Monument: Exploring Jantar Mantar


Ebenzer Samuel said – “Wilful obedience to God’s will is the only way to be guided by him in this Jantar Mantar world.”

Jantar Mantar – New Delhi

Humans can never be limited by confining their knowledge to terrestrial matters. Jantar Mantar at New Delhi is one of the five observatories that were built by Sawai Jai Singh II between 1724 and 1730.

The decision to build these observatories was a quest for accuracy and the ability to compare readings from different coordinates. It is also noteworthy that the sites Jai Singh chose have historical, political or religious significance. Delhi was an ancient city and the seat of the Mogul Empire.


The word Jantar Mantar was formed collectively with the Sanskrit words -Yantra and Mantra, which were used as the basic elements to make the observatory work. Situated near Connaught Place, New Delhi, Jantar Mantar has a special place amongst the numerous observatories erected by Maharaja Jai Singh II of Jaipur. It basically comprises of the instruments that were used for keeping track of celestial bodies. When Maharaja Jai Singh found that the existing astronomical instruments were too small to take correct measurements, he built these larger instruments. Delhi Jantar Mantar is a reminder of the technological achievements that took place under the Rajput Kings. It is an excellent example of the amalgamation of the universe, society and belief. It was designed for the observation of astronomical positions with the naked eye.


There is an interesting legend associated with the construction of the Jantar Mantar. It is said that Maharaja Jai Singh oversaw an argument between scholars over certain planetary positions. Since it was necessary to solve the issue and know the positions precisely, he offered to rectify the astronomical tables. This offer was accepted by the Mogul emperor and that led to the construction of the Jantar Mantar in Delhi. Initially, brass instruments were used in the observatory but they had intrinsic flaws. So, Sawai Jai Singh adopted the style of Prince Ulugh Beg, builder of the 15th century observatory at Samarkand, Uzbekistan. This is how the Delhi Jantar Mantar became what it is today.


The Delhi Jantar Mantar is one of the five observatories built by the Maharaja of Jaipur, Sawai Jai Singh II. After the completion of the Jantar Mantar, the observatory was functional for seven years. Data of each day was collected and charted and dedicated to the reigning emperor. It bears witness to the high standard of scientific knowledge in Indians.


It consists of mason built astronomical instruments to chart the positions of different planets, the Sun and the Moon. The Jantar Mantar observatory in Delhi is a camouflage in modern art. 

The ‘yantras’ or instruments are-

  • Samrat Yantra 
  • Jaya Prakash Yantra
  • Ram Yantra
  • Misra Yantra
  • Dakshinottarbhitti Yantra
  • Agra Yantra
  • Niyati Chakra

The instruments used in the observatory were built on brick rubble and plastered with lime. These were the basic elements used to make various astronomical calculations.

Uses of instrumental structures 

Samrat Yantra-

The Samrat Yantra is a giant triangle that is basically an equal hour sundial. It is 70 feet high, 114 feet long at the base and 10 feet thick. It has a 128-foot-long hypotenuse that is parallel to the earth’s axis and points towards the North Pole. On either side of the triangle is a quadrant with graduations indicating hours, minutes and seconds. It is said that, at the time of the Samrat Yantra’s construction, sundials already existed, but the Samrat Yantra turned the basic sundial into a precision tool for measuring declamation and other related coordinates of various heavenly bodies.

Jayaprakash Yantra- 

The Jaya Prakash Yantra was constructed for measuring the sun’s position at the time of equinox. It consists of hollowed out hemispheres with markings on their concave surfaces. Cross wires were stretched between points on their rim. From inside, an observer could align the position of a star with various markings on a window edge.

Ram Yantra- 

The Ram Yantra was used for measuring the altitude of stars. Two large cylindrical structures with open top were used to measure the altitude of stars based on latitude and longitude on the earth.

Misra Yantra-

The Misra Yantra is a composition of five instruments designed as a tool to determine the shortest and longest day of the year. The appearance of this measurement is similar to ‘Namaste’ form. The best part about the Jantar Mantar Delhi is the Misra Yantra or the mixed instrument near the main entrance. Even today this instrument is capable of depicting the time of four other places in the world accurately when it is noon in Delhi.

