History of science and technology in the Indian subcontinent
|Outline of South Asian history|
The history of science and technology in the Indian Subcontinent begins with prehistoric human activity the Indus Valley Civilization to early states and empires. Following independence science and technology in the Republic of India has included automobile engineering, information technology, communications as well as space, polar, and nuclear sciences.
By 5500 BCE a number of sites similar to Mehrgarh had appeared, forming the basis of later chalcolithic cultures. The inhabitants of these sites maintained trading relations with Near East and Central Asia.
This was developed in the Indus Valley Civilization by around 4500 BCE. The size and prosperity of the Indus civilization grew as a result of this innovation, which eventually led to more planned settlements making use of drainage and sewerage. Sophisticated irrigation and water storage systems were developed by the Indus Valley Civilization, including artificial reservoirs at Girnar dated to 3000 BCE, and an early canal irrigation system from c. 2600 BCE. Cotton was cultivated in the region by the 5th–4th millennia BCE. Sugarcane was originally from tropical South and Southeast Asia. Different species likely originated in different locations with S. barberi originating in India, and S. edule and S. officinarum coming from New Guinea.
The inhabitants of the Indus valley developed a system of standardization, using weights and measures, evident by the excavations made at the Indus valley sites. This technical standardization enabled gauging devices to be effectively used in angular measurement and measurement for construction. Calibration was also found in measuring devices along with multiple subdivisions in case of some devices. One of the earliest known docks is at Lothal (2400 BCE), located away from the main current to avoid deposition of silt. Modern oceanographers have observed that the Harappans must have possessed knowledge relating to tides in order to build such a dock on the ever-shifting course of the Sabarmati, as well as exemplary hydrography and maritime engineering.
Excavations at Balakot (c. 2500–1900 BCE), present day Pakistan, have yielded evidence of an early furnace. The furnace was most likely used for the manufacturing of ceramic objects. Ovens, dating back to the civilization's mature phase (c. 2500–1900 BCE), were also excavated at Balakot. The Kalibangan archeological site further yields evidence of potshaped hearths, which at one site have been found both on ground and underground. Kilns with fire and kiln chambers have also been found at the Kalibangan site.
Based on archaeological and textual evidence, Joseph E. Schwartzberg (2008)—a University of Minnesota professor emeritus of geography—traces the origins of Indian cartography to the Indus Valley Civilization (c. 2500–1900 BCE). The use of large scale constructional plans, cosmological drawings, and cartographic material was known in India with some regularity since the Vedic period (2nd - 1st millennium BCE). Climatic conditions were responsible for the destruction of most of the evidence, however, a number of excavated surveying instruments and measuring rods have yielded convincing evidence of early cartographic activity. Schwartzberg (2008)—on the subject of surviving maps—further holds that: 'Though not numerous, a number of map-like graffiti appear among the thousands of Stone Age Indian cave paintings; and at least one complex Mesolithic diagram is believed to be a representation of the cosmos.'
Archeological evidence of an animal-drawn plough dates back to 2500 BCE in the Indus Valley Civilization. The earliest available swords of copper discovered from the Harappan sites date back to 2300 BCE. Swords have been recovered in archaeological findings throughout the Ganges–Jamuna Doab region of India, consisting of bronze but more commonly copper.
The religious texts of the Vedic Period provide evidence for the use of large numbers. By the time of the last Veda, the Yajurvedasaṃhitā (1200-900 BCE), numbers as high as were being included in the texts. For example, the mantra (sacrificial formula) at the end of the annahoma ("food-oblation rite") performed during the aśvamedha ("an allegory for a horse sacrifice"), and uttered just before-, during-, and just after sunrise, invokes powers of ten from a hundred to a trillion. The Satapatha Brahmana (9th century BCE) contains rules for ritual geometric constructions that are similar to the Sulba Sutras.
Baudhayana (c. 8th century BCE) composed the Baudhayana Sulba Sutra, which contains examples of simple Pythagorean triples, such as: , , , , and  as well as a statement of the Pythagorean theorem for the sides of a square: "The rope which is stretched across the diagonal of a square produces an area double the size of the original square." It also contains the general statement of the Pythagorean theorem (for the sides of a rectangle): "The rope stretched along the length of the diagonal of a rectangle makes an area which the vertical and horizontal sides make together." Baudhayana gives a formula for the square root of two. Mesopotamian influence at this stage is considered likely.
The earliest Indian astronomical text—named Vedānga Jyotiṣa— attributed to Lagadha, is considered one of the oldest astronomical texts, dating from 1400–1200 BCE (with the extant form possibly from 700–600 BCE), it details several astronomical attributes generally applied for timing social and religious events. It also details astronomical calculations, calendrical studies, and establishes rules for empirical observation. Since the Vedānga Jyotiṣa is a religious text, it has connections with Indian astrology and details several important aspects of the time and seasons, including lunar months, solar months, and their adjustment by a lunar leap month of Adhimāsa. Ritus and Yugas are also described. Tripathi (2008) holds that "Twenty-seven constellations, eclipses, seven planets, and twelve signs of the zodiac were also known at that time."
