8SCIENCE REPORTER, AUGUST 2011

Cover S

tory

FROM astronomy to medicine and

from metallurgy to mathematics,

ancient India’s contributions to the

world of science are many. Throughout

the ages, there came people from

different racial, geographical and

religious backgrounds all of whom made

a direct impact on the socio-economic

life and indirectly on the scientific aptitude

and attitude.

Indian science and technology dates

back to prehistoric human activity at

Mehrgarh in present day Pakistan and

continues through the Indus valley

civilization. The Indus Valley civilization is a

term used to refer to the cultures of the

Indus and Ghaggar-Hakra rivers stretching

from Neolithic Mehrgarh period down to

the Iron Age or Indo-Gangetic tradition.

The mature phase of this civilization was

the Harappan civilization (3300-1300 BC),

followed by the Vedic civilization (2000-

600BC).

Mehrgarh Culture

(7000-3300 BC)Mehrgarh is one of the most important

Neolithic sites of the world and lies on the

‘kachi plain’ of today’s Balochistan located

near the Bolan pass, to the west of Indus

valley and between the present day

Pakistani cities of Quetta, Kalat and Sibi.

Mehrgarh shows evidences of tools

with local copper ore, containers made

with bitumen, domestication of plants and

animals and tanning. Bitumen is a mixture

of organic liquids that are highly viscous,

black, sticky, soluble in carbon disulfide and

composed of highly condensed polycyclic

aromatic hydrocarbons.

In Apri l 2006, the journal Nature

announced that the oldest evidence in

human history for the drilling of tooth in vivo,

that is, in a living person, was found in

Mehrgarh around 7000 BC. It involved

curing tooth-related disorders with drills

operated by skilled bead craftsmen. These

interesting findings provide evidence of a

long tradition of a type of proto-dentistry

in an early farming culture.

At Neolithic Mehrgarh, flint drill heads

were found in stone assemblages

associated with beads of bone, steatite,

shell, calcite, turquoise, lapis lazuli and

carnelian. Using models of these drill tips,

methods for dri l l ing based on the

ethnographic literature were constructed

and it was found that a bow drill tipped

with a flinthead required less than a minute

to produce similar holes in human enamel.

Presumably, the know-how originally

developed by skilled artisans for bead

production was successfully transferred to

Here’s a look at some of the significantcontributions to science India has made

through the ages.

Mehrgarh pottery

This image shows a drilled molar crown fromMehrgarh. A hole about a tenth of an inch(2.6 millimeters) wide was drilled in the center of thecrown. The hole shows smoothing, indicating it wasdrilled well before the death of the individual.(Courtesy: Nature)

9 SCIENCE REPORTER, AUGUST 2011

drilling of teeth in a form of proto-dentistry.

A modern reconstruction of this form of

dentistry has shown that the methods used

were reliable and effective.

Harappan Civilization

(3300-1300 BC)The size and prosperity of the

Indus civi l ization grew as a result of

innovations in irrigation and drainage

systems, which eventually led to more

planned settlements. This irrigation system

also included artificial reservoirs at Girnar

dating back to 3000 BC and an early

canal irr igation system from 2600 BC

onwards.

By 2800 BC private bathrooms,

located on the ground floor, were found

in many houses of the Indus civilization.

Pottery pipes in walls allowed drainage of

water and there was, in some cases,

provision of a crib for sitting in toilets.

‘Western-style’ toilets were made from

bricks and wooden toilet seats were used

on top. The waste was transmitted via the

extensive drainage systems in their

settlements.

Large-scale sanitary sewer systems

were in place by 2700 BC. The drains were

7-10 feet wide and 2 feet below ground

level. The sewage was then led into

cesspools, built at the intersection of two

drains, which had stairs leading to them

for periodic cleaning. Plumbing using

earthenware plumbing pipes with broad

flanges for easy joining with asphalt to stop

leaks was in place.

The world’s first dock at Lothal in 2400

BC was built away from the main current

to avoid silt deposition. Contemporary

oceanographers believe that Harappans

must have had knowledge relating to

tides, hydrography and marit ime

engineering in order to build such a dock

equipped to berth and service ships.

