India- first in history on isolation of Zinc

Before the close of 16^th century,zinc was isolated by a process known neither to the Arab Civilisation nor the Europeans who learnt the art in the early 19^th century. It has now been suggested by archaeological excavations at Zawar in Rajasthan that Indians knew how to isolate zinc by about the 1^st century Christ.

The isolation of zinc was accompanied by another achievement, namely the manufacture of brass, an alloy of copper and zinc. India seems to have discovered the freezing mixture before Europe. Saltpetre (potassium nitrate) was used for cooling water before 1580. This discovery has been attributed to Emperor Akbar.

 

Astronomy in 17th century India

Astronomy was used not only for working out the calender, the dates of the eclipses and for the determination of time but also for casting horoscopes for astrological purposes. Firoza Shah Tughlaq (1351-88) established an observatory where a special type of astrolabe and water clock were set up. The astrolabes made in India during the 17^th century were no doubt an achievement of metal and wood-workers and of mathematical arts. Also, a high degree of accuracy was achieved in circular gradation, which affected all measurements.

The most important stride in the field was made at the beginning ofthe eighteenth century. Raja Jai Singh, under the patronage of Emperor Muhammad Shah, established observatories at a number of places, such as Delhi, Jaipur, Ujjain, Benaras and Mathura. He paid special attention to the instruments for fixing time and determining latitudes.

A familiarity with the knowledge of specific gravity and laws of motion, based on classic sources, was shown by Abu’l Fazl (d. 1603). The application of measures of specific gravity were given a practical turn by Akbar when he sought to determine the

quality of timber.