The Egyptian Papyrus of Kahun (1900 BCE) and literature of the Vedic period in India offer early records of veterinary medicine. Kearns & Nash (2008) state that mention of leprosy is described in the medical treatise Sushruta Samhita (6th century BCE). The Sushruta Samhita an Ayurvedic text contains 184 chapters and description of 1120 illnesses, 700 medicinal plants, a detailed study on Anatomy, 64 preparations from mineral sources and 57 preparations based on animal sources. However, The Oxford Illustrated Companion to Medicine holds that the mention of leprosy, as well as ritualistic cures for it, were described in the Hindu religious book Atharva-veda, written in 1500–1200 BCE.
Cataract surgery was known to the physician Sushruta (6th century BCE). Traditional cataract surgery was performed with a special tool called the Jabamukhi Salaka, a curved needle 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, Susruta cautioned that it should only be used when necessary. The removal of cataract by surgery was also introduced into China from India.
During the 5th century BCE, the scholar Pāṇini had made several discoveries in the fields of phonetics, phonology, and morphology. Pāṇini's morphological analysis remained more advanced than any equivalent Western theory until the mid-20th century. Metal currency was minted in India before the 5th century BCE, with coinage (400 BCE—100 CE) being made of silver and copper, bearing animal and plant symbols on them.
Zinc mines of Zawar, near Udaipur, Rajasthan, were active during 400 BCE. Diverse specimens of swords have been discovered in Fatehgarh, where there are several varieties of hilt. These swords have been variously dated to periods between 1700–1400 BCE, but were probably used more extensively during the opening centuries of the 1st millennium BCE. Archaeological sites in such as Malhar, Dadupur, Raja Nala Ka Tila and Lahuradewa in present-day Uttar Pradesh show iron implements from the period between 1800 BCE and 1200 BCE. Early iron objects found in India can be dated to 1400 BCE by employing the method of radio carbon dating. Some scholars believe that by the early 13th century BCE iron smelting was practiced on a bigger scale in India, suggesting that the date of the technology's inception may be placed earlier. In Southern India (present day Mysore) iron appeared as early as 11th to 12th centuries BCE. These developments were too early for any significant close contact with the northwest of the country.
Post Maha Janapadas—High Middle Ages
The Arthashastra of Kautilya mentions the construction of dams and bridges. The use of suspension bridges using plaited bamboo and iron chain was visible by about the 4th century. The stupa, the precursor of the pagoda and torii, was constructed by the 3rd century BCE. Rock-cut step wells in the region date from 200-400 CE. Subsequently, the construction of wells at Dhank (550-625 CE) and stepped ponds at Bhinmal (850-950 CE) took place.
During the 1st millennium BCE, the Vaisheshika school of atomism was founded. The most important proponent of this school was Kanada, an Indian philosopher who lived around 200 BCE. The school proposed that atoms are indivisible and eternal, can neither be created nor destroyed, and that each one possesses its own distinct viśeṣa (individuality). It was further elaborated on by the Buddhist school of atomism, of which the philosophers Dharmakirti and Dignāga in the 7th century CE were the most important proponents. They considered atoms to be point-sized, durationless, and made of energy.
By the beginning of the Common Era glass was being used for ornaments and casing in the region. Contact with the Greco-Roman world added newer techniques, and local artisans learnt methods of glass molding, decorating and coloring by the early centuries of the Common Era. The Satavahana period further reveals short cylinders of composite glass, including those displaying a lemon yellow matrix covered with green glass. Wootz originated in the region before the beginning of the common era. Wootz was exported and traded throughout Europe, China, the Arab world, and became particularly famous in the Middle East, where it became known as Damascus steel. Archaeological evidence suggests that manufacturing process for Wootz was also in existence in South India before the Christian era.
Evidence for using bow-instruments for carding comes from India (2nd century CE). The mining of diamonds and its early use as gemstones originated in India. Golconda served as an important early center for diamond mining and processing. Diamonds were then exported to other parts of the world. Early reference to diamonds comes from Sanskrit texts. The Arthashastra also mentions diamond trade in the region. The Iron pillar of Delhi was erected at the times of Chandragupta II Vikramaditya (375–413). The Rasaratna Samuccaya (800) 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.