Using weights and measures, the

inhabitants developed a system of

standardization. This technical

standardization enabled gauging devices

to be effectively used in angular

measurement and measurement for

construction. In case of some devices,

calibration was also found with multiple

subdivisions.

Evidence of an early furnace, animal

drawn plough and ovens has been

discovered from excavations at Balakot

(in present day Pakistan). Furnaces might

have been used for the manufacture of

ceramic objects. Malhar, Dadupur, Raja

Nala ka Ti la and Lahuradewa

archeological sites present in Uttar Pradesh

(U.P.) show implements from the period

between 1800 BC-1200 BC.

In the development of swords as

weapons of war, those found at Mohenjo-

daro have a tang and rivet to hold the

handle exactly as found in Palestine, where

such implements were associated with the

Hyksos (1800-1500 BC). Copper harpoons

found in the Indus Valley were similar to

those found in Europe and elsewhere in

Asia.

IndianScienceThrough The

AgesThe Mehrgarh civilization

JAIMINI SARKAR

A complete set of stone tools found in a Mehrgarh grave. Such tool sets were presumably buried with their owner.

Indian war rockets wereformidable weapons beforesuch rockets were used inEurope. They had bamboorods, a rocket-body lashed tothe rod, and iron points.

Cover Story

Polished Stone Axe Flint Cores

Microliths

Unretouched Flint Blades

10SCIENCE REPORTER, AUGUST 2011

Swords have been recovered in

archeological findings throughout the

Ganges-Jamuna Doab regions of India

consisting of bronze but more commonly

copper. Copper axes were also

discovered at Harappan sites (Harappa,

Shahi-tump and Chanhu-daro) but were

similar to those found at North Persian sites

(Hissar III, Shah Tepe, Turang Tepe) and

Akkadian sites (Assur, Sialk B cemetery).

Early Iron objects found in India can

be dated to 1400 BC by employing the

method of carbon dating. By the early 13th

century BC, iron smelting was practiced

on a bigger scale in India. In case of

southern India especially present day

Mysore, iron was employed on a large

scale as early as 11th to 12th centuries BC.

Vedic Civilization

(2000-600 BC)The Vedic civilization was based in the

northern and northwestern parts of the

Indian subcontinent. Scholars place the

Vedic period in the second and first

millennia BC continuing up to the 6 th

century BC.

The religious texts of Vedic period

provide evidence of the use of large

numbers as high as 1012 (1200-900 BC).

Vedanga Jyotisa details several important

aspects of time and seasons, including

lunar months, solar months and their

adjustment by lunar leap month of

Adhimasa. Twenty-seven constellations,

eclipses, seven planets and 12 signs of the

zodiac were also known at that time.

In the 8 th centur y BC, an Indian

mathematician, Baudhayana composed

the Sulba Sutra giving rules for the

construction of altars which contained

several important mathematical results. The

famous Pythagorean theorem is believed

to have been invented by Baudhayana

first. He solved the problem of finding a

circle whose area is the same as that of a

square as well gave the formula for the

square root of two.

Literature of the Vedic period in India

offers early records of veterinar y and

human medicine. Leprosy is mentioned in

the Sushruta Samhita (6th century BC), which

also mentions cataract surgery performed

with a special tool called the Jabamukhi

Salaka where a curved needle was used

to loosen the lens and push the cataract

out of the field of vision. The eye would

later be soaked with warm butter and then

bandaged. Though this method was

successful, Sushruta mentioned that it

should only be used when necessary.

During the 5th century BC, the scholar

Panini made several discoveries in the field

of phonetics, phonology and morphology.

Metal currency was minted in India before

5th century BC with coins being made of

silver and copper, bearing animal and

plant symbols on them.

Post Mahajanapadas

(400 BC-400 AD)This era was an interesting era of Indian

histor y. Alexander invaded the

northwestern part of the Indian

subcontinent and the first United Kingdom

was established under the rule of

Chandragupta Maur ya, a student of

Chanakya. The Maur ya Empire

maintained diplomatic relations with the

Greek world as Chandragupta married the

daughter of Alexander ’s general,

Seleucus. This era thus shows prominent

impact of European science and culture

on the Indian subcontinent.

