One place has been found and most completely investigated after the method of palæontological research, with all the help afforded by archæological and historical science, where, in overlying geological strata, the evidences have been found of a progressive development of culture from the end of the Stone Age down to the brilliant days of Græco-Roman history. There the chronological connection has been obtained, not only for the metal periods, but also for the end of the Neolithic Period. This most important place is Troy, the citadel-hill of Hissarlik, by the excavation of which Henry Schliemann has won immortal fame. Schliemann’s excavations, supplemented and completed in decisive manner by Dörpfeld, have brought about the most important advancement of the history of mankind that our age can show. [Illustration: A WINE MERCHANT’S CELLAR IN ANCIENT TROY Nine colossal earthen jars were discovered by Dr. Schliemann in the depths of the Temple of Athena. They had evidently belonged to some wine merchant’s cellar in the pre-Hellenic period. ] Virchow’s name is inseparably associated with Schliemann’s. Furtwängler, in his account, based on personal observation, of the results of the excavations at Troy, has accomplished the great service of exactly determining the chronological connections of the prehistoric with the historic eras, and thereby linking the former to history. On the spot on which tradition placed Homeric Troy (says Furtwängler) there really has stood a stately citadel, which was contemporaneous with the golden age of Mycenæ, the epoch of the Agamemnon of legend, was intimately related to Mycenæan culture, and at the same time corresponds most exactly to the idea of Troy underlying the old epic. [Sidenote: Seven Towns on One Hill] The citadel-hill of Troy terminates a ridge of heights stretching westward from Mount Ida, almost parallel to the Hellespont, and slopes steeply into the Trojan plain or the valley of the Scamander. The natural hill itself is not very high, but it was overlaid by enormous layers of ruins of buildings and walls, whereby it has been considerably increased not only in height, but also in breadth. Stratum after stratum lies one upon the other like the leaves of a bud, so that the history of the habitation of this venerable place from the most ancient times can be read from these strata which have been opened up by Schliemann and Dörpfeld, as from the leaves of a book. The original ground of the hill-plateau now lies some sixty feet above the plain, but the latter may have been raised something like sixteen to twenty feet by alluvial deposits since the Trojan War. The whole stratum of ruins lying on the original ground of the hill, which Schliemann opened up, amounts to about fifty-two and a half feet. Schliemann distinguished seven or eight different layers or strata, corresponding to as many towns which were successively built on this hill, one on the ruins of the other.