Important timurid astronomy. Ali Qushji (d. 1474) was an important Timurid scholar best known for his development of astronomical physical independent form natural philosophy and for providing empirical evidence for the earth's rotation. He is also known to have improved on Nasir al-Din Tusi's planetary model and presented an alternative view of the planet Mercury.

Qushji was a very close disciple of Ulugh Beg and was assigned to work in the Ulugh Begh Observatory (Samarkand) for a period of time where he worked as a contributor on Ulugh Beg's famous Zij'i Sultan (an Astronomical table and star catalogue compiled between 1438 and 1439 AD by Qushji and the most prominent Timurid astronomers of the period).

Single volume, decorated manuscript on paper, in Farsi, 77 leaves, single 14 lines elegant black nasta'liq, many diagrams of planets and cosmology throughout, many in red, catch-words, first leaf a little chipped and torn with slight loss, overall clean internal condition; later limp leather, clean and attractive volume. 168 x 95mm (6½ x 3¾ inches).