It may be noted that these ere the areas of scientific study in which the Islamic World made the most memorable contribution in the medieval ages and that the Indian subcontinent constituted an important centre for such studies, even after the glory of Damascus and Baghdad had come to end.  As such, these antiques constitute an essential part of our heritage, like the manuscripts, paintings, objects de art and other artifacts.    

            Astrolabes were developed by the ancient Greeks to measure the altitude of a heavenly body. Its theory, manufacture and application was further improved upon and disseminated over a wide region by the Arabs in medieval times. It is often said that the astrolabe was the finest gift of the Islamic world to scientific instrumentation. It appears that the eminent Central Asian scholar, Alberuni introduced the astrolabe to the Indians through his writings. But the manufacture of astrolabes in India began as late as the 14^th century, mainly under the patronage of Firoz Shah Tughluq. His interest in astronomical instruments and experiments is recorded in detail in the anonymous work, Sirat-e Firoz Shahi, the only extant copy of which is available at this Library.  These astrolabes have not survived and the extant astrolabes of Indian origin are from the Mughal period. Humayun patronized astronomy on a large scale and it was under him that some of the finest astrolabes were manufactured. The city of Lahore gained particular fame in this connection. Astrolabes were of different types but the planispheric astrolabe was most common. It was used both for measuring the altitude of heavenly bodies and also for measuring heights and distances in land-surveys. At a more sophisticated level, it could also be used to simulate the motion of heavenly bodies at any given locality and time.

In the 15^th century, the German geographer, Martin Behaim adopted it for navigational purposes to determine latitudes. It proved a decisive factor in encouraging geographical explorations and sea-voyages undertaken by Portuguese and Spanish sea-farers. By the 18^th century, the astrolabe came to be replaced by the sextant in Europe.

            The Celestial Globe was also invented by the ancient Greeks. It represents the vaults of the fixed stars on a three-dimensional basis. Ptolemy has written in detail about both the terrestrial and the celestial globes. His work was updated and further improved by Abd al-Rahman al-Sufi, court-astronomer of the ruler of Isfahan in the late 10 ^th century A.D.