The Arthashastra written by Chanakya

in the 4 th centur y BC mentions the

construction of dams and bridges. The use

of suspension bridges using plaited

bamboo and iron chains was also seen in

this period. Apart from trade and

commerce, the book also discusses

about agriculture, working of mines and

factories, horticulture, irrigation, waterways,

ships, navigation, f isheries and

slaughterhouses.

The contacts between India and the

western world, which Chandragupta

Maurya had established, continued during

the reign of his son Bindusara and

grandson Ashoka.

A typical small housewith 2 to 4 rooms atMehrgarh would havelooked like this and waslikely to have housed afamily.

Cover Story

Reed Thatch

Wooden Poles

Twigs

Window

Mud-brick wall

11 SCIENCE REPORTER, AUGUST 2011

Ashoka was a great builder. His famous

many-pillared hall at Patliputra was dug

out by archeologists and is st i l l in a

marvelous state of preservation. The

wooden logs that were used to build it are

as smooth and perfect as the day they

were laid, more than two thousand years

ago. This would be surprising anywhere,

but in India it is more so, for the climate

wears them away and insects eat them

up. There must have been some kind of

special treatment for the wood used in

such constructions.

Institutions created specifically to

care for the ill appeared in early India.

King Ashoka is said to have founded at

least 18 hospitals around 230 BC, with

physicians and nursing staff, the expense

being borne from the royal treasur y.

Ashoka erected two kinds of hospitals—

for people and for animals. Where there

were no healing herbs for people and

animals, he ordered they should be bought

and planted.

Though the evidence of the first rock-

cut step wells in India dates back to 200-

400 AD, the step wells constructed at

Dhank (550-625 AD) and stepped ponds

at Bhinmal (also known as Shrimal, 72 km

south of Jalore town in Rajasthan) are still

preserved in proper shape. Step wells are

wells in which water can be reached by

descending a set of steps. It can be

multistoried also, in which a bullock turns

the water wheel to raise the water in the

well to the first or second floor.

The city of Mohenjo-daro also had

wells and they may have been the

predecessors of these step wells, as

around 700 wells were discovered in just

one section of the city. Leading scholars

believe that the people of the Indus valley

civilization invented cylindrical brick-lined

wells.

By the beginning of the Common Era

(AD), glass was being used for ornaments

and casing. New techniques were added

in this field because of the contact with

the Greco-Roman world. The Satavahana

period further reveals short cylinders of

composite glass, including those

displaying a lemon-yellow matrix covered

with green glass.

Before the beginning of the Common

Era, Wootz steel originated in India. Wootz

steel was widely exported and traded

throughout ancient Europe and the Arab

world, and became particularly famous in

the Middle East, where it was known as

Damascus steel. Archaeological evidence

suggests that this manufacturing process

was already in existence in South India

even before the Christian era.

The bow instruments used in the

second century in textile are also a gift to

the world from India. These carding

devices are called Kaman and Dhunaki

and would loosen the texture of the fiber

by means of the vibrating string.

Early use of diamonds as gemstones

originated in India. Golconda served as

an important center for diamonds in

central India. Diamonds were exported to

“The Great Bath” at Mohenjo-daro (above);Sewer drains at Mohenjo-daro (right);The city of Harappa had a sophisticateddrainage system perhaps as early as 6,000years before the present (extreme right)

Standardized weights and measures used in the Induscivilization

Cover Story

12SCIENCE REPORTER, AUGUST 2011

other parts of the world also. Literature

written at the beginning of the third century

describes strength, regularity, brilliance,

abil ity to scratch metals and good

refractive properties as the desirable

qualities of diamond.

The Iron pillar of Delhi constructed at

the time of Chandragupta II Vikramaditya

(375-413 AD) is still a marvel because of

the metals used in its construction. The pillar

is 98% pure wrought iron and is a testament

to the high level of skills achieved by

ancient Indian metallurgists in the

extraction and processing of iron. It has

attracted the attention of archeologists

and metallurgists as it has withstood

corrosion for over 1600 yrs in the open air.

The pillar ’s resistance to corrosion is

explained by a passive protective film at

the iron-rust interface. The presence of

second phase particles (slag and

unreduced iron oxides) in the

microstructure of the iron, that of high

amounts of phosphorus in the metal and

the alternate wetting and drying existing

under atmospheric conditions are the

three main factors in the three stage

formation of that protective passive film.

