In a remarkable chapter on the Roman Campagna Sir Archibald Geikie has given the facts relating to the geological formation of those hills, which were to become later the cradle of the Roman civilisation, when the volcanic platform of the Campagna, no longer increased by fresh eruptions, was carved by subaërial agencies into the topography which it presents to-day. Among such agencies, which were both chemical and biological, may be mentioned those which prepared the vegetable soil and clothed it with oaks and beeches on the hills, with laurels and myrtles along the sea-coast, and with reeds and equiseta on the banks of the river. Then came Man, who may have watched the last gigantic natural fireworks of the Alban volcanoes from Mount Soracte, which had by that time ceased to be an island.