The method of water-lift based on pin-drum gearing known as Persian wheel had been introduced during Babur’s time.  

• A complicated system of water lift by a series of gear-wheels had been installed in Fatehpur Sikri.  
• Akbar was also credited with popularizing the device of cooling water using saltpetre. 
• In metallurgy, the inability to produce cast iron remained an obvious drawback.  

• As Irfan Habib observed, ‘India’s backwardness in technology was obvious when the matchlock remained the most common weapon in Indian armies. In Europe the flintlock had long come into use.  
• Indians continued to use the expensive bronze cannon, long after these had become obsolete in Europe.  
• This was because of India’s inability to make cast iron even in the seventeenth century.’ 

Source: Tamil Nadu state board.