In 1897, he defended his thesis on the mines of Laurion, the silver mines near Athens, whose rich deposits and intense exploitation played a key role in the development of Athenian power in the classical period; it still remains a reference work on this subject. He also carried out excavations in the port of Delos and visited the Cyclades, Ionia, Lydia and Rhodes. In June 1894 he married a young Greek girl while he was in Athens, with whom he went on to have two children.
