Jantar Mantar

The History of the Stone Astronomical Observatory in India

1. JANTAR MANTARJANTAR MANTAR
Stone Astronomical ObservatoryStone Astronomical Observatory

2. Ancient India made some big Ancient India made some big
advances in science because advances in science because
it was in constant contact with it was in constant contact with
other countries. After the other countries. After the
conquest of the Indus basin by conquest of the Indus basin by
Darius around 520 B.C. India Darius around 520 B.C. India
was thrown wide open to was thrown wide open to
Babylonian influences. Babylonian influences.
Through the Persians, India Through the Persians, India
also came into contact with also came into contact with
Greece. All these contacts Greece. All these contacts
greatly helped India in greatly helped India in
enriching her sciences, enriching her sciences,
particularly astronomy.particularly astronomy.
Darius

3. There is ample evidence to show that There is ample evidence to show that
Aryabhata (499 A.D.) and Varahamihira (6th Aryabhata (499 A.D.) and Varahamihira (6th
century A.D.) were well-acquainted with century A.D.) were well-acquainted with
Greek astronomy. Greek astronomy.
The most celebrated astronomers after The most celebrated astronomers after
Varahamihira were Brahmagupta (b.598 Varahamihira were Brahmagupta (b.598
A.D.), Lalla (8th cent.), Manjula or Munjala A.D.), Lalla (8th cent.), Manjula or Munjala
(10th cent.), Shripati (c.1039 A.D.) and (10th cent.), Shripati (c.1039 A.D.) and
Bhaskaracharya (b.1114 A.D.). Bhaskaracharya (b.1114 A.D.).
In the post-Bhaskara period not much In the post-Bhaskara period not much
original work in astronomy and mathematics original work in astronomy and mathematics
was done in India till modern times.was done in India till modern times.
AryabhataAryabhata
VarahamihiraVarahamihira
BhaskaracharyaBhaskaracharya

4. The Islamic world produced great The Islamic world produced great
mathematician-astronomers:mathematician-astronomers:

Al-Khwarismi (780-850 A.D.)Al-Khwarismi (780-850 A.D.)

Al-Battani (850-929 A.D.) Al-Battani (850-929 A.D.)

Tabit ibn Qurra (836-901 A.D.) Tabit ibn Qurra (836-901 A.D.)

Al-Sufi ( 10th cent.)Al-Sufi ( 10th cent.)

Al-Biruni (973-1848 A.D.)Al-Biruni (973-1848 A.D.)

Omar Khayyam (1048-1124 A.D.) Omar Khayyam (1048-1124 A.D.)

Nasir al-din at-Tusi (1201-1274 A.D.). Nasir al-din at-Tusi (1201-1274 A.D.).
The last one was in- charge of the The last one was in- charge of the
observatory at Maragha in Iran. observatory at Maragha in Iran.
In 1420 A.D., Ulugh Begh, grandson of In 1420 A.D., Ulugh Begh, grandson of
Timur, built an observatory at Samarkand. Timur, built an observatory at Samarkand.
Using very big but high-precision Using very big but high-precision
instruments he prepared a Star catalogue instruments he prepared a Star catalogue
which was much better than that of which was much better than that of
Ptolemy.Ptolemy.
Samarkand
Maragha

5. 
After a long time Sawai Jai Singh II was the After a long time Sawai Jai Singh II was the
man from India who showed the greatest man from India who showed the greatest
interest in Arabic/Persian astronomy. interest in Arabic/Persian astronomy.

He was born in the ruling family of Amber He was born in the ruling family of Amber
in Rajasthan in 1686 A.D., one year after in Rajasthan in 1686 A.D., one year after
Newton published his book Principia. He Newton published his book Principia. He
succeeded to the Amber throne at the age succeeded to the Amber throne at the age
of thirteen.of thirteen.

Later on he was appointed by Mohammad Later on he was appointed by Mohammad
Shah governor of the province of Agra and Shah governor of the province of Agra and
then also of Malwa. From an early age Jai then also of Malwa. From an early age Jai
Singh was very much interested in Singh was very much interested in
astronomical observations and had astronomical observations and had
acquired thorough knowledge of its acquired thorough knowledge of its
principles and rules.principles and rules.

