Al-Hayl

Written by Ahmad bin Musa bin Shak­er Khorasani, it is an old work about au­tomatic mechanical tools and utensils; Ahmed bin Musa along with his brothers, Hasan and Muhammad, with the title Banu Shakir, both in terms of the contribution they had in the translation movement from Greek to Arabic and also because of the role they played in the political, scientific, and cultural life of the first half of the third century of the Islamic calendar. , were al­ways considered. The date of birth of none of these three brothers is known.

Kitab al-Hayl has described a hundred devices, more than eighty of which are various entertaining devices and amazing dishes, and the rest of them include the fol­lowing items.

Fountains whose shape changes periodi­cally:

B: A lamp whose flame is regulated by itself and burns by itself

takes

C: A kind of tail to expel the polluted air from the wells.

D: A fork for digging in the bottom of the sea and river.

The description of each device is relatively short and about one or two pages with a picture. The letters of the alphabet are writ­ten on the pictures and referred to in the text of the book.