History of Technology in India, Vol. I: From Antiquity to c. 1200 A.D. v1.c26.s2.t2.3

v1.c26.s2.t2.3

Nearly a thousand copper objects that preceded the Harappan civilisation were found at Ganeswar; it appeared to be a manufacturing centre that employed copper ore from Khetri, and perhaps supplied the needs of nearby towns like Kalibangan, Mohenjodaro and Harappa (Agrawala, R.C., 1984, p. 157). Copper ore from the Aravalli range was certainly the source of the metal over a good part of the area (Agrawal amd Ghosh, 1973 (a), p.401). Scarcity of tin, which forms 10-20 percent of bronze, accounts for paucity of objects made of the latter, even though they are harder, keener and more cutting than those of pure copper (Agrawal and Ghosh, 1973,(a), p. 401). Iron is first noticed about 800 BC in a few megalithic sites; the Vedic word *ayas* is now believed to have first meant copper, which was later termed red *ayas*, after the use of iron, called either. white *ayas* or *loha*, became common (Chaudhuri, 1988, p. 321). Initial use of iron was for weapons or agricultural implements like ploughshares. Its real impact occurred after about 200 BC, when its carburation to steel incorporating about one percent of carbon was discovered (Agrawal and Ghosh, 1973,(b), p. 391) and the use of the bellows enabled greater heat intensity. Both bellows and iron ploughshares are frequently referred to by Pāṇini (Thakur, 1932, pp. 111-112).