6. 
Jai Singh felt a great urge in reviving the Jai Singh felt a great urge in reviving the
study of astronomy in India. With the aim of study of astronomy in India. With the aim of
preparingpreparing new tables, Jai Singh at first new tables, Jai Singh at first
started with the traditional brass started with the traditional brass
instruments. Realising their inadequacy, he instruments. Realising their inadequacy, he
discarded them in favour of stone and discarded them in favour of stone and
masonry instruments of huge size. masonry instruments of huge size.

For observing the heavens Jai Singh built For observing the heavens Jai Singh built
observatories at five places : observatories at five places : Delhi, Delhi,
Jaipur, Mathura, Ujjain and Jaipur, Mathura, Ujjain and
Varanasi.Varanasi. The first one was built in Delhi The first one was built in Delhi
in year around 1724. These observatories, in year around 1724. These observatories,
which in course of time came to be called which in course of time came to be called
'Jantar Mantar', housed a wide variety of 'Jantar Mantar', housed a wide variety of
masonry and metal instruments. masonry and metal instruments.

7. Jai Singh, making use of the masonry and metal Jai Singh, making use of the masonry and metal
instruments of his observatories, prepared the instruments of his observatories, prepared the
astronomical treatise Zij-I -Muhammad Shah and astronomical treatise Zij-I -Muhammad Shah and
dedicated it to the reigning monarch Muhammad Shah. dedicated it to the reigning monarch Muhammad Shah.
The work was completed around 1727-28 A.D. The work was completed around 1727-28 A.D.
Jai Singh's court astronomer Pt.Jagannatha, who had Jai Singh's court astronomer Pt.Jagannatha, who had
mastered in Arabic and Persian, translated from Arabic mastered in Arabic and Persian, translated from Arabic
into Sanskrit works titled Rekhaganita and Siddhanta-into Sanskrit works titled Rekhaganita and Siddhanta-
Samrata. The translation of the former was completed in Samrata. The translation of the former was completed in
1718 A.D. and of the latter in 1731 A.D.1718 A.D. and of the latter in 1731 A.D.

8. 
Jai Singh had established contacts with Jai Singh had established contacts with
Jesuit missionaries in India and had also Jesuit missionaries in India and had also
known the telescope. But he did not make known the telescope. But he did not make
use of the Copernican revolution ushered use of the Copernican revolution ushered
in Europe. He remained a firm follower of in Europe. He remained a firm follower of
the geocentric system of Indian tradition the geocentric system of Indian tradition
and of Ptolemy. It seems that Jai Singh and of Ptolemy. It seems that Jai Singh
had no knowledge of the works of Kepler had no knowledge of the works of Kepler
(1571-1630) or Newton (1642-1727).(1571-1630) or Newton (1642-1727).

Jai Singh want to determine new Jai Singh want to determine new
planetary constants but his primary planetary constants but his primary
interests in astronomy centered on the interests in astronomy centered on the
moon. He was more interested in moon. He was more interested in
observing and mathematically predicting observing and mathematically predicting
the position of this heavenly body. He was the position of this heavenly body. He was
also interested in the prediction of Solar also interested in the prediction of Solar
eclipses and in calculation of the eclipses and in calculation of the
occultation of stars and planets by the occultation of stars and planets by the
moon.moon.

9. Jai Singh constructed 15 different types of
instruments of masonry for his observatories. Out
of these fifteen he himself invented seven
instruments. According to the precession of the
instruments it can be divide in following
categories:

 Low precision Masonary InstrumentsLow precision Masonary Instruments
 Medium precision Masonary InstrumentsMedium precision Masonary Instruments
 High precision Masonary InstrumentsHigh precision Masonary Instruments

