The Book of Ingenious Devices (, ) is a large illustrated work on mechanical devices, including automata, published in 850 by the three brothers of Persian descent, the Banū Mūsā brothers (Ahmad, Muhammad and Hasan ibn Musa ibn Shakir) working at the House of Wisdom (Bayt al-Hikma) in Baghdad, Iraq, under the Abbasid Caliphate. The book described about one hundred devices and how to use them.
Overview
The book was commissioned by the Abbasid Caliph of Baghdad, Al-Ma'mun (786–833), who instructed the Banū Mūsā brothers to acquire all of the Hellenistic texts that had been preserved by monasteries and by scholars during the decline and fall of Roman civilization. The Banū Mūsā brothers invented a number of automata (automatic machines) and mechanical devices, and they described a hundred such devices in their Book of Ingenious Devices.
Some of the devices described in the Book of Ingenious Devices were inspired by the works of Hero of Alexandria and Philo of Byzantium, as well as ancient Persian, Chinese and Indian engineering. Many of the other devices described in the book, however, were original inventions by the Banū Mūsā brothers. While they took Greek works as a starting point, the Banu Musa went "well beyond anything achieved by Hero or Philo." Their preoccupation with automatic controls distinguishes them from their Greek predecessors, including the Banu Musa's "use of self-operating valves, timing devices, delay systems and other concepts of great ingenuity." Many of their innovations involved subtle combinations of pneumatics and aerostatics. The closest modern parallel to their work lies in control engineering and pneumatic instrumentation.
In turn, the Banū Mūsā brothers' work was later cited as an influence on the work of al-Jazari, who produced the Book of Knowledge of Ingenious Mechanical Devices in 1206. Given that the Book of Ingenious Devices was widely circulated across the Muslim world, some of its ideas may have also reached Europe through al-Andalus, such as the use of automatic controls in later European machines or the use of conical valves in the work of Leonardo da Vinci.
Mechanisms and components
Automatic controls
The Banu Musa brothers described a number of early automatic controls. Two-step level controls for fluids, an early form of discontinuous variable structure controls, were developed by the Banu Musa brothers. They also described an early feedback controller. Donald Routledge Hill wrote the following on the automatic controls underlying the mechanical trick devices described in the book:
The Banu Musa also developed an early fail-safe system for use in their trick devices, as described by Hill:
Automatic crank
The non-manual crank appears in several of the hydraulic devices described by the Banū Mūsā brothers in their Book of Ingenious Devices. These automatically operated cranks appear in several devices, two of which contain an action which approximates to that of a crankshaft, anticipating Al-Jazari's invention by several centuries and its first appearance in Europe by over five centuries. However, the automatic crank described by the Banu Musa would not have allowed a full rotation, but only a small modification was required to convert it to a crankshaft.
Valves
A mechanism developed by the Banu Musa, of particular importance for future developments, was the conical valve, which was used in a variety of different applications. This includes using conical valves as "in-line" components in flow systems, which was the first known use of conical valves as automatic controllers. Some of the other valves they described include:
Plug valve
Float valve
Tap
Other mechanisms
The double-concentric siphon and the funnel with bent end for pouring in different liquids, neither of which appear in any earlier Greek works, were also original inventions by the Banu Musa brothers. Some of the other mechanisms they described include a float chamber and an early differential pressure sensor.