The origins of the spinning wheel are unclear but India is one of the probable places of its origin. The device certainly reached Europe from India by the 14th century. The cotton gin was invented in India as a mechanical device known as charkhi, the "wooden-worm-worked roller". This mechanical device was, in some parts of the region, driven by water power. The Ajanta caves yield evidence of a single roller cotton gin in use by the 5th century. This cotton gin was used until further innovations were made in form of foot powered gins. Chinese documents confirm at least two missions to India, initiated in 647, for obtaining technology for sugar-refining. Each mission returned with different results on refining sugar. (300-200 BCE) was a musical theorist who authored a Sanskrit treatise on prosody. There is evidence that in his work on the enumeration of syllabic combinations, Pingala stumbled upon both the Pascal triangle and Binomial coefficients, although he did not have knowledge of the Binomial theorem itself. A description of binary numbers is also found in the works of Pingala. The Indians also developed the use of the law of signs in multiplication. Negative numbers and the subtrahend had been used in East Asia since the 2nd century BCE, and Indian mathematicians were aware of negative numbers by the 7th century CE, and their role in mathematical problems of debt was understood. Although the Indians were not the first to use the subtrahend, they were the first to establish the "law of signs" with regards to the multiplication of positive and negative numbers, which did not appear in East Asian texts until 1299. Mostly consistent and correct rules for working with negative numbers were formulated, and the diffusion of these rules led the Arab intermediaries to pass it on to Europe.
A decimal number system using hieroglyphics dates back to 3000 BC in Egypt, and was later in use in ancient India where the modern numeration system was developed. By the 9th century CE, the Hindu–Arabic numeral system was transmitted from India through the Middle East and to the rest of the world. The concept of 0 as a number, and not merely a symbol for separation is attributed to India. In India, practical calculations were carried out using zero, which was treated like any other number by the 9th century CE, even in case of division. Brahmagupta (598–668) was able to find (integral) solutions of Pell's equation. Conceptual design for a perpetual motion machine by Bhaskara II dates to 1150. He described a wheel that he claimed would run forever.
The trigonometric functions of sine and versine, from which it was trivial to derive the cosine, were used by the mathematician, Aryabhata, in the late 5th century. The calculus theorem now known as "Rolle's theorem" was stated by mathematician, Bhāskara II, in the 12th century.
Indigo was used as a dye in India, which was also a major center for its production and processing. The Indigofera tinctoria variety of Indigo was domesticated in India. Indigo, used as a dye, made its way to the Greeks and the Romans via various trade routes, and was valued as a luxury product. The cashmere wool fiber, also known as pashm or pashmina, was used in the handmade shawls of Kashmir. The woolen shawls from Kashmir region find written mention between 3rd century BCE and the 11th century CE. Crystallized sugar was discovered by the time of the Gupta dynasty, and the earliest reference to candied sugar comes from India. Jute was also cultivated in India. Muslin was named after the city where Europeans first encountered it, Mosul, in what is now Iraq, but the fabric actually originated from Dhaka in what is now Bangladesh. In the 9th century, an Arab merchant named Sulaiman makes note of the material's origin in Bengal (known as Ruhml in Arabic).
European scholar Francesco I reproduced a number of Indian maps in his magnum opus La Cartografia Antica dell India. Out of these maps, two have been reproduced using a manuscript of Lokaprakasa, originally compiled by the polymath Ksemendra (Kashmir, 11th century CE), as a source. The other manuscript, used as a source by Francesco I, is titled Samgraha'.
Late Middle Ages
Madhava of Sangamagrama (c. 1340 – 1425) and his Kerala school of astronomy and mathematics developed and founded mathematical analysis. The infinite series for π was stated by him and he made use of the series expansion of to obtain an infinite series expression, now known as the Madhava-Gregory series, for . Their rational approximation of the error for the finite sum of their series are of particular interest. They manipulated the error term to derive a faster converging series for . They used the improved series to derive a rational expression, for correct up to nine decimal places, i.e. . The development of the series expansions for trigonometric functions (sine, cosine, and arc tangent) was carried out by mathematicians of the Kerala School in the 15th century CE. Their work, completed two centuries before the invention of calculus in Europe, provided what is now considered the first example of a power series (apart from geometric series).
Shēr Shāh of northern India issued silver currency bearing Islamic motifs, later imitated by the Mughal empire. The Chinese merchant Ma Huan (1413–51) noted that gold coins, known as fanam, were issued in Cochin and weighed a total of one fen and one li according to the Chinese standards. They were of fine quality and could be exchanged in China for 15 silver coins of four-li weight each.
In 1500, Nilakantha Somayaji of the Kerala school of astronomy and mathematics, in his Tantrasangraha, revised Aryabhata's elliptical model for the planets Mercury and Venus. His equation of the centre for these planets remained the most accurate until the time of Johannes Kepler in the 17th century.
The seamless celestial globe was invented in Kashmir by Ali Kashmiri ibn Luqman in 998 AH (1589-90 CE), and twenty other such globes were later produced in Lahore and Kashmir during 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.