10. Jai Singh Low precision Masonary InstrumentsJai Singh Low precision Masonary Instruments
InstrumentInstrument NumberNumberLocationLocation
DhruvadarsakaDhruvadarsaka 11 JaipurJaipur
NadivalayaNadivalaya 55 Jaipur,Varanasi,Ujjain,Mathura,Jaipur,Varanasi,Ujjain,Mathura,
UjjainUjjain
PalabhaPalabha 22 Jaipur UjjainJaipur Ujjain
AgraAgra 55 Jaipur,Varanasi,Ujjain,Mathura,UjjainJaipur,Varanasi,Ujjain,Mathura,Ujjain
SankuSanku 11 MathuraMathura
Unknown InstrumentUnknown Instrument 11 VaranasiVaranasi

11. Jai singh Medium precision Masonary InstrumentsJai singh Medium precision Masonary Instruments
InstrumentInstrument NumberNumber LocationLocation
JaiPrakasaJaiPrakasa 22 Delhi, JaipurDelhi, Jaipur
Rama YantraRama Yantra 22 Delhi, JaipurDelhi, Jaipur
Rasi ValayaRasi Valaya 1212 JaipurJaipur
Sara YantraSara Yantra 11 JaipurJaipur
DigamsaDigamsa 33 Varanasi,Ujjain,JaipurVaranasi,Ujjain,Jaipur
KapalaKapala 22 JaipurJaipur

12. Jai singh High precision Masonary InstrumentsJai singh High precision Masonary Instruments
InstrumentInstrument NumberNumber LocationLocation
SamratSamrat
66 Delhi,Jaipur(2),Ujjain,Varanasi(2)Delhi,Jaipur(2),Ujjain,Varanasi(2)
SasthamsaSasthamsa
55 Delhi, Jaipur(4)Delhi, Jaipur(4)
Daksinottara BhittiDaksinottara Bhitti
66 Jaipur,Varanasi(2),Ujjain,Mathura,Jaipur,Varanasi(2),Ujjain,Mathura,
DelhiDelhi

13. Instruments added after Jai SinghInstruments added after Jai Singh
InstrumentInstrument NumberNumber LocationLocation
Mishra YantraMishra Yantra 11 DelhiDelhi
Sanku YantraSanku Yantra 11 UjjainUjjain
Horizontal ScaleHorizontal Scale 11 JaipurJaipur

14. Measurements Related TermsMeasurements Related Terms
Azimuth: Azimuth: AzimuthAzimuth is is
generally defined as a generally defined as a
horizontal angle measured horizontal angle measured
clockwise from any fixed clockwise from any fixed
reference plane.In modern reference plane.In modern
astronomy it is nearly astronomy it is nearly
always measured clockwise always measured clockwise
from the north base line or from the north base line or
meridian. It measured in meridian. It measured in
degree and tells about the degree and tells about the
direction of a celestial body direction of a celestial body
from the observer.from the observer.

15. Measurements Related TermsMeasurements Related Terms
Altitude: As a general Altitude: As a general
definition, altitude is a definition, altitude is a
distance measurement, distance measurement,
usually in the vertical or usually in the vertical or
"up" direction, between a "up" direction, between a
reference line and a point reference line and a point
or object. The reference or object. The reference
line also often varies line also often varies
according to the context. according to the context.

16. Measurements Related TermsMeasurements Related Terms

MeridianMeridian : A : A meridianmeridian (or (or line of longitudeline of longitude) is an ) is an
imaginary arc on the Earth's surface from the North Pole to imaginary arc on the Earth's surface from the North Pole to
the South Pole that connects all locations running along it the South Pole that connects all locations running along it
with a given longitude. The position of a point on the with a given longitude. The position of a point on the
meridian is given by the latitude .meridian is given by the latitude .

Zenith Distance:Zenith Distance: In general terms, the In general terms, the zenithzenith is the direction is the direction
pointing directly "above" a particular location . The concept pointing directly "above" a particular location . The concept
of "above" is more specifically defined in astronomy, of "above" is more specifically defined in astronomy,
geophysics as the vertical direction opposite to the force of geophysics as the vertical direction opposite to the force of
gravity at a given location. The opposite direction, i.e. the gravity at a given location. The opposite direction, i.e. the
direction of the gravitational force is called the nadir. The direction of the gravitational force is called the nadir. The
term zenith is also used to represent the highest point term zenith is also used to represent the highest point
reached by a celestial body during its apparent orbit around reached by a celestial body during its apparent orbit around
a given point of observation.a given point of observation.

