The chief river is the Pennar, which enters the district from Bellary on the west, and flows eastwards into Nellore.
The principal mining districts are those of Hazaribagh in Bengal and Nellore in Madras; in the former district the mica has usually a ruby tint, whilst in the latter it is more often greenish.
In the Inikurti mine, Nellore, "books" of mica measuring 10 ft.
The Sangam and Pennar systems depend on two weirs on the river Pennar in the Nellore district, the former about 18 m.
In the Madras districts of Nellore and Kurnool the indigenous breed has been greatly improved under the stimulus of cattle shows and prizes founded by British officials.