Gunpowder and gunpowder weapons were transmitted to India through the Mongol invasions of India. The Mongols were defeated by Alauddin Khilji of the Delhi Sultanate, and some of the Mongol soldiers remained in northern India after their conversion to Islam. It was written in the Tarikh-i Firishta (1606–1607) that the envoy of the Mongol ruler Hulagu Khan was presented with a pyrotechnics display upon his arrival in Delhi in 1258 CE. As a part of an embassy to India by Timurid leader Shah Rukh (1405–1447), 'Abd al-Razzaq mentioned naphtha-throwers mounted on elephants and a variety of pyrotechnics put on display. Firearms known as top-o-tufak also existed in the Vijayanagara Empire by as early as 1366 CE. From then on the employment of gunpowder warfare in the region was prevalent, with events such as the siege of Belgaum in 1473 CE by the Sultan Muhammad Shah Bahmani.
In A History of Greek Fire and Gunpowder, James Riddick Partington describes the gunpowder warfare of 16th and 17th century Mughal India, and writes that "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 Jahāngir."
By the 16th century, Indians were manufacturing a diverse variety of firearms; large guns in particular, became visible in Tanjore, Dacca, Bijapur and Murshidabad. Guns made of bronze were recovered from Calicut (1504) and Diu (1533). Gujarāt supplied Europe saltpeter for use in gunpowder warfare during the 17th century. Bengal and Mālwa participated in saltpeter production. The Dutch, French, Portuguese, and English used Chhapra as a center of saltpeter refining.
The construction of water works and aspects of water technology in India is described in Arabic and Persian works. During medieval times, the diffusion of Indian and Persian irrigation technologies gave rise to an advanced irrigation system which bought about economic growth and also helped in the growth of material culture. The founder of the cashmere wool industry is traditionally held to be the 15th-century ruler of Kashmir, Zayn-ul-Abidin, who introduced weavers from Central Asia.
The scholar Sadiq Isfahani of Jaunpur compiled an atlas of the parts of the world which he held to be 'suitable for human life'. The 32 sheet atlas—with maps oriented towards the south as was the case with Islamic works of the era—is part of a larger scholarly work compiled by Isfahani during 1647 CE. According to Joseph E. Schwartzberg (2008): 'The largest known Indian map, depicting the former Rajput capital at Amber in remarkable house-by-house detail, measures 661 × 645 cm. (260 × 254 in., or approximately 22 × 21 ft).'
Early volumes of the Encyclopædia Britannica described cartographic charts made by the seafaring Dravidian people. In Encyclopædia Britannica (2008), Stephen Oliver Fought & John F. Guilmartin, Jr. describe the gunpowder technology in 18th-century Mysore:
Hyder Ali, prince of Mysore, developed war rockets with an important change: the use of 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. The rocket body was lashed with leather thongs to a long bamboo stick. Range was perhaps up to three-quarters of a mile (more than a kilometre). Although individually these rockets were not accurate, dispersion error became less important when large numbers were fired rapidly in mass attacks. They were particularly effective against cavalry and were hurled into the air, after lighting, or skimmed along the hard dry ground. Hyder Ali's son, Tippu Sultan, continued to develop and expand the use of rocket weapons, reportedly increasing the number of rocket troops from 1,200 to a corps of 5,000. In battles at Seringapatam in 1792 and 1799 these rockets were used with considerable effect against the British.
By the end of the 18th century the postal system in the region had reached high levels of efficiency. According to Thomas Broughton, the Maharaja of Jodhpur sent daily offerings of fresh flowers from his capital to Nathadvara (320 km) and they arrived in time for the first religious Darshan at sunrise. Later this system underwent modernization with the establishment of the British Raj. The Post Office Act XVII of 1837 enabled the Governor-General of India to convey messages by post within the territories of the East India Company. Mail was available to some officials without charge, which became a controversial privilege as the years passed. The Indian Post Office service was established on October 1, 1837. The British also constructed a vast railway network in the region for both strategic and commercial reasons.
The British education system, aimed at producing able civil and administrative services candidates, exposed a number of Indians to foreign institutions. Sir Jagadis Chandra Bose (1858–1937), Prafulla Chandra Ray (1861-1944), Satyendra Nath Bose (1894–1974), Meghnad Saha (1893–1956), P. C. Mahalanobis (1893–1972), Sir C. V. Raman (1888–1970), Subrahmanyan Chandrasekhar (1910–1995), Homi Bhabha (1909–1966), Srinivasa Ramanujan (1887–1920), Vikram Sarabhai (1919–1971), Har Gobind Khorana (1922–2011), and Harish Chandra (1923–1983) were among the notable scholars of this period.