Dakshinottarbhitti Yantra-

This instrument was used for maintaining meridian altitudes. The Karka-Rashi-Valaya of the instrument revealed the entry of the Sun in cancer constellation.

Agra Yantra- 

This is the second quadrant on the west side of the building.

Niti Chakra- 

The Niti Chakra indicates the time zones that is Zürich, Serichew and Greenwich.

Architectural style 

Jantar Mantar is an array of astronomical instruments. It consists of architectural astronomical instruments made up of geometric devices.

Interesting facts 

  • Although a total of five Jantar Mantars were built by Sawai Jai Singh II between 1717 to 1737, only four remain.
  • The sundial measures the time of a day, correct to half a second.
  • Jantar Mantar’s sculptural structures have inspired several contemporary art pieces.
  • Most of the instruments depend on sunlight, so to understand how they work, a sunny day is required.
  • During 1982, in the Asian Games held in New Delhi, Jantar Mantar was used on the logo of the event.


This marvel reflects the endeavour of the Rajput Kings to unravel the mysteries pertaining to astronomy and the technological achievements made by the Indians. The Jantar Mantar remains an integral part of India’s scientific heritage and a significant monument of the history of astronomy.

Jantar Mantar – Jaipur 

The city of Jaipur was founded by Maharaja Jai Singh in 1726 to become the new capital of his kingdom.

Jantar Mantar literally means ‘instruments for measuring the harmony of heavens’. The Jaipur observatory was built during 1728-34. It is a monumental example of masonry of known instruments. This is the most significant, most comprehensive and the best preserved of India’s historic observatories.


Jantar Mantar of Jaipur is a World Heritage Site. It has the largest sundial of the world. Sawai Jai Singh was an accomplished scholar himself and was commissioned the task of confirming and rectifying the current data available on the movement of celestial bodies. He wanted to define a precise calendar and make accurate astronomical predictions for both individual and social benefit. His another aim was to apply the cosmological vision derived from the Ptolemaic one based upon astronomical facts to astrological predictions. Sawai Jai Singh was aware of the Hindu tradition of astronomical data and he also studied all the astronomy related books and data of Europeans, Islamic and Persian civilisation.


The observatory forms part of a tradition of Ptolemaic positional astronomy which was shared by many civilisations. It contributed by this type of observation to the completion of the astronomical tables of Zij. It is an amalgamation of political, scientific and religious needs. The observatory bears witness to very ancient cosmological, astronomical and scientific tradition shared by a major set of Western, Middle Eastern, Asian and African religions as well.

Ancient texts 

The earliest discussion of astronomical instruments, gnomon and clepsydra is found in Vedangas, ancient Sanskrit texts. The gnomon found at the Jantar Mantar monument is discussed in these first millennium BCE Vedangas and in many later texts such as Katyayan Sulbasutras. Other discussions of astronomical instruments can be seen in the Hindu texts such as Arthashastra, Buddhist text as Sardulkarna – avdana and Jain texts such as Suriya Prajnapati.

Materials used 

Each instrument, built of local stone and marble, carries an astronomical scale, generally marked on the marble inner lining. Bronze tablets, bricks and mortar were also employed in building the instruments in the monument spread over about 18,700 square meters.

Is it authentic?

The observatory of Jantar Mantar at Jaipur has been affected by its outdoor situation and then by its abandonment in the 19th century, which has resulted in frequent maintenance, interventions and then various restorations. Its authenticity is unquestionable, with regards to the astronomical function, it is more difficult to establish with plasters, instrument graduation, some architectural interpretations and the immediate landscape environment.