17. Hour AngleHour Angle: In astronomy, the : In astronomy, the hour anglehour angle is one of the coordinates is one of the coordinates
used in the equatorial coordinate system for describing the position of used in the equatorial coordinate system for describing the position of
a point on the celestial sphere. The hour angle of a point is the angle a point on the celestial sphere. The hour angle of a point is the angle
between the half plane determined by the Earth axis and the zenith between the half plane determined by the Earth axis and the zenith
(half of the meridian plane) and the half plane determined by the (half of the meridian plane) and the half plane determined by the
Earth axis and the given point. The angle is taken with minus sign if Earth axis and the given point. The angle is taken with minus sign if
the point is eastward of the meridian plane and with the plus sign if the point is eastward of the meridian plane and with the plus sign if
the point is westward of the meridian plane the point is westward of the meridian plane
LatitudeLatitude: : LatitudeLatitude, usually denoted by the Greek letter phi (, usually denoted by the Greek letter phi (φφ) gives ) gives
the location of a place on Earth (or other planetary body) north or the location of a place on Earth (or other planetary body) north or
south of the equator. Technically, latitude is an angular measurement south of the equator. Technically, latitude is an angular measurement
in degrees (marked with °) ranging from 0° at the equator (low in degrees (marked with °) ranging from 0° at the equator (low
latitude) to 90° at the poles (90° N or +90° for the North Pole and 90° latitude) to 90° at the poles (90° N or +90° for the North Pole and 90°
S or −90° for the South Pole). S or −90° for the South Pole).

18. EquinoxEquinox : An : An equinoxequinox occurs twice a year, when the tilt of the occurs twice a year, when the tilt of the
Earth's axis is inclined neither away from nor towards the Sun, Earth's axis is inclined neither away from nor towards the Sun,
the Sun being vertically above a point on the Equator. The term the Sun being vertically above a point on the Equator. The term
equinoxequinox can also be used in a broader sense, meaning the date can also be used in a broader sense, meaning the date
when such a passage happens. The name "equinox" is derived when such a passage happens. The name "equinox" is derived
from the Latin from the Latin aequusaequus (equal) and (equal) and noxnox (night), because around (night), because around
the equinox, the night and day are approximately equally long. the equinox, the night and day are approximately equally long.
Ecliptic Ecliptic The The eclipticecliptic is the apparent path that the Sun traces is the apparent path that the Sun traces
out in the sky during the year. As it appears to move in the out in the sky during the year. As it appears to move in the
sky in relation to the stars, the apparent path aligns with the sky in relation to the stars, the apparent path aligns with the
planets throughout the course of the year. More accurately, it planets throughout the course of the year. More accurately, it
is the intersection of a spherical surface, the celestial sphere, is the intersection of a spherical surface, the celestial sphere,
with the with the ecliptic planeecliptic plane..

19. 
Equator :Equator : The The equatorequator (sometimes referred to colloquially as (sometimes referred to colloquially as
"the Line""the Line") is the intersection of the Earth's surface with the ) is the intersection of the Earth's surface with the
plane perpendicular to the Earth's axis of rotation and plane perpendicular to the Earth's axis of rotation and
containing the Earth's center of mass. In simpler language, it containing the Earth's center of mass. In simpler language, it
is an imaginary line on the Earth's surface approximately is an imaginary line on the Earth's surface approximately
equidistant from the North Pole and South Pole that divides equidistant from the North Pole and South Pole that divides
the Earth into a Northern Hemisphere and a Southern the Earth into a Northern Hemisphere and a Southern
Hemisphere. Hemisphere.

Angle of Declination: Angle of Declination: Angle at a particular point on the Earth's Angle at a particular point on the Earth's
surface between the direction of the true or geographic North surface between the direction of the true or geographic North
Pole and the magnetic north pole. The angle of declination Pole and the magnetic north pole. The angle of declination
has varied over time because of the slow drift in the position has varied over time because of the slow drift in the position
of the magnetic north pole.of the magnetic north pole.