Extensive interaction between colonial and native sciences was seen during most of the colonial era. Western science came to be associated with the requirements of nation building rather than being viewed entirely as a colonial entity, especially as it continued to fuel necessities from agriculture to commerce. Scientists from India also appeared throughout Europe. By the time of India's independence colonial science had assumed importance within the westernized intelligentsia and establishment.
- Science and technology in India
- List of Indian inventions
- Information technology in India
- Project of History of Indian Science, Philosophy and Culture
- List of Indian engineering colleges before 1947
- Digit (magazine)
- Distribution of Acheulian sites in the Siwalik region
- Kenoyer, 230
- Rodda & Ubertini, 279
- Rodda & Ubertini, 161
- Stein, 47
- Sharpe (1998)
- Baber, 23
- Rao, 27–28
- Dales, 3–22 
- Baber, 20
- Finger, 12
- "We now believe that some form of mapping was practiced in what is now India as early as the Mesolithic period, that surveying dates as far back as the Indus Civilization (ca. 2500–1900 BCE), and that the construction of large-scale plans, cosmographic maps, and other cartographic works has occurred continuously at least since the late Vedic age (first millennium BCE)" — Joseph E. Schwartzberg, 1301.
- Schwartzberg, 1301-1302
- Schwartzberg, 1301
- Lal (2001)
- Allchin, 111-112
- Banerji, 673
- Sircar, 62
- Sircar, 67
- Hayashi, 360-361
- Seidenberg, 301-342
- Joseph, 229
- Cooke, 200
- (Boyer 1991, "China and India" p. 207)
- Subbarayappa, B. V. (14 September 1989). "Indian astronomy: An historical perspective". In Biswas, S. K.; Mallik, D. C. V.; Vishveshwara, C. V. Cosmic Perspectives. Cambridge University Press. pp. 25–40. ISBN 978-0-521-34354-1.
- Subbaarayappa, 25-41
- Tripathi, 264-267
- Thrusfield, 2
- Dwivedi & Dwivedi (2007)
- Kearns & Nash (2008)
- Lock etc., 420
- Finger, 66
- Lade & Svoboda, 85
- Encyclopædia Britannica (2008), Linguistics.
- Staal, Frits (1988). Universals: studies in Indian logic and linguistics. University of Chicago Press. p. 47.
- Dhavalikar, 330-338
- Sellwood (2008)
- Allan & Stern (2008)
- Craddock (1983) Cite error: Invalid
<ref>tag; name "Craddock" defined multiple times with different content (see the help page).
- F.R. Allchin, 111-112
- Allchin, 114
- Tewari (2003)
- Ceccarelli, 218
- Drakonoff, 372
- Dikshitar, pg. 332
- Encyclopædia Britannica (2008), suspension bridge.
- Encyclopædia Britannica (2008), Pagoda.
- Japanese Architecture and Art Net Users System (2001), torii.
- Livingston & Beach, xxiii
- Oliver Leaman, Key Concepts in Eastern Philosophy. Routledge, 1999, page 269.
- Chattopadhyaya 1986, pp. 169–70
- Radhakrishnan 2006, p. 202
- (Stcherbatsky 1962 (1930). Vol. 1. P. 19)
- Ghosh, 219
- "Ornaments, Gems etc." (Ch. 10) in Ghosh 1990.
- Srinivasan & Ranganathan
- Srinivasan (1994)
- Srinivasan & Griffiths
- Baber, 57
- Wenk, 535-539
- MSN Encarta (2007), Diamond. Archived 2009-10-31.
- Lee, 685
- Balasubramaniam, R., 2002
- Britannica Concise Encyclopedia (2007), spinning wheel.
- Encyclopeedia Britnnica (2008). spinning.
- MSN Encarta (2008), Spinning. Archived 2009-10-31.
- Baber, 56
- Kieschnick, 258
- Fowler, 11
- Singh, 623-624
- Sanchez & Canton, 37
- Smith (1958), page 258 Cite error: Invalid
<ref>tag; name "Smith" defined multiple times with different content (see the help page).
- Bourbaki (1998), page 49
- Bourbaki 1998, p. 46 Cite error: Invalid
<ref>tag; name "bourbaki46" defined multiple times with different content (see the help page).
- Georges Ifrah: From One to Zero. A Universal History of Numbers, Penguin Books, 1988, ISBN 0-14-009919-0, pp. 200-213 (Egyptian Numerals)
- Ifrah, 346
- Jeffrey Wigelsworth (1 January 2006). Science And Technology in Medieval European Life. Greenwood Publishing Group. p. 18. ISBN 978-0-313-33754-3.
- Britannica Concise Encyclopedia (2007). algebra
- Stillwell, 72-73
- Lynn Townsend White, Jr.