The Jantar Mantar Jaipur is a compilation of 19 architectural, astronomical instruments. The structures at large scale have always captivated the attention of architects, artists and art historians worldwide. The Jantar Mantar at Jaipur comprises of 19 instruments to measure the position and distance of extra-terrestrial bodies. These instruments are basically stone structures depicting interesting geometric shapes. The major instruments here are –

Virat Samrat Yantra-

It is the largest sundial ever built with a gnomon arm 22.6 m high and the largest quadrants of radius 15.5 m. The western and eastern quadrants are divided into six hours each, for the morning and the afternoon segments respectively.  Each hour is divided in 15 minutes and later in one-minute parts. The Hindu Chhatri on top is used as a platform for announcing eclipses and the arrival of monsoons. The Samrat Yantra, translating to ‘supreme instrument’ is an equinoctial sundial and measures time up to the precision of two seconds. The shadow of the triangular wall of the Yantra, which is positioned in the North-South direction with an angle identical to the latitude of this location, travels equal distances in equal intervals of time, on the eastern and western quadrants. This movement is standardised to calculate and interpret the local time.

Laghu Samrat Yantra-

It is smaller in size and calculates time up to the accuracy of 20 seconds. The Laghu Samrat Yantra is popular as the Small Samrat Yantra. The ramp of this sundial points towards the North Pole, hence Jaipur time can be easily calculated from the position of the ramp’s shadow on the fine division of the carved scale.

Ram Yantra-

The Ram Yantra measures elevation and azimuth of the Sun and planets. The instrument comprises a pair of tube-shaped structures, open to the Sky. Each structure has a pole of equal height at the centre. Scales indicating angles of altitude and azimuth of extra-terrestrial bodies are inscribed inside the walls of these structures. The Ram Yantra is only seen in the Jantar Mantar of Jaipur and Delhi.

Jaya Prakash Yantra- 

This is the main attraction of the Jantar Mantar of Jaipur. This Yantra consists of two hemispherical bowls like sundials with graded marble slabs. The inverted image of the Sky falls on the slab and the movement of the inverted shadows helps to detect the elevation azimuth, hour angles and exact position of heavenly bodies.

Chakra Yantra-

The Chakra Yantra is a ring instrument which calculates the coordinates and the hour angle of the Sun. It consists of four semi-circular arcs, on which the gnomon throws a shadow, hence deducing the declination of the sun four times in a day.

Digamsa Yantra-

It is a pillar in the middle of two concrete outer circles, which helps to predict the sunrise and sunset timings in a day.

Nadivalaya Yantra-

With two circular plates, facing north and south, the Nadivalaya Yantra represents the two hemispheres of the Earth. The wall of the plates is inclined at such a gradient, that the instrument is always parallel to the Earth’s equatorial plane.

Karnti Vritya Yantra-

This is a special instrument used to measure the solar sign of the Sun in the daytime.

Yantra Raj-

The Yantra Raj is an adaptation of an astrolabe, a medieval instrument for measurement of time and the position of celestial objects.

Unnatmasha Yantra- 

This is a metal ring divided into four segments by horizontal and vertical lines, with a hole in the middle, the position and orientation of the instrument allows the measurement of the altitude of celestial bodies.

Dakshin Bhitti Yantra-

It is used to measure meridian altitude and zenith distances of celestial bodies.

Disha Yantra- 

It is the compass and always points to the north.

Dhruva Darshak Pattika-

This instrument is used to observe and find the location of Pole Star with respect to other celestial bodies.

Kapali Yantra-

The Kapali Yantra measures the coordinates of celestial bodies in azimuth and equatorial systems, any point in Sky can be visually transformed from one coordinate system to another.

Misra Yantra- 

The Misra Yantra means mixed instrument. It is a compilation of five different instruments.

Rashi Valaya Yantra-

It contains 12 gnomon dials that measure ecliptic coordinates of stars, planets and all twelve constellation systems.

Shastansh Yantra-

This instrument is the 60° arc built in the meridian plane within a dark chamber. At noon, the Sun’s pinhole image falls on a scale below enabling the observer to measure the zenith distance, declination and the diameter of the Sun.

Kanali Yantra

Palbha Yantra

Interesting facts 

The monument features instruments operating in each of the three main classical celestial coordinate systems: the horizon zenith local system, the equatorial system and the ecliptic system.

The monument was damaged in the 19th century. Early restoration work was undertaken under the supervision of Major Arthur Garrotte, a keen amateur astronomer.

Jantar Mantar deploys all three ancient coordinate systems of the five celestial coordinate systems known.

