"The Hindus seem to have been the first people to mine gold.... Much of the gold used in the Persian Empire in the fifth century before Christ came from India. Silver, copper, lead, tin, zinc and iron were also mined-iron as early as 1500 B.C. U The art of tempering and casting iron developed in India long before its known appearance in Europe; Vikramaditya, for example, erected at Delhi (ca. 380 A.D.) an iron pillar that stands untarnished today after fifteen centuries; and the quality of metal, or manner of treatment, which has preserved it from rust or decay is still a mystery to modern metallurgical science." Before the European invasion the smelting of iron in small char- coal furnaces was one of the major industries of India. The Industrial Revolution taught Europe how to carry out these processes more cheaply on a larger scale, and the Indian industry died under the competition... Europe looked upon the Hindus as experts in almost every line of manufacture—wood-work, ivory-work, metal-work, bleaching, dyeing, tanning, soap-making, glass-blowing, gunpowder, fireworks, cement, etc.21 China imported eyeglasses from India in 1260 A.D."