- O'Connor, J. J. & Robertson, E.F. (1996)
- "Geometry, and its branch trigonometry, was the mathematics Indian astronomers used most frequently. In fact, the Indian astronomers in the third or fourth century, using a pre-Ptolemaic Greek table of chords, produced tables of sines and versines, from which it was trivial to derive cosines. This new system of trigonometry, produced in India, was transmitted to the Arabs in the late eighth century and by them, in an expanded form, to the Latin West and the Byzantine East in the twelfth century" - Pingree (2003).
- Broadbent, 307–308
- Kriger & Connah, 120
- Encyclopædia Britannica (2008), cashmere.
- Encyclopædia Britannica (2008), Kashmir shawl.
- Shaffer, 311
- Kieschnick (2003)
- Encyclopædia Britannica (2008), jute.
- Banglapedia (2008), Muslin, Asiatic Society of Bangladesh.
- Ahmad, 5–26
- Sircar 328
- J J O'Connor and E F Robertson. "Mādhava of Sangamagrāma". School of Mathematics and Statistics University of St Andrews, Scotland. Retrieved 2007-09-08.
- Roy, 291-306
- Stillwell, 173
- Chaudhuri, 223
- Joseph, George G. (2000), The Crest of the Peacock: Non-European Roots of Mathematics, Penguin Books, ISBN 0-691-00659-8.
- Savage-Smith (1985)
- Iqtidar Alam Khan (2004). Gunpowder And Firearms: Warfare In Medieval India. Oxford University Press. ISBN 978-0-19-566526-0.
- Iqtidar Alam Khan (25 April 2008). Historical Dictionary of Medieval India. Scarecrow Press. p. 157. ISBN 978-0-8108-5503-8.
- Khan, 9-10
- Partington, 217
- Khan, 10
- Partington, 226
- Partington, 225
- Encyclopædia Britannica (2008), India.
- Encyclopædia Britannica (2008), Chāpra.
- Siddiqui, 52–77
- Schwartzberg, 1302
- Schwartzberg, 1303
- Sircar 330
- Encyclopædia Britannica (2008), rocket and missile system.
- Peabody, 71
- Lowe, 134
- Seaman, 348
- Raja (2006)
- Arnold, 211
- Arnold, 212
- Allan, J. & Stern, S. M. (2008), coin, Encyclopædia Britannica.
- Allchin, F.R. (1979), South Asian Archaeology 1975: Papers from the Third International Conference of the Association of South Asian Archaeologists in Western Europe, Held in Paris edited by J.E.van Lohuizen-de Leeuw, Brill Academic Publishers, ISBN 90-04-05996-2.
- Ahmad, S. (2005), "Rise and Decline of the Economy of Bengal", Asian Affairs, 27 (3): 5–26.
- Arnold, David (2004), The New Cambridge History of India: Science, Technology and Medicine in Colonial India, Cambridge University Press, ISBN 0-521-56319-4.
- Baber, Zaheer (1996), The Science of Empire: Scientific Knowledge, Civilization, and Colonial Rule in India, State University of New York Press, ISBN 0-7914-2919-9.
- Balasubramaniam, R. (2002), Delhi Iron Pillar: New Insights, Indian Institute of Advanced Studies, ISBN 81-7305-223-9.
- BBC (2006), "Stone age man used dentist drill".
- Bourbaki, Nicolas (1998), Elements of the History of Mathematics, Springer, ISBN 3-540-64767-8.
- Broadbent, T. A. A. (1968), "Reviewed work(s): The History of Ancient Indian Mathematics by C. N. Srinivasiengar", The Mathematical Gazette, 52 (381): 307–308.
- Ceccarelli, Marco (2000), International Symposium on History of Machines and Mechanisms: Proceedings HMM Symposium, Springer, ISBN 0-7923-6372-8.
- Chaudhuri, K. N. (1985), Trade and Civilisation in the Indian Ocean, Cambridge University Press, ISBN 0-521-28542-9.
- Craddock, P.T. etc. (1983), Zinc production in medieval India, World Archaeology, 15 (2), Industrial Archaeology.
- Cooke, Roger (2005), The History of Mathematics: A Brief Course, Wiley-Interscience, ISBN 0-471-44459-6.
- Coppa, A. etc. (2006), "Early neolithic tradition of dentistry", Nature, 440: 755-756.
- Dales, George (1974), "Excavations at Balakot, Pakistan, 1973", Journal of Field Archaeology, 1 (1-2): 3–22 .
- Dhavalikar, M. K. (1975), "The beginning of coinage in India", World Archaeology, 6 (3): 330-338, Taylor & Francis.
- Dikshitar, V. R. R. (1993), The Mauryan Polity, Motilal Banarsidass, ISBN 81-208-1023-6.
- Drakonoff, I. M. (1991), Early Antiquity, University of Chicago Press, ISBN 0-226-14465-8.
