Ismail al-Jizari's Spare Part
Ismail al-Jizari's Spare Part


Ismail al-Jazari


Wooden cog


Funcions as any replaced machine part


Accelerated fuel consumption


Placing in machine

Collected by

Warehouse 6



Date of Collection




Badīʿ az-Zaman Abū l-ʿIzz Ismāʿīl ibn ar-Razāz al-Jazarī, known colloquially as Amail al-Jazari, was a Muslim polymath: a scholar, inventor, mechanical engineer, artisan, artist and mathematician. He is best known for writing The Book of Knowledge of Ingenious Mechanical Devices in 1206, where he described 100 mechanical devices, some 80 of which are trick vessels of various kinds, along with instructions on how to construct them.

al-Jazari was part of a tradition of artisans and was thus more a practical engineer than an inventor who appears to have been more interested in the craftsmanship necessary to construct the devices than in the technology which lay behind them and his machines were usually assembled by trial and error rather than by theoretical calculation.


When placed in an empty space of a mechanism that would otherwise hold an appropriate part, this small wooden cog will activate. Rotating at high speeds, it will fill the role of any part it replaces. This role can vary from, fittingly, a cog in a sequence to more complicated items like electric cables and motor engines.

The artifact can fill any role it can fit into, though it cannot be used for something smaller than itself. Regardless of how large the missing part is, as long as the cog fits it can function. It cannot replace any part designed to store data or other information, however.

While in use, it doubles whatever means of fuel consumption the mechanism uses. Objects that require kinetic energy will require much more effort to get the machine to move, while electrical or gasoline powered machines will run at a much lower efficiency.

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