Overview:
This article delves into the complex histories of the mechanical clock, the magnetic compass, and perpetual motion devices. The author, Derek J. de Solla Price, challenges the traditional view of the clock’s ancestry, arguing that its true origin lies not in sundials or water clocks, but in intricate astronomical machines developed across three continents over two millennia.
Price argues that the mechanical clock evolved from these protoclocks, which were initially designed to illustrate the movements of celestial bodies. He explores the development of these devices in China, where a unique mechanical escapement was invented, and in the Hellenistic world, where the Antikythera mechanism, a complex astronomical calculator, is believed to have been created in the 1st century BCE. He further examines the transmission of astronomical knowledge from the Islamic world to medieval Europe, focusing on the contributions of al-Biruni, who developed a geared astrolabe around 1000 CE, and Richard of Wallingford, who built a planetary clock in the 14th century.
Key Findings:
- The mechanical clock originated from astronomical machines, not from simpler time-keeping devices.
- The invention of the mechanical escapement, a crucial component of the clock, can be traced back to China, where it was used in astronomical clock towers.
- The concept of perpetual motion played a significant role in the development of the clock, with early references to “self-moving wheels” occurring in conjunction with astronomical devices.
- The magnetic compass likely originated in China and was transmitted to Europe, possibly along the Silk Road or through travelers during the Crusades.
Learning:
- The evolution of the mechanical clock: The reader will learn how the mechanical clock emerged from a rich tradition of astronomical devices designed to model the heavens. This lineage spans centuries and multiple cultures, highlighting the interconnectedness of scientific and technological progress.
- The significance of the Chinese escapement: The article highlights the crucial invention of the mechanical escapement in China, showcasing the ingenuity and independent development of technology in the East.
- The impact of perpetual motion: The reader will gain insight into the fascination with perpetual motion devices and how this pursuit ultimately contributed to the development of the clock.
- The origins of the magnetic compass: The text sheds light on the likely Chinese origins of the magnetic compass and the transmission of this innovation to Europe. This highlights the importance of intercultural exchange in the advancement of technology.
Historical Context:
The article was written in 1959, during a period of renewed interest in the history of science and technology. It reflects the growing understanding of the interconnectedness of scientific and technological development across cultures and time periods.
Facts:
- The earliest known example of gearing dates back to the 4th century BCE in China. This is evidenced by preserved gear wheels and molds for wheels.
- The Antikythera mechanism, discovered in 1901, is believed to be a complex astronomical calculator dating back to 65 BCE, demonstrating the advanced technological capabilities of the Hellenistic Greeks.
- The Chinese invented a mechanical escapement around 725 CE, which was used in astronomical clock towers. This escapement mechanism allowed for the precise regulation of the clockwork.
- The Alfonsine corpus, a collection of scientific texts produced in 13th-century Spain, includes descriptions of a mercury clock, which used a mercury drum as an escapement. This innovative device showcases the ingenuity of Islamic scientists and engineers.
- The first complete account of a magnetic compass with a pivoted needle and a circular scale was written by Peter Peregrinus in 1269. This work also includes a description of a perpetual motion wheel powered by a magnet.
- The earliest known reference to a magnetic compass in Europe dates back to 1187, when Alexander Neckham described a floating magnet with a pointer.
- The first known reference to a magnetic compass in Persia dates back to around 1230, suggesting that the compass was introduced to the Islamic world from China.
- The “self-moving wheels” described in early texts are often linked to astronomical devices, suggesting a connection between the pursuit of perpetual motion and the development of clockwork.
Statistics:
- The Antikythera mechanism is estimated to have been built around 65 BCE, making it one of the most sophisticated pieces of technology from antiquity.
- The Chinese escapement invented around 725 CE could regulate the clockwork for a period of about 15 minutes.
- Su Sung’s astronomical clock tower, built in 1090, was approximately 30 feet tall and incorporated a variety of features, including an armillary sphere, a celestial globe, and a striking mechanism with figures that announced the time.
- The geared astrolabe of al-Biruni, developed around 1000 CE, used a gear train with a specific ratio to represent the revolutions of the sun and moon.
- The Alfonsine mercury clock, described around 1272, used a mercury drum with 12 chambers to regulate the clockwork.
Terms:
- Protoclock: An early astronomical machine designed to illustrate the motions of celestial bodies.
- Escapement: A mechanism that regulates the release of energy in a clock, controlling the speed and accuracy of the timekeeping.
- Armillary Sphere: A model of the celestial sphere composed of rings representing important celestial circles.
- Anaphoric Clock: An early astronomical clock that displayed the positions of stars on a rotating disk.
- Astrolabe: An instrument used to determine the position of stars and planets.
- Equatorium: A mechanical model used to simulate the geometrical constructions necessary for finding planetary positions.
- Terrella: A spherical magnet used to study the properties of Earth’s magnetism.
- Loadstone: A naturally occurring magnetic rock.
- Perpetuum Mobile: A hypothetical machine that would run forever without any external source of energy.
Examples:
- The Antikythera mechanism: This complex astronomical calculator, dating back to the 1st century BCE, is a prime example of the sophisticated technological achievements of the Hellenistic Greeks. It used a system of gears to track the positions of the sun, moon, and planets.
- Su Sung’s astronomical clock tower: This impressive structure, built in 1090 CE, incorporated a water-powered mechanism with a mechanical escapement to regulate the rotation of an armillary sphere and a celestial globe. It also featured a striking mechanism with figures that announced the time.
- Al-Biruni’s geared astrolabe: This remarkable instrument, developed around 1000 CE, used a series of gears to calculate the positions of the sun and moon, demonstrating the ingenuity of Islamic astronomers.
- Peter Peregrinus’ magnetic perpetual motion wheel: This device, described in 1269, attempted to harness the power of magnets to create a perpetual motion machine.
- Richard of Wallingford’s planetary clock: This complex astronomical clock, built around 1320, was said to have been capable of showing the positions of the planets, highlighting the sophistication of medieval European clockwork.
Conclusion:
This article offers a compelling argument for the interconnectedness of scientific and technological development across cultures and time periods. It reveals that the mechanical clock, the magnetic compass, and perpetual motion devices share a fascinating history that is woven together by a series of transmissions and re-inventions. The pursuit of perpetual motion, in particular, played a significant role in the development of the clock, while the Chinese invention of the mechanical escapement likely influenced the course of clockmaking in Europe. This article serves as a reminder that the history of technology is not a linear progression but rather a complex and dynamic process shaped by collaboration, exchange, and innovation across cultures.