Under the Delhi Sultanate, there was a synthesis of Indian civilization with that of Islamic civilization, and the integration of the Indian subcontinent with a growing world system and wider international networks spanning large parts of Afro-Eurasia, which had a significant impact on Indian culture and society.[70] The time period of their rule included the earliest forms of Indo-Islamic architecture,[71][72] increased growth rates in India's population and economy,[73] and the emergence of the Hindustani language.[74] The Delhi Sultanate was also responsible for repelling the Mongol Empire's potentially devastating invasions of India in the 13th and 14th centuries.[75] The period coincided with a greater use of mechanical technology in the Indian subcontinent. From the 13th century onwards, India began widely adopting mechanical technologies from the Islamic world, including water-raising wheels with gears and pulleys, machines with cams and cranks,[76] papermaking technology,[77] and the spinning wheel.[78]