LAST week Dr. Lionel Giles carried his illuminating survey of the historical and political development of China from the mythical and legendary periods to the stability under the Han dynasty. This week he will carry the survey forward to the birth of the Chinese Republic, discussing en route the invasion of barbarian tribes and tho division of the Empire into North and South, the ' Twilight Ages,' the reunification of the Empire, the Golden Age of the T'ang dynasty, the Manchu conquest and the great emperors of the seventeenth and eighteenth centuries.