The duties of the great officers of the empire were - (a) Maintenance of rivers. (b) To measure the land. (c) To inspect the mouths of the water being released from the main canals to the sub-canals. (d) To reward or punish poachers on the basis of their acts. (e) To collect tax and inspect all the businesses related to land. (f) To inspect woodcutters, carpenters, blacksmiths and miners.