About 230km sowtheast of Delhi, Western India
Inscribed on the UNESCO World Heritage List in 2010


Astronomical Observatory

The Rajput tribal kingdoms in western India were subjugated by the Mughal Empire, based in Delhi. They served the Islamic empire but were able to keep up their own half-independent native states, still embracing Hinduism.
The intelligent Maharaja of Jaipur, Jai Singh II, being able to understand Sanskrit and Persian, had a passion for science, devoting himself particularly to astronomy and astrology. He collected and studied not only Indian but also Persian and European books on the subjects, and in order to make astronomical observation much more precise, he constructed observation apparatuses, enlarging them up to from the laboratory an architectural scale.

Sawai Jai Singh II acceded to the throne, the Maharaja of Amber, at the age of only 13. When he was 20 years old, the sixth Mughal Emperor Aurangzeb died, and the emperorfs sons fought with each other for succession to the throne. Since Jai Singh was on the losing side, his relationship with the Mughal dynasty deteriorated, yet the following emperors changed one after another. He formed a friendship with the 12th Emperor Muhammad Shah (r.1719-48), being appointed the governor of the city of Agra at the age of 33, and the governor of the Malwa region at the age of 35. When he was 41 years old, in 1727, he constructed a new city in the plains, Jaipur, and moved there from mountainous Amber, becoming the Maharaja of Jaipur.

In the meanwhile, Jai Singh, who had devoted himself to astronomy, was requested by the Mughal Emperor Muhammad Shah to make accurate astronomical coordinates and a calendar. He first constructed an observatory in Delhi, and then similar ones in Varanasi, Ujjain, Mathura, and lastly the largest one in his own city Jaipur as the synthesis of them.

The large observation instruments, called Yantras, were not designed@ in traditional architectural forms, whether Hindu or Islamic, but designed with pure geometry and curves, without any decorations. Since they were based on functions completely different from palaces or temples, when seen as buildings, their forms are amazing and very mysterious with unexpected shapes, reminding us of expressionist architecture in the 20th century or Russian constructivist styles. Besides that, they would bring up in our minds the fantastic works by the evisionary architectsf at the age of the French Revolution, Etienne-Louis Boullée (1728-99) or Claude-Nicolas Ledoux (1736-1806).

Maharaja of Jaipur, Sawai Jai Singh (1686-1743)
(From "The Astronomical Observatories of Jai Singh"
by G.R. Kaye, 1918, Calcutta)

The designation eJantar Mantarf is a corruption of Yantra (instrument) plus Mantra (true words, conjuration) in Sanskrit, used for the Delhi Observatory at the beginning. Later it came to also indicate the other observatories established by Jai Singh.

The enactment of the calendar, which would be in common currency anywhere in the state, was an important work of the ruler of government for not only administration but also religious ceremonies, calculation and levy of tax. For the enactment, the accurate measurement of the sun and moonfs movement and their time and fixing the place of the standard point for that were needed.
However, as ancient and medieval astronomy was indivisibly related with astrology, it was full of religious prejudice. The realization of scientific astronomy had to wait until the development of the Modern West by Galileo, Kepler and Newton.

Nevertheless, there had been monarchs in various states since ancient times who were absorbed in astronomy or astrology, some of whom wished to materialize facilities in an architectural scale. While there would have been some realizations in ancient Egyptian culture, it is well known that the ancient Mayan civilization highly developed astronomy, though there is no relation between it and India in this article. There remains a symbolic building from the 10th century, assumed to have been an astronomical observatory, at Chichen Itza, Mexico.

Mayan Observatory at Chichen Itza, Mexico, 10c.

In the Islamic world, huge observation instruments might have been built from old times, in Baghdad, Isfahan, Cairo, Istanbul, and so on. The most famous observatories among them were in Maragheh, Iran, in the 13th century and in Samarkand, Uzbekistan, in the 15th century. Astronomy was much more advanced in the Islamic sphere than in Europe in those days.
In contrast with the Maragheh Observatory, constructed by the astronomer Nasil al-Din (1201-74) under the command of the first monarch of the Il Khanids in Mongol Empire, Hulagu Khan (r. 1256-65), of which nothing is left now, Ulugh Begfs Observatory in Samarkand was excavated, and its underground part is preserved. The lost aboveground part was restored in a drawing.