20. JANTAR MANTAR DELHI

21. Mishra YantraMishra Yantra
Samarat Gnomon
Quadrant
Second
Quadrant
Samarat Gnomon
Niyata Cakra

22. Mishra YantraMishra Yantra
Mishra Yantra consists of several instruments within the single Mishra Yantra consists of several instruments within the single
structure. The instruments included in the structure are as structure. The instruments included in the structure are as
followsfollows::
1.Daksinottra Bhitti1.Daksinottra Bhitti : for measuring the zenith distance or : for measuring the zenith distance or
altitude of sun and other planets.altitude of sun and other planets.
2.Karkarasi Valaya::2.Karkarasi Valaya:: Instrument is now in ruins. Application is Instrument is now in ruins. Application is
not known and according to the theory it was used to measure not known and according to the theory it was used to measure
directly the longitude of celestial body.directly the longitude of celestial body.
3.Samarat Yantra3.Samarat Yantra : for measuring the local time. : for measuring the local time.
4. Niyata Cakras:4. Niyata Cakras: for measuring the declination of an object at for measuring the declination of an object at
interval of a few hours as the object travels from east to west in interval of a few hours as the object travels from east to west in
the sky.the sky.
5. Quadrant arc5. Quadrant arc of unknown function of unknown function

23. Samarat YantraSamarat Yantra

24. Samarat YantraSamarat Yantra

The primary object of Samarat is to indicate the solar The primary object of Samarat is to indicate the solar
time or local time of a place.time or local time of a place.

By knowing the time of the meridian transit of By knowing the time of the meridian transit of
prominent star and observing the hour angle of the prominent star and observing the hour angle of the
star or its angular distance from meridian time at star or its angular distance from meridian time at
night may also calculated from this instrument.night may also calculated from this instrument.

In addition to marking local time the Samarat Yantra In addition to marking local time the Samarat Yantra
was used to determine the sun declination and the was used to determine the sun declination and the
right ascension of any celestial object.right ascension of any celestial object.

25. Jai Prakesh YantraJai Prakesh Yantra

26. Jai Prakash YantraJai Prakash Yantra

Twin hemispherical bowls of Jai Prakas yantra are each a Twin hemispherical bowls of Jai Prakas yantra are each a
reflection of the sky above. The bowls are marked in sectors reflection of the sky above. The bowls are marked in sectors
and gaps. Observers move inside the gap regions and make and gaps. Observers move inside the gap regions and make
observations using the markings on the sectors. The observations using the markings on the sectors. The
instruments are complimentary, in the sense that where there is instruments are complimentary, in the sense that where there is
a gap in one of the bowl, is a sector placed in the other bowl a gap in one of the bowl, is a sector placed in the other bowl
and vice versa. Spliced together, they make a whole bowl that and vice versa. Spliced together, they make a whole bowl that
is a complete reflection of the sky above. is a complete reflection of the sky above.
Cross wires are stretched in the North-South and East-West Cross wires are stretched in the North-South and East-West
direction on the surface of the instrument bowls. Shadow of the direction on the surface of the instrument bowls. Shadow of the
centre of this cross wire, on the surface of the bowl, shows the centre of this cross wire, on the surface of the bowl, shows the
position of the Sun in the sky. position of the Sun in the sky.
The instrument can measure the local co-ordinates of a The instrument can measure the local co-ordinates of a
celestial object - the Altitude and Azimuth. celestial object - the Altitude and Azimuth.

27. Rama YantraRama Yantra

28. Jantar MantarJantar Mantar
JaipurJaipur

29. Jaipur, Jantar Mantar was the second and more sophisticated Jaipur, Jantar Mantar was the second and more sophisticated
observatory Jai singh built.The instruments were so big and observatory Jai singh built.The instruments were so big and
accurate ,as they were built of stone,masonry and marble. accurate ,as they were built of stone,masonry and marble.
There are 18 instruments in the Jaipur observatory. He There are 18 instruments in the Jaipur observatory. He
procured latest astronomical books and instruments from procured latest astronomical books and instruments from
Europe.Some he had translated in Sanskrit.Some of these Europe.Some he had translated in Sanskrit.Some of these
translated texts are on display in the City Palace Museum. translated texts are on display in the City Palace Museum.

