About Jantar Mantar Delhi, India

front view of jantar-mantar-delhi-india

Jantar Mantar is very popular among tourists and the people of Delhi. The structure is another great masterpiece of Indian architecture which shows the scientific acumen of ancient India. Jantar Manter is situated at Parliament Street, very close to Connaught Place. Jantar Mantar is also called Delhi Observatory. It is maintained by the Jaipur government because it was built by Maharaja Sawai Jai Singh II of Jaipur in 1710 A.D.

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It is a remarkable structure which consists of fourteen geometric devices used for measuring time, forecasting weather changes, predicting behaviour of planets and finding extraterrestrial altitude. All these devices are fixed structures and point to a specific direction. The largest device or instrument is the Samrat Jantar which is 90 feet high and its shadow is plotted in such a manner so that is shows the exact time of the day. Any weather change or the onset of monsoons can be ascertained by the Hindu Chhatri, which is a small domed structure. 

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The whole structure is made of stone and marble with each of then having an engraved astronomical scale. Jantar Mantar finally got the status of a national monument in 1948. It has always attracted architects, historians and scientists from all over the world. 

Maharaja Jai Singh was a fanatical astronomer himself who studied various works from Hindu, Muslim and European astronomy. He had the perception that the tables used by the pundits were deceptive and the actual planetary changes and predictions of eclipses would not have been possible through these measuring parameters. So he thought that he would find an improved and efficient means through which exact prediction could be made. It was his own inspiration and foresightedness that gave shape to such an instrument. He built other observatories at Jaipur, Ujjain, Benares and Mathura to have an exact calculation. It took almost seven years before the whole structure was fully operational because he wanted to be fully satisfied with the accuracy of the instruments at Jantar Mantar.

Some of the major instruments at Jantar Mantar are: 

• The Samrat Yantra 'Prince of Dials' (the largest device)
• The Ram Yantra - two circular buildings
• The Jai Prakash
• The Misra Yantra (north-west to the Samrat Yantra)
• Pillars on the southwest of Mishra Yantra used to measure the shortest and longest days of the year.The Samrat Yantra measured the accurate time of the day. It also measured the declination of the sun which can be seen by the shadow moving around the structure.  

Samrat Yantra in Jantar Mantar, Delhi Observatory : Jantar Mantar

The Samrat Yantra, jantar mantar, delhi

Samrat Yantra or the king of instruments is the largest and the most imposing device in Jantar Mantar, the observatory of Delhi. It is used to measure the accurate time of day and also to measure the declination of the sun. It consists of a triangular indicator with the hypotenuse parallel to earth’s axis.  Built by Jai Singh II of Jaipur, Jantar Mantar is also called Delhi Observatory. It is located in the Parliament Street near Connaught Place. This observatory represents one of the last links with the old school of astronomy.

Rama Yantra in Jantar Mantar, Delhi Observatory : Jantar Mantar

Rama Yantra in Jantar Mantar, Delhi Observatory

The Rama Yantra is located towards the southern edge of the site. It is composed of two complementary hollow cylindrical structures that are open to the sky and positioned close to one other along the north-south axis. The instruments are sunk two meters into the ground, so that the observer has to descend into the instrument to take the readings. Each cylinder is prescribed by a three-tiered circular wall, which steps back gradually from the periphery with every rising tier. The wall is about a meter thick at the bottom, narrowing to ca. 60 centimeters at the top, and is punctured at regular intervals of about a meter with keel-arched openings. The openings in the upper two tiers are about 1.5 meters tall and 1 meter tall in the lowest tier. The curved perforated walls describing the perimeter of each cylinder act as thresholds. Each instrument has a vertical pole marking the centre of the cylinder, which is about a meter and a half in diameter, constructed in stone and covered in plaster. The height of the wall and the pillar is equal to the inner radius of the cylinder. Inside the cylinder, a raised red sandstone floor supported on masonry arches is positioned at a height of one meter from the ground. It is divided into equal sectors radiating out from the central pillar. Every alternate sector has been removed to allow access for taking the readings on the solid sectors. The sectors and openings in one cylinder are the inverse of the other. Like the Jai Prakash Yantra, if the two cylinders were superimposed, they would form a complete cylinder. This division of a single instrument into two complementary units was done mainly to facilitate the readings for celestial bodies at night.

Misra Yantra in Jantar Mantar, Delhi Observatory : Jantar Mantar

The Misra Yantra is located in the northwestern corner of the site. It is a relatively small instrument, and may have been built by Jai Singh's son, Madho Singh (reg. 1751-65) sometime between 1759 and 1799, as the instrument is not mentioned in Jai Singh's accounts. The entire instrument measures about 25 meters across (east-west) and 12 meters north-south. 

Misra Yantra in Jantar Mantar, Delhi Observatory

The Misra Yantra is organized symmetrically about a wall whose upper edge is inclined to the horizontal plane at the same angle as the hypotenuse of the Samrat Yantra. This wall is formed of two walls flanking a staircase used to access the top; while smaller, it is similar to the Samrat Yantra gnomon. The wall is 8 meters high, and and its base stretches for ca. 11 meters. A pair of semicircular scales are located on each side of the gnomon, with their centers located on the hypotenuse of the central wall. These four scales are marble strips, .5 meters wide and supported on individual curved walls. A staircase, about 1 meter long, runs between each pair of scales. The semicircles on the eastern side are inclined at angles corresponding to the meridians of Greenwich and Zurich. Like the hypotenuse, their inclination is upwards from south towards the north. The semicircles on the western side are mirror images of the eastern pair, and correspond to meridians of places in East Asia. This may be coincidental, as the symmetry of the instruments appears to have been the overriding determinant of their inclination. The calibrations on the marble scales can be read by climbing either the staircases located along the outer edge of the curved walls or the staircases in between them. Two doorways, about a meter wide and spanned by segmental arches, puncture the outer curved walls on either side of the gnomon to enable access to the inner staircases. The instrument has three additional quadrants, two on the west and one on the eastern side of the gnomon.