THE machinery of government as re-created by the Han out of what they inherited from earlier periods, to suit the needs of their unified empire, received later additions and refinements, notably in the T’ang period; minor modifications continued to be made by later dynasties, but its essential characteristics remained recognizable throughout the imperial period. The names of offices were changed, the size and number of local government areas was constantly being altered to suit local conditions, but the machine as a whole was never scrapped and replaced. By the Ch’ing period, therefore, though certain innovations were introduced by that dynasty, the institutions of government had the strength and acceptance that come of long establishment. Until the second half of the nineteenth century any opposition which existed was mainly of two kinds: first, anti-dynastic sentiment expressed in secret societies, aimed at expelling the alien Manchus and replacing them by a Chinese dynasty; second, spontaneous local uprisings 1 —peasant or tribal—neither of which aimed at transforming the whole government machine.