- Fowler, David (1996), "Binomial Coefficient Function", The American Mathematical Monthly, 103 (1): 1-17.
- Finger, Stanley (2001), Origins of Neuroscience: A History of Explorations Into Brain Function, Oxford University Press, ISBN 0-19-514694-8.
- Ghosh, Amalananda (1990), An Encyclopaedia of Indian Archaeology, Brill Academic Publishers, ISBN 90-04-09262-5.
- Hayashi, Takao (2005), "Indian Mathematics", The Blackwell Companion to Hinduism edited by Gavin Flood, pp. 360–375, Basil Blackwell, ISBN 978-1-4051-3251-0.
- Hopkins, Donald R. (2002), The Greatest Killer: Smallpox in history, University of Chicago Press, ISBN 0-226-35168-8.
- Ifrah, Georges (2000), A Universal History of Numbers: From Prehistory to Computers, Wiley, ISBN 0-471-39340-1.
- Joseph, G. G. (2000), The Crest of the Peacock: The Non-European Roots of Mathematics, Princeton University Press, ISBN 0-691-00659-8.
- Kearns, Susannah C.J. & Nash, June E. (2008), leprosy, Encyclopædia Britannica.
- Kenoyer, J.M. (2006), "Neolithic Period", Encyclopedia of India (vol. 3) edited by Stanley Wolpert, Thomson Gale, ISBN 0-684-31352-9.
- Khan, Iqtidar Alam (1996), Coming of Gunpowder to the Islamic World and North India: Spotlight on the Role of the Mongols, Journal of Asian History 30: 41–5 .
- Kieschnick, John (2003), The Impact of Buddhism on Chinese Material Culture, Princeton University Press, ISBN 0-691-09676-7.
- Kriger, Colleen E. & Connah, Graham (2006), Cloth in West African History, Rowman Altamira, ISBN 0-7591-0422-0.
- Lade, Arnie & Svoboda, Robert (2000), Chinese Medicine and Ayurveda, Motilal Banarsidass, ISBN 81-208-1472-X.
- Lal, R. (2001), "Thematic evolution of ISTRO: transition in scientific issues and research focus from 1955 to 2000", Soil and Tillage Research, 61 (1-2): 3–12 .
- Lee, Sunggyu (2006), Encyclopedia of Chemical Processing, CRC Press, ISBN 0-8247-5563-4.
- Livingston, Morna & Beach, Milo (2002), Steps to Water: The Ancient Stepwells of India, Princeton Architectural Press, ISBN 1-56898-324-7.
- Lock, Stephen etc. (2001), The Oxford Illustrated Companion to Medicine, Oxford University Press, ISBN 0-19-262950-6.
- Lowe, Robson (1951), The Encyclopedia of British Empire Postage Stamps, 1661–1951 (vol. 3).
- MSNBC (2008), "Dig uncovers ancient roots of dentistry".
- Nair, C.G.R. (2004), "Science and technology in free India", Government of Kerala—Kerala Call, Retrieved on 2006-07-09.
- O'Connor, J. J. & Robertson, E.F. (1996), "Trigonometric functions", MacTutor History of Mathematics Archive.
- O'Connor, J. J. & Robertson, E. F. (2000), "Paramesvara", MacTutor History of Mathematics archive.
- Partington, James Riddick & Hall, Bert S. (1999), A History of Greek Fire and Gunpowder, Johns Hopkins University Press, ISBN 0-8018-5954-9.
- Peabody, Norman (2003), Hindu Kingship and Polity in Precolonial India, Cambridge University Press, ISBN 0-521-46548-6.
- Peele, Stanton & Marcus Grant (1999), Alcohol and Pleasure: A Health Perspective, Psychology Press, ISBN 1-58391-015-8.
- Piercey, W. Douglas & Scarborough, Harold (2008), hospital, Encyclopædia Britannica.
- Pingree, David (2003), "The logic of non-Western science: mathematical discoveries in medieval India", Daedalus, 132 (4): 45-54.
- Raja, Rajendran (2006), "Scientists of Indian origin and their contributions", Encyclopedia of India (Vol 4.) edited by Stanley Wolpert, ISBN 0-684-31512-2.
- Rao, S. R. (1985), Lothal, Archaeological Survey of India.
- Rodda & Ubertini (2004), The Basis of Civilization—Water Science?, International Association of Hydrological Science, ISBN 1-901502-57-0.
- Roy, Ranjan (1990), "Discovery of the Series Formula for by Leibniz, Gregory, and Nilakantha", Mathematics Magazine, Mathematical Association of America, 63 (5): 291-306.
- Sanchez & Canton (2006), Microcontroller Programming: The Microchip PIC, CRC Press, ISBN 0-8493-7189-9.
