Yantra Madir - Jantar Mantar

A quick guide to the specific use of the curious instruments in Yantra Mandir (as depicted at Jantar Mantar, Jaipur, Rajathan):

The Ram Yantra can measure the local coordinates of altitude and azimuth of celestial objects.

Jai Prakash Yantra is used to find the positions of the celestial bodies during day and night..

The Dhruva Yantra is used to locate the position of 12 Zodiac signs and also the Pole Star at night.

The Narivalya Yantra is a distinctive sundial with two dials - the first dial facing south reads time when the sun is in the southern hemisphere, i.e., from 21 September to 21 March and the other one facing north reads time for the rest of the year when the sun is in the northern hemisphere, i.e., from 21 March to 21 September.

The Krantivrtta is an instrument that is meant to measure the celestial latitude and celestial longitude of an object in the sky. It is also used for measuring solar sign of the Sun in day time.

The Yantra Raj is an adaptation of an Astrolabe - a Medieval instrument for the measurement of time and the position of celestial objects.
The instrument is used for measuring ascendants, altitude, time and the position of the Sun and that of some other celestial objects in the sky. It can also be used in the computation of celestial positions and their changes. The instrument also measures time from the positions of stars in the night, and that of the Sun in the day.

Unnatamsa for measuring altitude - the angular height of an object in the sky.

Chakra yantra gives the angle of an object from the equator.

Disha yantra or the compass always points to the north.

Dakshinottra Bhitti measures the altitude of the angular height of a celestial object when it crosses the meridian.

Laghu Samrat Yantra is a sundial that can give the time to an accuracy of 20 seconds.

Rashivalayas Yantra has 12 sundials for the signs of the zodiac.

Note: The traditional unit of measurement started with the smallest unit being 'human breath' that has been calculated to be of 6 seconds duration.


These structures remind us of the role of light and time in our everyday life !

Largest Sundial in the World !

A sundial is a device that measures time by the position of the Sun.

Standing 27 metres (90 feet) tall and with a base length of 147 feet, the Vrihat Samrat Yantra (The Large Supreme Instrument) is the world’s largest sundial !

It is housed in Jantar Mantar ( literally means 'calculation instrument') in Jaipur, in the state of Rajasthan.

It’s shadow moves visibly at 1 mm per second, or roughly a hand's breadth (6 cm) every minute,
It's face is angled at 27 degrees, the latitude of Jaipur. The Hindu chhatri (small cupola) on top is used as a platform for announcing eclipses and the arrival of monsoons.

Used for calculating the time of the day to the exact second using the position of the dial and the shadow it casts from the sun, it has an accuracy of about two seconds. If an astronomical observer knew the time it took a prominent star to transition the sky, they could even use the Yantra to tell the time at night.

Live the BIG Life !

Largest Stone Astronomical Observatory in the World !

Located across the road from the City Palace, Jantar Mantar, was our next destination in Jaipur.

It:
- Was built between 1727 and 1733.
- Is the largest stone astronomical observatory in the world !
- Has the biggest sundial in the world !
- Is one of the largest and the only working observatories of the five, built by Sawai Jai Singh II (the others were built in Delhi, Mathura, Benaras and Ujjain)
- Houses a large collection of around 20, huge masonry astronomical instruments, each with a specific astronomical use. The main reason to build these large stone structures on a grand scale was to enhance the accuracy of the measurements.
- Has been recently (in July 2010), added to the World Heritage list, by UNESCO, as a cultural site.
- According to UNESCO, the site "is the most significant, most comprehensive, and the best preserved of India's historic observatories."



As listed on the National Geographic site, the other astronomical site added to the World Heritage list is part of the monuments at "The Centre of Heaven and Earth"—a sacred mountain in China's Henan Province.
The site includes the Zhougong Sundial Platform and the Dengfeng Observatory, built about 700 years ago at the beginning of the Yuan Dynasty (A.D. 1271-1368) by astronomer Guo Shoujing.
Reference: http://blogs.nationalgeographic.com/

I admire our astronomers and masons of yesteryears who conceived and built these amazing masonary instruments used to study the movement of constellations and stars in the sky !