescope which had recently been invented in Ankh-Morpork is old technology in Klatch. However, there is no indication that Klatch is advancing (an allusion to the technological advancement of the Second Persian and