Ulugh Beg (1394-1449), the fourth monarch of the Timurid dynasty (r. 1447-49), compiled the eZigef (Ulugh Begfs astronomical table) based on observations through many years at the Samarkand Observatory, which was brought to Europe and eagerly studied. However, after he was assassinated in 1449 by one of his sons during the conflict over the succession to the throne, most of the observation implements were wrecked, and no one took over the work of Ulugh Beg in the Islamic world.
It is recorded that when Babur, the founder of the Mughal dynasty in India, visited Samarkand in 1497, Ulugh Begfs Observatory still existed. This is the direct ancestor of our Jai Singhfs Observatory in Jaipur, India.

The Ulugh Beg Observatory in Samarkand, Uzbekistan, c.1420

Presently Europe entered the Renaissance, making rapid development in astronomy. In India, it was Sawai Jai Singh, the Hindu maharaja of Jaipur in the 18th century, who constructed a series of collective observatories in several places in India, deeply studying Islamic traditional astronomy as well as new materials brought from Europe. Among classical Hindu literature, there were two Sanskrit treatises on astronomy: gSurya Siddhantah by Varahamihira and gBrahma Siddhantah by Brahmagupta.

Jai Singh and his assistant (or more precisely his teacher), Jagannath, finding many mistakes in these treatises, improved observation instruments and enlarged them greatly to get more precise observation values for the true calendar to correctly determine the dates of Hindu festivals. Jagannath wrote a new treatise on astronomy gSamrat Siddhantah in Sanskrit.

Jai Singh possibly had shown a small-scale trial observatory to the Mughal emperor Muhammad Shah, who asked Jai Singh to construct a large-scale observatory in Delhi to produce an accurate table of constellations and calendar. Construction began in 1719 and was completed in 1724. Based on the data recorded here, Jai Singh, in collaboration with Jagannath, improved gUlugh Begfs Astronomical Tableh and drew up gZij Muhammad Shahih (Muhammad Shahfs Astronomical Table) to dedicate to the emperor.

Subsequently, Jai Singh erected similar observatories also in Varanasi, Ujjain and Mathura, the last of which was unfortunately demolished in the 19th century, leaving nothing behind for us. At the very end, synthesizing all those facilities and experiences, he constructed the great astronomical observatory (Jantar Mantar) of the largest scale at the palace district of his own state, Jaipur.

A portable Astrolabe (Astro Calculator)

The most important instrument from a practical aspect was a portable eAstrolabef as they were called, which was utilized for various purposes: to observe the celestial sphere, calculate longitude, latitude and time, and refer to the table of constellations. Its origin was in ancient Greece, but it is said to have been put to practical use in around the 9th century in the Middle East. There still exists many of them in Jaipur and the hugest two, made of iron and brass respectively, are suspended from a wooden beam in the Jaipur Observatory, named eYantra Rajf. Their actual use might have been for astrology.

What is most architecturally conspicuous in observatories is the enormous eSamrat Yantraf. It is always the highest and largest instrument in each observatory in a shape of a right triangle. The largest one, in Jaipur, reaches 27.5 meters in height, with flight of stairs on its hypotenuse. When going up to the top, one can look out over both the whole precincts and its Yantras (instruments) in one view.

Most Yantras in every Jantar Mantar are as large as actual buildings, but they do not use any elements or ornaments of traditional styles of either Hindu temples or Muslim mosques, being thoroughly composed of pure geometric shapes. The great Samrat Yantra in Jaipur is only surmounted with a traditional element, Chhatri, which was used as a watching room for weather forecasts or the advent of monsoon seasons. Only the persons holding those roles could climb, the stairway was controlled with a door at the entrance usually locked. The Brihat Samrat Yantra is a giant equatorial sundial; the hypotenuse of its right triangle casts a shadow on the western arc of the circle in the morning and on the eastern in the afternoon, indicating the exact time on their scales.

