facts and circumstances, many of which are still verifiable by the geographical distribution of the existing rivers and mountain regions of the globe; and even if man, in the plenitude of his scepticism, were disposed to doubt, monuments exist, the undeniable work of human hands, under circumstances implying the existence of a social system which cannot well be misunderstood. “In the boundless annals of time, man’s life and labours must equally be measured as a fleeting moment;” but the Pyramids, and ruins of Karnac survive the Kaliffs and Cæsars, the Ptolemies and Pharaohs, and countless monarchs and dynasties prior even to them. Thus, whatever learned disputants may imagine as to the primitive occupation of the valley of the Nile, the date of its occupancy, and the race by whom it was first cultivated, we have in the Pyramids incontestable proofs of a vast antiquity. Whatever historians may say of the antiquity of ancient Rome, the _Cloaca Maxima_ of Servius alone refutes the beautiful romance of Virgil--how Lavinius and Turnus received Æneas ere Rome was; how Romulus and Remus founded Rome, and were succeeded by seven kings, none of whom ever in reality existed. But the existence of the _Cloaca Maxima_ and the researches of the illustrious Niebuhr tell another tale more consonant with what we know of man’s social and physical nature. In the most remote times, man early adopted those measures of self-preservation which nature or simple observation teaches him. History gives but little information as to the measures adopted by ancient nations to secure public health; and were it not for the remains of the _Cloaca Maxima_, so called, of Servius Tullius, we should be as ignorant as Virgil assuredly was of the ancient condition of Rome prior to the reign of the seven fabulous kings.[58] Unquestionably the ancient race which preceded those grand Romans who fill the page of history for nearly twenty centuries, had discovered such means, and adopted measures for the safety of the people. Authentic history, it is true, commenced with the Greeks and Romans, and the history of Germany dates from Cæsar and Tacitus; but the subjugation of the double-horned Rhine[59] must have commenced long before “the building of the city.”[60] But the world as known to the Romans, even during the reign of Trajan, was a contracted world compared to what it is now. The tropical regions of the East, and their vast populations, were wholly unknown to them; of Africa they knew but little, of Asia still less, whilst the New World was as if it existed not. Thus certain great problems in the history of mankind were never presented to them, problems having a basis in facts which men, for obvious reasons, are so unwilling to admit. The periplus of the Mediterranean might almost be said to form the Roman world; beyond the Rhine they made no conquests; the Danube formed their north-eastern boundary; the eastern shores of the Black Sea were but rarely visited