The Cambridge History of India, Vol. I: Ancient India v1.c33.8

v1.c33.8

In Southern India there was no copper age, and iron probably did not take the place of stone until about 500 B.C. Up to that time the Āryans of the north seem to have possessed no very distinct knowledge of the south of the Peninsula, which was at once isolated and protected against invasion by the natural defences of the Vindhya hills and the trackless jungles of Central India, and when at last they penetrated through these barriers they found the Dravidian and other races in the south still in the neolithic stage of culture. The supposition that iron was first conveyed into Southern India by sea from Egypt, has nothing to commend it.²