Brihat Samrât Yantra (Giant Equatorial Sundial) in Jaipur
Plan of the Brihat Samrât Yantra in Jaipur Observatory
(From "Cosmic Architecture in India" by Andreas Volwahsen, 2001, Prestel)
Both wings have a continuous three-dimensional curved surface.

In the period when those Jantar Mantars were constructed, as the European astronomy had developed much further, they now do not have such great significance in scientific history from the view point of invention and discovery. However, their sizes of architectural scale and their figures being far apart from usual traditional Indian and Islamic architecture, they rather remind one of Expressionist architects in Modernism such as Erich Mendelsohn (1887-1953) and Bruno Taut (1880-1938), attracting strong attention from contemporary architects. Now we will see the astronomical observatories in India made by Sawai Jai Sing II, one by one.

Delhi Observatory, 1724

The Delhi Observatory, the first actualized one, was built at the request of the Mughal Emperor Muhammad Shah, but its site is said to have been Sawai Jai Singhfs own land. It was constructed from 1719, when he was designated as the governor of Agra, to 1724, as an established theory says, though with some uncertainty. It is difficult to know the accurate years of construction of every observatory of Jai Singh.

Although Sawai Jai Singh made observation instruments in Delhi following antique documents at the outset, having unsatisfactory results, he is said to have remade all of them in his own design. However, as the most peculiar-shaped attractive Mishra Yantra was constructed after his death, it might have been the work of his son, Madhu Singh. It is also said that Madhu lacked passion for astronomy, so he might have employed a talented architect.

When G.R. Kaye surveyed the Delhi Observatory for the Archeological Survey of India in 1931 at the end of the British rule, it was on a deserted land with almost nothing around it. After the new capital New Delhi was constructed in 1931, the observatory came to be incorporated in it, and has now formed an archeological park surrounded by high-rise buildings.
Le Corbusier visited this Jantar Mantar in Delhi on every occasion he came to India for the work of Chandigarh, sometimes sketching it. He might have been attracted by its geometric formation.

Site plan or the Delhi Observatory and current state of the park
(From "The Astronomical Observatories of Jai Singh" by G.R. Kaye, 1918)
(From "Cosmic Architecture in India" by Andreas Volwahsen, 2001)

Brihat Samrat Yantra & Jai Prakash Yantra
Ram Yantra & Jai Prakash Yantra
Magical Mishra Yantra

Varanasi Observatory, 1737

Among the banks of the Ganges River in Varanasi (Benares), just on the north of famous Dashaswamedh Ghat (riverbank platforms with steps) is Manmandir Ghat, over which stands the Manmandir Palace from the early 17th century, overlooking the great river. This was the detached palace of Jaipur state, built by Raja Man Singh, the maharaja five generations before Sawai Jai Singh, who also constructed an astronomical observatory on the roof of this palace after Delhi. Though it is smaller in scale due to its location, Jai Singh might have preferably selected this place because of the observation instruments being able to get horizontal sun beams without any obstruction.

Site plan of the Varanasi Observatory
(From "A Guide to the Observatories" by G.R. Kaye, 1920, Calcutta)

An etching of the Varanasi Observatory by A. Campbell, 1773
(From "Cosmic Architecture in India" 2001,Prestel)
Clearly showing it was built on the roof of Man Mandil Palace

G.R. Kaye wrote its construction year as 1737 in his report, which has become established theory, but Andreas Volwahsen convincingly conjectures it was instead in 1710. Given that Jai Singh first erected this observatory with a modest scale and then the Mughal emperor, hearing this, asked him to construct a much larger one in Delhi to make an astronomical table and calendar, that date is consistent, for it is a little incomprehensible that the Muslim emperor had a young Hindu prince, without a track record, build a large observatory in his capital out of the blue.

If accepting Kayefs established 1737 theory, this Varanasi Observatory turns out to be the last one, while G. Tillotson insists that this is the third one during almost the same period of 1724-34 as those of Mathura and Ujjain. In short, the construction date of every Jantar Mantar is imprecise.