Interestingly, the observatory is used by astronomers these days to calculate the auspicious dates for Indian weddings. It is believed that the observatory is the single most collective work of vedic thought that still survives, apart from the Scriptures.


Jantar Mantar is situated in 18,700 square metres of area. It is still in use today, both for teaching and calculation purposes and retains extraordinary accuracy. Some of the instruments still leave the visitors in awe.

Jantar Mantar – Ujjain


Ujjain was the former capital of the Malabar province and is located on the prime meridian established by the ancient Hindu canons of astronomy. The architectural marvel Jantar Mantar at Ujjain, also called the Vedh Shala Observatory established in the 17th century, is the oldest to be constructed among the group of five observatories. Maharaja Sawai Jai Singh took on to its construction in 1719, to help the Hindu scholars and astrologers. The place is a paradise for stargazers.


Hindu astrologers and scholars give great importance to Ujjain. Since the old times, it has been the research centre for Hindu scholars. Some Indian astronomers state that the Tropic of Cancer is supposed to pass through Ujjain, which makes the Jantar Mantar here, a more important observatory.

Architectural style 

This Jantar Mantar has some prominent monuments. They are- 

Shanku Yantra- 

A vertical gnomon (Shanku) is fixed at the centre of the circular platform. The platform is in the horizontal plane. The shadow of the gnomon aids the drawing of seven lines on that plain. According to this, 22nd December is the shortest day of the year, 21st March and 23rd September are the dates having equal days and nights, and 22nd June is the longest day of the year. These lines also represent the zodiac signs. The latitude of Ujjain is represented through the shadow of the gnomon or equinoctial days.

Nadivalaya Yantra-  

This instrument is built in the plane of the celestial equator. It has two parts – northern and southern. The north disc illuminates when the Sun is in the northern hemisphere and vice versa for six months each. The shadow of the peg parallel to the axis of the Earth, fixed at the centre of the disk represents the time of Ujjain.

Samrat Yantra- 

The Supreme Instrument or the Samrat Yantra is 22 feet long instrument, with a staircase at an inclination 23° and 10°. It is the equinoctial sundial. The upper planes of the two walls beside the steps in the middle of this piece are parallel to the Earth’s axis. To the east and west side of the wall, there are two quadrants situated in the plane of the celestial equator. Engraved on the quadrants are hours, minutes and fraction of a minute.

Digyansha Yantra- 

This instrument has a circular wall with a diameter of 32 feet and 10 inches. This instrument is used to find out the altitude and azimuth of any celestial body.

Turiya Yantra- 

To serve this purpose, Turiya Yantra, a sextant type is constructed on the pole which is at the centre of the circular platform. The pointer of the Turiya Yantra which moves along the round graduated disc located on the top of the pole helps to find the azimuth. The suspended thread of the Turiya Yantra gives the altitude on the graduated scale of the quadrant.

Interesting facts 

Although it is smaller than the Jantar Mantar of Jaipur and Delhi, it is the most important as the Masonic instruments are still being utilised to conduct research.

Indian astronomers believe that the prime meridian of longitude (75° 47 ‘E) passes through Ujjain, thus earning it the epithet ‘Greenwich of India’.

After Sawai Jai Singh, the observatory remained isolated and poorly maintained for 200 years, till it was renovated by Madhav Rao Scindia.

Jantar Mantar – Mathura


Mathura has a special place in the Hindu texts and religion. It was the legendary city of Lord Krishna. Maharaja Sawai Jai Singh selected Mathura as one of the places for his five-observatory plan to be constructed in the northern part of the country.


The decision to build multiple observatories at large distances from one another, was in part a quest for accuracy. The sites chosen by Sawai Jai Singh have historical, political and religious significance.

Present conditions 

The Mathura Observatory and the fort in which it was housed were demolished just before 1857. Of the five observatories, all but the Observatory of Mathura still exist. As Carl Sagan said, “The cosmos is all that is or ever was or ever will be. Our feeblest contemplations of the cosmos stir us – there is a tingling in the spine, a catch in the voice, a faint sensation, as if a distant memory, or falling from a height. We know we are approaching the greatest of mysteries.” Visiting these observatories is like life starting all over again.

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