Sawai Jai Singh II builds the Jantar Mantar observatories
- Date
- c. 1724
- Category
- Science, technology & invention
- Region
- South Asia (northern India: Delhi, Jaipur, Ujjain, Mathura, Varanasi)
- Era
- Early Modern
- Significance
Around 1724, Maharaja Sawai Jai Singh II of Amber and Jaipur, a Rajput astronomer-king serving under the Mughal emperor Muhammad Shah, began constructing a series of monumental masonry astronomical observatories in northern India, collectively known as the Jantar Mantar.
The first was erected at Delhi, followed over the next decade and a half by observatories at Jaipur, Ujjain, Mathura, and Varanasi (Benares), with instrument-building at Jaipur continuing until about 1738. Frustrated by inaccuracies in existing astronomical tables and the wear of small brass instruments, Jai Singh designed enormous fixed structures of stone and plaster—such as the towering Samrat Yantra sundial—to achieve greater stability and precision in tracking the Sun, Moon, and planets with the naked eye. The data gathered informed his astronomical tables, the Zij-i Muhammadi Shahi, which were used across India for roughly a century. Blending Hindu, Islamic, and European astronomical traditions, the observatories represent one of the most ambitious scientific undertakings of the late Mughal era; the Jaipur site was inscribed as a UNESCO World Heritage Site in 2010.
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Empires active in c. 1724
- Spanish Empire1492 CE – 1976 CE
- Portuguese Empire1415 CE – 1999 CE
- Mughal Empire1526 CE – 1857 CE
- Qing Dynasty1636 CE – 1912 CE
- British Empire1583 CE – 1997 CE
- Russian Empire1721 CE – 1917 CE
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- Arkwright's Cromford Mill and the birth of the factory system1771 (water frame patented 1769)
Further reading
The wider story
A Little History of Science
Warm, jargon-free tour of discovery from Babylonian stargazers to the genome.
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