India is one of the probable places

of origin of the spinning wheel. The device

may have reached Europe from India in

the 14th century AD. The Charkhi in some

parts of the region was also driven by

waterpower. The Ajanta caves yield

evidence of a single roller cotton gin in

use by the 5th century AD.

This period was the golden age of

Indian mathematics and astronomy where

many Indian scholars contributed

The well in the citadel of Harappa (the round opening near the centre of the photograph) was almost certainlythe permanent source of fresh water on top of a defensible hill that made the site of Harappa such an importantcentre of the Indus culture.

The ruins at Patliputra

Tipu Sultan’s rockets

The rustless wonder—Iron Pillar in Delhi(above & right)

Cover Story

13 SCIENCE REPORTER, AUGUST 2011

seminally. Pingala (300-200 AD) was famous

for his work, Chandas Shastra, a Sanskrit

treatise on prosody considered as one of

the Vedanga. He developed advanced

mathematical concepts for describing the

patterns of prosody. Pingala presents

the first known description of a binary

numeral system. He described the binary

numeral system in connection with the

listing of Vedic meters with short and long

syllables. His discussion of the

combinatorics of meter corresponds to the

binomial theorem. Pingala’s work also

contains the basic ideas of Fibonacci

number and a presentation of the Pascal’s

triangle.

The use of negative numbers was

known in early India, and their role in

situations like mathematical problems of

debt was understood and consistent rules

for working with these numbers were

formulated.

Medieval Period (500 AD-1600

AD)Aryabhata (476–550 AD) was the great

mathematician-astronomer from the

classical age of Indian mathematics and

astronomy. His most famous works are the

Aryabhatiya (499 AD, when he was 23 years

old) and the Arya-siddhanta.

Brahmagupta (598–668 AD), another

great mathematician and astronomer

wrote important treatise on mathematics

and astronomy in

Brahamasphutasiddhanta in 628 AD. He

gave solutions for the general l inear

equation, two equivalent solutions to the

general quadratic equation, explained

how to find cube and cube root of an

integer, rules for facil i tating the

computation of squares and square roots

and gave rules for dealing with five types

of combinations of fractions.

He was able to find (integral) solutions

of Pell’s equation. Brahmagupta’s most

famous result in geometry is his formula for

cyclic quadrilaterals, a theorem on rational

triangles and values of ð (pi).

In chapter seven of his

Brahmasphutasiddhanta, entitled Lunar

Crescent, Brahmagupta rebuts the idea

that the Moon is farther from the Earth than

the Sun, an idea maintained in scriptures.

He does this by explaining the illumination

of the Moon by the Sun.

During the 1st millennium AD, the

Vaisheshika School of atomism proposed

that atoms are indivisible and eternal, can

neither be created nor destroyed and

each one possessed its own distinct

individuality. This concept was further

elaborated by philosophers of the Buddhist

school of atomism, Dharamkirt i and

Dignaga, in the 7th centur y AD. They

considered atoms to be point sized,

duration less and made of energy.

Bhâskara-I, the 7 th centur y

mathematician, was apparently the first to

write numbers in the Hindu-Arabic decimal

system with a circle for the zero, and who

gave a unique and remarkable rational

approximation of the sine function in his

commentary on Aryabhata’s work.

The decimal number system also

originated in India. Other cultures

discovered a few features of this number

system but the system, in its entirety, was

compiled in India, where it attained

coherence and completion. By the 9 th

century AD, this complete number system

was in existence in India.

The concept of 0 as a number, and

not merely a symbol for separation is

attr ibuted to India where practical

calculations were carried out using zero,

which was treated like any other number

by the 9 th century AD, even in case of

division.

Bhaskara-II or Bhaskara Acharya was

head of an astronomical observatory at

Ujjain, the leading mathematical center

of ancient India. Bhaskara-II mainly

contributed to the field of mathematics,

arithmetic, algebra, tr igonometr y,

calculus, astronomy and engineering.

Conceptual design for a perpetual motion

machine by Bhaskara II dates to 1150 AD.