Varanasi Observatory (Jantar Mantar)

Ujjain Observatory, c.1730

Ujjain had been eIndian Greenwichf since ancient times, where Hindu astronomers (astrologers) postulated the position of the prime meridian. This was mentioned in the 3rd century Sanskrit treatise gSurya Siddhantah or Varahamihirafs gPancha Siddantikah in the 6th century. Jai Singh erected a Jantar Mantar in this town, probably because he was respectful of such traditional importance. Its exact construction date is not clear, despite being assumed that it was after he was appointed as the governor of Malwa in west-central India by the emperor Muhammad Shah.
When G.R. Kaye researched the Ujjain Observatory in 1915, it was considerably devastated, but now it has been carefully restored by the Archeological Survey of India.

Site plan of the Ujjain Observatory
(From "A Guide to the Observatories" by G.R. Kaye,1920, Calcutta)

Ujjain Observatory (Jantar Mantar)

Mathura Observatory, c.1738

Jai Singh II constructed his fifth observatory in Mathura, on top of Kans Qila Fort that had also been erected by his ancestor, Raja Man Singh at the end of the 16th century. However, the fort was sold off slightly before the Indian Mutiny (1857-8), at the same time, the observatory was dismantled to use as construction materials without leaving any traces.
Tiefenthaler, a Jesuitical missionary who had visited the Mathura Observatory, wrote that it was a miniature version of the Jaipur Observatory, and in contrast to the Jaipur located in the plains, the staff there were able to observe stars on horizontal lines both at sunrise and sunset from Mathurafs observatory on the mountain.

Mathurafs observatory is said to have been built circa 1738, though not confirmed. According to Z.M. Shahi, the order of construction was Jaipur, Mathura, Ujjain, and Varanasi for the purpose of verifying the data recorded at Delhi Observatory, though similarly not a few scholars consider Jaipurfs one to be the second, probably because its inaugural date of construction was early.

Jaipur Observatory, 1734

The capital of current Rajasthan State, Jaipur was a planned city in the 18th century. The Maharaja of an illustrious Rajput family based on the mountain fort of Amber, Sawai Jai Singh II (1686-1743) constructed a new city in 1727 in the plains, 11km south of Amber, designating it Jaipur from his own name. The new city was made by uniting Indian traditional thought in accordance with old Sanskrit documents and Islamic geometric constitution like eChahar Bagh (quartered garden) actualized in Mughal palace districts in Delhi or Fatehpur Sikri, becoming the most notable city-planning in the history of India.

The town consists of nine quarters of 800 meters square each, the center of which is the palace quarter. This orderly city with a grid pattern of roads intersecting at right angles resembles 20th century modernist city-planning. Since most buildings along the main streets are colored in pink, it has a sobriquet of ePink Cityf. It has developed southward nowadays, being full of energy as the state capital. The unique astronomical observatory (Jantar Mantar) of the largest scale was constructed in the palace quarter near palace buildings of Mughal and Indo-Saracenic styles.

City plan of Jaipur with a grid pattern, 1727
The city axis has a gap of c.15 degrees from the north-south line.
The red spot in the palace quarter indicates the Jantar Mantar.

In G.R. Kayef book, the Jaipur Jantar Mantar is written to have been built circa 1734, which has been established, while G. Tillotson and others insist that it had been commenced to have been built 10 years earlier than that, about 1718. If so, the shape of its site would not have followed the city-axis of the later city-planning but have naturally followed the north-south axis, so it is more natural to think that the observatory would have commenced to be erected after the construction of the city.
All the instruments for observation were designed by Jai Singh II, among which 13 were made of stone and the other 3 metal, all of which are extant and intact in situ. His collection of books and his documents are preserved in the Museum of Maharaja Sawai Man Singh II.

Jai Singh invited a Goan Jesuit, Don Pedro de Syrva Leitao (c.1766-?) who was a man of discernment regarding astronomy, to hear critical opinions and information from Europeans. Pedro came to Jaipur in 1731 and stayed there 60 years till his death. Was it because of his admiration of the Jantar Mantar? Since his colleagues might have joined him in 1740, it might have been pleasant to live under such an intelligent monarch.
However, Newton, Kepler and Galileo were all regarded as heretical for the Catholic church, Jai Singh could not have gained the knowledge of the Western frontier science of astronomy.
In addition, the drawings of each instrument of the Jantar Mantars have not been left to us, but in Jaipur, miniature models of many instruments were discovered, though it is not known if they were made before the construction or in later periods.

