The Cambridge History of India, Vol. I: Ancient India v1.c17.155

v1.c17.155

The advance of civilisation is seen also in the more extended knowledge of the metals: as compared with the gold and the *ayas*, of doubtful meaning, of the Rigveda, this period knows tin, lead, and silver of which ornamented bowls are made, while *ayas* is differentiated as red *ayas*, presumably copper, and dark or black *ayas*, which must be iron. Another sign of the new era is the definite references to the keeping of tame elephants, the guarding of elephants being one of the occupations occurring in the Yajurveda texts. But there is no hint that the elephant was yet used for war as it was already in the time of Ctesias. The use of horses for riding had certainly become more common; but no clear reference is made to the employment of cavalry in war, though that was usual by the time of Alexander’s invasion.