One fine day in 1719, the courtiers of Mughal Emperor Muhammad Shah were embroiled in a heated argument about how to accurately calculate the auspicious date and time for the Emperor’s travel plans. While they were arguing with each other, one member of the Durbar was sitting quietly thinking, ‘why don’t we have an instrument which can give very accurate date and time ?’ inspired by this thought, this courtier decided that he will construct a high precision astronomical observatory. NRI Achievers brings you here a story about what followed …

The thoughtful courtier mentioned in the introduction was none but Saramad-i-Rajaha-i-Hind, Raj Rajeshwar, Shri Rajadhiraj, Maharaja Sawai Jai Singh II, Maharaja of Amer (and later Jaipur). He was an ally of the Mughals and had great interest in mathematics, architecture and astronomy. After the debate in court, he held a discussion with the Mughal Emperor and took his approval on constructing astronomical observatories.
Jai Singh was influenced primarily by the Islamic school of astronomy. He studied the work of the great astronomers. Early Greek and Persian observatories contained elements that Jai Singh incorporated into his designs, but the instruments of the Raja Jai Singh’s observatories are more complex, or at a much greater scale than any that had come before, and in certain instances, are completely unique in design and function.
The first observatory was built in Delhi. Some people argued that the observatory was built in 1710, but Sir Syed Ahmed Khan, author of Athar-us-Sanadid correctly calculates the date as 1724. Raja Jai Singh had his estate near Delhi, which was known as Jaisinghpura. This estate today comprises of the area from the foot-hill of Raisina to Janpath and parts of Connaught Place.
His palace/haveli/bangla was used by the 8th Sikh Guru and is today known as Gurudwara Bangla Sahib.

After this first observatory in Delhi, he built similar observatories in Amer (now called Jaipur), Benaras, Ujjain and Mathura. The Mathura observatory was painfully demolished by land mafia. Out of the other 4, only the largest sundial, the Jaipur observatory, is operational because the other three are now surrounded by high rise buildings or trees, thus obstructing direct sunlight. All these observatories are accurate to the half of a second, which is far far better than European instruments available at that time.
Originally, these observatories were called “Yantra” or “Yantar”. In many north Indian accents, people often pronounce “Y” as “J”. Thus, Yantar soon became Jantar. “Mantar” means a formula, or in this context, a calculation. Thus we get the present name for these observatories “Jantar Mantar”.

Did You Know ?

A Jantar Mantar complex comprises multiple ‘Yantras’ (instruments). Each instrument serves its own unique task. Instruments from the Delhi Jantar Mantar complex include …

Samrat Yantra (supreme instrument): is ‘an equinoctial dial. It comprises a triangular gnomon (from the greek, literally meaning, “one who knows or examines”, is the part of a sundial that casts the shadow.) with the hypotenuse parallel to the earth’s axis, and on either side of the gnomon is a quadrant of a circle parallel to the plane of the equator’.
Jai Prakash Yantra: This consists of two concave hemispherical structures to ascertain the position of the sun and other heavenly bodies. It has a long tower with stairs attached to it, from which experts would accurately calculate time.
Ram Yantra: These are twin structures, circular in shape with a pillar in centre, the walls and floor of which are graduated for reading horizontal (azimuth) and vertical (altitude) angles.
Misra Yantra (mishrit/mixed instrument): This combines multiple instruments in one. These are:
• Niyata Chakra: Indicates the meridian at four places, two in Europe and one each in Japan and the Pacific Ocean; half on an equinoctial dial
• Dakshinottara-bhitti-Yantra: This one is used for obtaining Meridian Altitudes
• Karka-rasi-valaya Yantra: This instrument indicates the entry of the Sun into the Cancer
The Jaipur Jantar Mantar on the other hand consists of 14 major instruments. These also include the instruments from Delhi Observatory. Each of the instrument is carefully angled at the latitude of the location where it is built. The height of each building and its marking are very carefully calibrated and an expert can predict eclipses, tell time, track stars and determine celestial altitudes and related ephemerides.

Jantar Mantars are instruments of high precision and excellent craftsmanship. Unfortunately, while we have lost this art to modern clocks, we still revere and respect the talent and hard work of our forefathers, who have made this modern day possible.

Vikramjit Singh Rooprai

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