Site plan of the Jaipur Observatory
    General views of the Jaipur Observatory
Elevation of the Brihat Samrât Yantra
(From "Cosmic Architecture in India" by Andreas Volwahsen, 2001)
The right triangle is 24 m in height, c. 44 m on base, and c. 50 m on hypotenuse.
Western side of Jaipur & Rashi Valâya Yantras
Nari Valâya Yantra & Chakra Yantra
Unnatansha Yantra & Rashi Valâya Yantras
Jai Prakâsh Yantra & Kapâla

As a conclusion, I quote here a part written on Jai Singhfs Jantar Mantars from Henri Stierlinfs gArchitecture de lfIslamh that I have translated once into Japanese for publishing 30 years ago:

The essential interest in Jaipur resides, other than in its rich palaces, in an extraordinary astronomical observatory constructed remarkably at the center of the palace quarter. Jai Singh II, being passionate for science, had them constructed in Delhi, Mathura, Ujjain, Varanasi, as well as in Jaipur as gigantic instruments to measure celestial stars, modelled on those constructed by Ulugh Beg in Samarkand three centuries earlier. Thus, these architectural creations for scientific purposes, which was awakening in India, was a remote descendant of the Timurid art, and inscribed itself to the pedigree of Islamic works.

The Jaipur Observatory, constructed from 1728 to 1733, is probably the most complete among the series of astronomical realizations in India. It includes a huge triangle gnomon (sundial) of 30 meters in height, sighting devices (rachis) to measure the courses of various celestial objects, underground structures with adits for astronomers, and so on.

The purpose of these buildings was to actualize the highly accurate astronomical observation by enlarging the usual outfit of instruments to some hundred times grander. It resulted in creating an astonishing architecture with surrealistic aspects. Their pure geometric and functional forms (circles, cylinders, hemispheric hollows, triangles, semi-circular arcs on the ecliptic plain, etc.) brought forth a work of extremely modern character.

Thus, uniting Mughal forms and techniques with astronomical requirements, Indo-Islamic art engendered an extraordinary creation as a hymn of science, for enjoyment of a cultivated Hindu maharaja who lived in the age of the Enlightenment.

For people who would like to know more minutely about Jai Singh's
astronomical observtories, I will introduce three beneficial books here.


[ Archaeological Survey of India, New Imperial Series 40.]
Written by George Rusby Kaye, published 100 years ago
by Government of India, Calcutta, 1918,
a large book of 32 x 25 x 2.4cm -210pp.

George Rusby Kaye (1866-1929) researched all of Jai Sing IIfs astronomical observatories and published this book as one of the series of reports of the A.S.I. (Archeological Survey of India) of crown rule in India (Indian Empire). The descriptions are quite detailed with a plan of each observatory and folded map of the city of Ujjain. The copy I gained had been so damaged that the antique bookshop repaired it, rebinding it in half leather.



Written by G.R. Kaye, 1920, Superintendent Government Printing,
Calcutta, a croth bound small book of 21 x 14.2 x 1.6cm - 140pp.

A convenient book on Jai Singh's Astronomical Observatories (Jantar Mantars) for general readers. It is a reduced and summarized edition of the above-shown book, published two years later by the same author. With plans, drawings and photos (though not many) as well as concisely arranged descriptions, it is a very useful book on this subject for amateurs.


Writtten by Andreas Volwahsen, 2001, Prestel, Munich,
London, New York, Mapin Publishing, Ahmedabad,
a large book of 30.5 x 24.5 x 1.8cm ° 160pp.

80 years after G.R. Kaye, Andreas Volwahsen deeply studied Jai Singhfs Jantar Mantars and published this book as one of a trilogy on Indian architecture, synthesizing later studies and making new drawings. This is a splendid book full of fine color photographs, which also draw comparisons and describes influential relations with predecessors of astronomies in the globe.


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