30. Samrat YantraSamrat Yantra
By far the biggest yantra in Jantar Mantar. it is a huge Sun By far the biggest yantra in Jantar Mantar. it is a huge Sun
Dial. It is 89 feet high and 148 feet wide. It can measure Dial. It is 89 feet high and 148 feet wide. It can measure
local time correctly up to 2 seconds..local time correctly up to 2 seconds..

31. Chakra YantraChakra Yantra

32. The Jaipur observatory has two unit of Cakra Yantra. The Jaipur observatory has two unit of Cakra Yantra.
Instrument is made of heavy molded brass and pivoted to Instrument is made of heavy molded brass and pivoted to
rotate freely about a diameter parallel to the earth axis. rotate freely about a diameter parallel to the earth axis.
Objective of the instrument is to measure the declination Objective of the instrument is to measure the declination
and hour angle of celestial body.and hour angle of celestial body.
For measuring the declination and hour angle of an object, For measuring the declination and hour angle of an object,
a sighting tube is mounted at the centre of the instrument. a sighting tube is mounted at the centre of the instrument.
The tube with a pointer attached to it, rotates about a The tube with a pointer attached to it, rotates about a
perpendicular axis passing through the centre of cakra perpendicular axis passing through the centre of cakra
ring. The observer rotating the cakra about its polar axis ring. The observer rotating the cakra about its polar axis
and the tube about the centre obtains the object in sight and the tube about the centre obtains the object in sight
and the hour angle off the plate at the post. and the hour angle off the plate at the post.

33. Rashivalaya YantraRashivalaya Yantra

34. The Rasivalaya are a set of 12 instruments based on the The Rasivalaya are a set of 12 instruments based on the
principle of samarat yantra are designed for directly principle of samarat yantra are designed for directly
measuring the latitude and longitude of a celestial object.measuring the latitude and longitude of a celestial object.
Rasivalaya were also invented by Jai Singh. A particular Rasivalaya were also invented by Jai Singh. A particular
Rasivalaya instrument become operative when first point Rasivalaya instrument become operative when first point
of sign of the zodiac it represents approaches the of sign of the zodiac it represents approaches the
meridian.meridian.
At that moment its gnomon point towards the pole of At that moment its gnomon point towards the pole of
ecliptic and its guardant become parallel to the ecliptic. ecliptic and its guardant become parallel to the ecliptic.
There are 12 signs of the zodiac, so there are 12 There are 12 signs of the zodiac, so there are 12
Rasivalayas representing each sign.Rasivalayas representing each sign.

35. Narivalaya YantraNarivalaya Yantra

36. This is an effective tool for demonstrating the This is an effective tool for demonstrating the
passage of sun across the celestial equator.passage of sun across the celestial equator.
On the vernal equinox and the autumnal equinox On the vernal equinox and the autumnal equinox
the rays of the sun fall parallel to two opposing the rays of the sun fall parallel to two opposing
faces of plates and illuminate them both. Other faces of plates and illuminate them both. Other
time only one or other face remains in the sun.time only one or other face remains in the sun.
After the sun has crossed the equator around 21 After the sun has crossed the equator around 21
March its illuminate the northern face for sixth March its illuminate the northern face for sixth
months. After 21 September it is the southern months. After 21 September it is the southern
face that receives the rays of the sun for the next face that receives the rays of the sun for the next
six months.six months.
 Jai Singh built Nadivalays at each his Jai Singh built Nadivalays at each his
observatory site except Delhi.observatory site except Delhi.

37. Yantra RajYantra Raj

Great astrolabe is suspended Great astrolabe is suspended
from massive wooden beam from massive wooden beam
supported by tall pillars.supported by tall pillars.

Orientation of the pillars is Orientation of the pillars is
such that the line joining them such that the line joining them
makes an angle of about 23 makes an angle of about 23
degree with the plane of degree with the plane of
meridian.meridian.

This is the largest instrument This is the largest instrument
in the world for its kind. in the world for its kind.
Instrument is built for the Instrument is built for the
latitude of Jaipur as there are latitude of Jaipur as there are
27 degree making between the 27 degree making between the
zenith and the pole.zenith and the pole.