He described a wheel that he claimed

would run forever. He used a measuring

device known as Yasti-yantra. This device

could vary from a simple stick to V-shaped

staffs designed specifically for determining

angles with the help of a calibrated scale.

Rasaratna Samuccaya written during

the 8 th centur y AD gives elaborate

description of various complex

metallurgical processes. It explains the

existence of two types of ores for Zinc

metal, one of which is ideal for metal

extraction while the other is used for

medicinal purpose.

India also became a major center

for production and processing of

Indigofera tinctoria, a variety of indigo that

was used and domesticated in India for

use as a dye.

Evidence of microbial inoculation

and variolation for smallpox is found in the

8 th centur y, when Madhav wrote the

The use of mines andcounter-mines with explosivecharges of gunpowder ismentioned for the times ofAkbar and Jahângir.Evidence of an early furnace,animal drawn plough andovens has been discoveredfrom excavations at Balakot(in present day Pakistan).

Cover Story

14SCIENCE REPORTER, AUGUST 2011

Nidâna, a 79-chapter book that l ists

diseases along with their causes,

symptoms, and complications. He

included a special chapter on smallpox

(Masûrikâ) and described the method of

inoculation to protect against smallpox.

Treatment was done by inoculation with

year-old smallpox matter. The inoculators

would travel all across India pricking the

skin of the arm with a small metal instrument

using “variolous matter” taken from pustules

produced by the previous year ’s

inoculations. The British doctor J.Z. Holwell

based on observations made during his

residence in Bengal in an account to the

College of Physicians in London in 1767

confirmed the effectiveness of this system.

The Scholars of Kerala School of

astronomy and mathematics, especially

Madhava of Sangamagrama, made

important contributions to the field of

geometry by stating the infinite series for ð

(1340-1425 AD). Madhava made use of

the series expansion of arctanx to obtain

an infinite series expression, now known as

the Madhava-Gregory series, for ð. They

used an improved series to derive a

rational expression 104348 / 33215 for ð,

correct up to nine decimal places, i.e.

3.141592653.

Ali Kashmiri ibn Luqman (1589-90 AD)

invented the Seamless celestial globe,

which was later produced in the Mughal

Empire. Before they were rediscovered in

the 1980s, it was believed by modern

metallurgists to be technically impossible

to produce metal globes without any

seams, even with modern technology.

These Mughal metallurgists pioneered the

method of lost-wax casting in order to

produce these globes.

Indian war rockets were formidable

weapons before such rockets were used

in Europe. They had bamboo rods, a

rocket-body lashed to the rod, and iron

points. They were directed at the target

and fired by lighting the fuse, but the

trajectory was rather erratic. The use of

mines and counter-mines with explosive

charges of gunpowder is mentioned for

the times of Akbar and Jahângir.

Later, Hyder Ali, prince of Mysore,

developed war rockets with an innovation.

He used metal cylinders to contain the

combustion powder. Although the

hammered soft iron he used was crude,

the bursting strength of the container of

black powder was much higher than the

earlier paper construction. Thus a greater

internal pressure was possible, with a

resultant greater thrust of the propulsive

jet.

Hyder Ali’s son, Tipu Sultan, continued

to develop and expand the use of rocket

weapons, reportedly increasing

the number of rocket troops from 1,200 to

5,000. In battles at Seringapatam in

1792 and 1799, these rockets were

used with considerable effect against the

British.

Fathullah Shirazi, a Persian-Indian

polymath and mechanical engineer who

worked for Akbar in the Mughal Empire,

invented the auto-cannon, the earliest

multi-shot gun in 1582.

The scholar Sadiq Isfahani of Jaunpur

compiled an atlas of parts of the world.

The 32-sheet atlas is part of a larger

scholarly work compiled by Isfahani during

1647 AD.

Dr. Jaimini Sarkar is a freelance science writer.Address: C/o M.L. Dhane, 702, M2/C, PratikshaNagar C.H.S, Pratiksha Nagar, Sion (E), Mumbai-400022; Email: jaimini_dhane@hotmail.com

The “Granary” at Harappa

The Indus Valley civilizationis a term used to refer to thecultures of the Indus andGhaggar-Hakra riversstretching from NeolithicMehrgarh period down tothe Iron Age or Indo-Gangetic tradition.

Cover Story