- Savage-Smith, Emilie (1985), Islamicate Celestial Globes: Their History, Construction, and Use, Smithsonian Institution Press, Washington, D.C.
- Schwartzberg, Joseph E. (2008), "Maps and Mapmaking in India", Encyclopaedia of the History of Science, Technology, and Medicine in Non-Western Cultures (2nd edition) edited by Helaine Selin, pp. 1301–1303, Springer, ISBN 978-1-4020-4559-2.
- Seaman, Lewis Charles Bernard (1973), Victorian England: Aspects of English and Imperial History 1837-1901, Routledge, ISBN 0-415-04576-2.
- Seidenberg, A. (1978), The origin of mathematics, Archive for the history of Exact Sciences, 18: 301-342.
- Sellwood, D. G. J. (2008), coin, Encyclopædia Britannica.
- Shaffer, Lynda N., "Southernization", Agricultural and Pastoral Societies in Ancient and Classical History edited by Michael Adas, pp. 308–324, Temple University Press, ISBN 1-56639-832-0.
- Sharpe, Peter (1998), Sugar Cane: Past and Present, Southern Illinois University.
- Siddiqui, I. H. (1986), "Water Works and Irrigation System in India during Pre-Mughal Times", Journal of the Economic and Social History of the Orient, 29 (1): 52–77.
- Singh, A. N. (1936), "On the Use of Series in Hindu Mathematics", Osiris, 1: 606-628.
- Sircar, D.C.C. (1990), Studies in the Geography of Ancient and Medieval India, Motilal Banarsidass Publishers, ISBN 81-208-0690-5.
- Smith, David E. (1958). History of Mathematics. Courier Dover Publications. ISBN 0-486-20430-8.
- Srinivasan, S. & Griffiths, D., "South Indian wootz: evidence for high-carbon steel from crucibles from a newly identified site and preliminary comparisons with related finds", Material Issues in Art and Archaeology-V, Materials Research Society Symposium Proceedings Series Vol. 462.
- Srinivasan, S. & Ranganathan, S., Wootz Steel: An Advanced Material of the Ancient World, Bangalore: Indian Institute of Science.
- Srinivasan, S. (1994), "Wootz crucible steel: a newly discovered production site in South India", Institute of Archaeology, University College London, 5: 49-61.
- Stein, Burton (1998), A History of India, Blackwell Publishing, ISBN 0-631-20546-2.
- Stillwell, John (2004), Mathematics and its History (2 edition), Springer, ISBN 0-387-95336-1.
- Subbaarayappa, B.V. (1989), "Indian astronomy: an historical perspective", Cosmic Perspectives edited by Biswas etc., pp. 25–41, Cambridge University Press, ISBN 0-521-34354-2.
- Teresi, Dick etc. (2002), Lost Discoveries: The Ancient Roots of Modern Science—from the Babylonians to the Maya, Simon & Schuster, ISBN 0-684-83718-8.
- Tewari, Rakesh (2003), "The origins of Iron Working in India: New evidence from the central Ganga plain and the eastern Vindhyas", Antiquity, 77 (297): 536–544.
- Thrusfield, Michael (2007), Veterinary Epidemiology, Blackwell Publishing, ISBN 1-4051-5627-9.
- Tripathi, V.N. (2008), "Astrology in India", Encyclopaedia of the History of Science, Technology, and Medicine in Non-Western Cultures (2nd edition) edited by Helaine Selin, pp. 264–267, Springer, ISBN 978-1-4020-4559-2.
- Wenk, Hans-Rudolf etc. (2003), Minerals: Their Constitution and Origin, Cambridge University Press, ISBN 0-521-52958-1.
- White, Lynn Townsend, Jr. (1960), "Tibet, India, and Malaya as Sources of Western Medieval Technology", The American Historical Review 65 (3): 522-526.
- Whish, Charles (1835), Transactions of the Royal Asiatic Society of Great Britain and Ireland.
- Our Science and Technology Heritage gallery for the National Science Centre in Delhi
- A brief introduction to technological brilliance of Ancient India (Indian Institute of Scientific Heritage)
- Science and Technology in Ancient India
- India: Science and technology, U.S. Library of Congress.
- Pursuit and promotion of science: The Indian Experience, Indian National Science Academy.
- India: Science and technology, U.S. Library of Congress.
- Indian National Science Academy (2001), Pursuit and promotion of science: The Indian Experience, Indian National Science Academy,
- Presenting Indian S&T Heritage in Science Museums, Propagation : a Journal of science communication Vol 1, NO.1, January 2010, National Council of Science Museums, Kolkata, India, by S.M Khened, .
- Presenting Indian S&T Heritage in Science Museums, Propagation : a Journal of science communication Vol 1, NO.2, July, 2010, pages 124-132, National Council of Science Museums, Kolkata, India, by S.M Khened,.