The main function of the The main function of the
instrument is to measure time.instrument is to measure time.

38. Krantiwrita YantraKrantiwrita Yantra
This is the unfinished structure and has two This is the unfinished structure and has two
circular plates. Both the plates have a scale circular plates. Both the plates have a scale
which is divide in degrees.which is divide in degrees.

39. Unnatasha YantraUnnatasha Yantra

40. Unnatamsa can measure the Altitude of a celestial object.
The large graduated brass circle hung from the supporting
beam, is the measuring instrument of the Unnatamsa. The brass
circle is pivoted to rotate freely around a vertical axis. The ring has
two cross beams in the vertical and horizontal directions. A
sighting tube is pivoted at the centre of the circle, which can be
moved in the vertical direction, to align towards any celestial
object.
The rim of the brass circle has graduations marked in such a
way that smallest division is a tenth of a degree. The larger
divisions of 1 degree and of 6 degrees are also marked on the
circle. After sighting the celestial object, its Altitude can be read
from the position of the pointer.

41. Dakshinodak Bhitti YantraDakshinodak Bhitti Yantra

42. Daksinottara BittiDaksinottara Bitti
Daksinottara Bitti yantra consists of a Daksinottara Bitti yantra consists of a
graduated quadrant or a semicircle inscribed graduated quadrant or a semicircle inscribed
on a north-south wall. At the centre of the are on a north-south wall. At the centre of the are
is a horizontal rod. The instrument is used for is a horizontal rod. The instrument is used for
measuring the meridian attitude or the zenith measuring the meridian attitude or the zenith
distance of an object such as the sun, the moon distance of an object such as the sun, the moon
or a planet.or a planet.

43. Jai Prakash YantraJai Prakash Yantra

44. Kapala YantraKapala Yantra

45. The Kapala are built as two hemispherical units, each The Kapala are built as two hemispherical units, each
hemisphere being a complete reflection of the sky hemisphere being a complete reflection of the sky
overhead. overhead.
The western Kapala unit is built for observations while The western Kapala unit is built for observations while
the eastern segment is meant for theoretical the eastern segment is meant for theoretical
conversions of co-ordinates from one system to conversions of co-ordinates from one system to
another. The western Kapala unit is analogous to the another. The western Kapala unit is analogous to the
Jaiprakas – a hemispherical bowl on which every Jaiprakas – a hemispherical bowl on which every
point is a reflection of a point in the sky. point is a reflection of a point in the sky.
By looking at the shadow of a cross wire stretched By looking at the shadow of a cross wire stretched
over its surface, the co-ordinates of the Sun in the over its surface, the co-ordinates of the Sun in the
sky, can be determined with the western Kapalasky, can be determined with the western Kapala. .

46. The yantra hare a diameter of 3.46 m each and are so named
because by there resemblance to the brain cover of human skill.
Jai Praksa and the Kapala are both multipurpose instruments
consisting of hemispherical surface of concave shape and
inscribed width of number of arcs.
These arcs indicate the local time and they measure
astronomical parameter,such as co-ordinates of celestial body.
One difference between the two instruments is that Kapala
indicates the a ppp while Jay Praksa observe the sign of meridian.
Another is that Jay Praksa built in two complementary halves,

47. Ram YantraRam Yantra

48. The Rama yantra, probably named after Rama Singh The Rama yantra, probably named after Rama Singh
The grandfather of Jai Singh.The grandfather of Jai Singh.
This yantra is used to measure the azimuth and altitude This yantra is used to measure the azimuth and altitude
of a celestial object, for example sun.of a celestial object, for example sun.
Cylindrical structure of Rama Yantra is open at the top Cylindrical structure of Rama Yantra is open at the top
and its height equals its radius. and its height equals its radius.
For measuring the azimuth, circular scales with their For measuring the azimuth, circular scales with their
centre at the axis of cylindrical walls. The scales are centre at the axis of cylindrical walls. The scales are
divided into degree and minutes.divided into degree and minutes.
In day time the coordinates of a sun are determined by In day time the coordinates of a sun are determined by
observing the shadow of the pillar top end on the scales.observing the shadow of the pillar top end on the scales.
The coordinates of the moon when it is bright enough to The coordinates of the moon when it is bright enough to
cast a shadow, may also be read in a similar manner.cast a shadow, may also be read in a similar manner.

