This section is from the book "Some Contributions Of South India To Indian Culture", by S. Krishnaswami Aiyangar. Also available from Amazon: Some Contributions of South India to Indian Culture.
Passing on from the political to the industrial condition of India, we have already described the principal sea-ports, both on the western and eastern seaboard. If, as has been pointed out, there were so many thriving ports and, if foreign merchants sought these for trade at considerable risk of pirates, and if there was so much enterprise in sea-going among the inhabitants of the country itself, the conclusion is irresistible that the country had a prosperous industry, and so, on examination, it appears certainly to have been. Apart from the complaints of Petronius that fashionable Roman ladies exposed their charms much too immodestly by clothing themselves in the "webs of woven wind," as he called the muslins imported from India, Pliny says that India drained the Roman Empire annually to the extent of 55,000,000 sesterces, equal to £486,9791 sending in return goods which sold at a hundred times their value in India. He also remarks in another place, "this is the price we pay for our luxuries and our women."
That the industrial arts had received attention and cultivation in early times in India is in evidence to the satisfaction of the most sceptical mind. The early Tamils divided arts into six groups: - ploughing (meaning thereby agriculture), handicrafts, painting, commerce and trade, the learned arts and lastly the fine arts. Of these agriculture and commerce were regarded as of the first importance. Flourishing trade pre-supposes a volume of industry, the principal of which was weaving then, as it also has been until recently. Cotton, silk and wool seem to have been the material that were wrought into cloths. Among the woollens we find mention of manufactures from "the wool of rats "1 which was regarded as particularly warm. There are thirty varieties of silks mentioned, each with a distinctive appellation of its own, as distinguished from the imported silks of China which had a separate name. The character of the cotton stuffs that were manufactured is indicated by the comparisons instituted between them and, 'sloughs of serpents,' or 'vapour from milk,' and the general description of these as "those fine textures the thread of which could not be followed even by the eye."
1 Mommsen gives the total £11,000,000, £6,000,000 for Arabia, £5,000,000 for India.