49. JANTAR MANTAR UJJAINJANTAR MANTAR UJJAIN

50. Daksinottara BittiDaksinottara Bitti

51. Daksinottara BittiDaksinottara Bitti
Daksinottara Bitti yantra consists of a Daksinottara Bitti yantra consists of a
graduated quadrant or a semicircle inscribed graduated quadrant or a semicircle inscribed
on a north-south wall. At the centre of the are on a north-south wall. At the centre of the are
is a horizontal rod. The instrument is used for is a horizontal rod. The instrument is used for
measuring the meridian attitude or the zenith measuring the meridian attitude or the zenith
distance of an object such as the sun, the moon distance of an object such as the sun, the moon
or a planet. or a planet.

52. Samarat YantraSamarat Yantra

53. SANKU
DIGAMASA

54. Digmasa YantraDigmasa Yantra

This consists of two cylindrical wall surrounding a centre This consists of two cylindrical wall surrounding a centre
pillar measure the angle of azimuth of a celestial body. pillar measure the angle of azimuth of a celestial body.

Its centre pillar as well as its wall are engraved in degrees and Its centre pillar as well as its wall are engraved in degrees and
numbers at their top level. numbers at their top level.

Cross wires are stretched between the coordinal points marked Cross wires are stretched between the coordinal points marked
over the outer wall. The observer uses one or more strings over the outer wall. The observer uses one or more strings
with one end tied to a knob on the pillar and other end to stone with one end tied to a knob on the pillar and other end to stone
pebbles suspended over the walls, with these strings the pebbles suspended over the walls, with these strings the
observer defines a vertical plane contain the cross wire and the observer defines a vertical plane contain the cross wire and the
object in the sky. The angular distance of the vertical plane object in the sky. The angular distance of the vertical plane
from the north point, read on the scales indicate the azimuth of from the north point, read on the scales indicate the azimuth of
body.body.

55. Jantar Mantar at VaranasiJantar Mantar at Varanasi

56. Some Glimpses of Jantar Mantar Varanasi

57. Some Glimpses of Jantar Mantar Varanasi

58. Jantar Mantar at VaranasiJantar Mantar at Varanasi
Observatory at Vanarasi has following Instruments:Observatory at Vanarasi has following Instruments:
Samarat YantraSamarat Yantra
DigamsaDigamsa
NadivalayaNadivalaya
Cakra YantraCakra Yantra
Daksinottara BhittiDaksinottara Bhitti
 Unidentified structureUnidentified structure

59. SMRAT YANTRA -------->
<------ DIGAMSA YANTRA

60. <----- Nadivalaya Yantra
Samarat Yantra ---------->

61. Jantar Mantar MathuraJantar Mantar Mathura
The Observatory was built within the local fort on the banks of the
river Yamuna

62. 
It is believed that the observatory at Mathura It is believed that the observatory at Mathura
disappeared about 1850 a few years before the disappeared about 1850 a few years before the
unsuccessful uprising of 1857 against the unsuccessful uprising of 1857 against the
British. British.

At Mathura there were following instruments:At Mathura there were following instruments:
• NadivalayaNadivalaya
• Agra YantraAgra Yantra
• SankuSanku
• Daksinottara BittiDaksinottara Bitti

63. In spite of his best efforts for the revival of In spite of his best efforts for the revival of
astronomical studies in India, Jaya Singh astronomical studies in India, Jaya Singh
remained firmly attached to the medieval remained firmly attached to the medieval
tradition. He died in 1743 A.D., exactly tradition. He died in 1743 A.D., exactly
two hundred years after Copernicus two hundred years after Copernicus
(1473-1543). Today Jaya Singh's work is (1473-1543). Today Jaya Singh's work is
only a tradition and his observatories are only a tradition and his observatories are
nothing but archaeological remains.nothing but archaeological remains.

64. THANKSTHANKS
Prepared By:Prepared By:
Sandipan DharSandipan Dhar